I’m forced to spell out again how I am so darn sure that CO2 causes some warming. Some of this seems like it’s too obvious but that’s probably because I work in optics and these equations are very familiar. When considering radiative absorption of CO2, we need to look at Plancks equation and the absorption curve of CO2.
The spectrum of CO2 is important to consider. Note that all the absorption is at the far right end of the curve – long wavelengths – with high transmission in the visible .3-.65 microns. Also for the water vapor guys, there is a couple of clear CO2 peaks which fall at water vapor valleys — bad luck guys. Anyway the absorption curve of CO2 in Fig 1, doesn’t extend into the visible range. It is transparent to visible light though and you can confirm it by the total atmosphere curve which is an addition of the gasses shown.
Then there’s this: From Wiki:
Planck’s equation states that
where
- I(ν,T) dν is the amount of energy per unit surface area per unit time per unit solid angle emitted in the frequency range between ν and ν + dν by a black body at temperature T;
- h is the Planck constant;
- c is the speed of light in a vacuum;
- k is the Boltzmann constant;
- ν is frequency of electromagnetic radiation; and
- T is the temperature in kelvins
So sunlight is about 5600 kelvin and the earth emits at about 285 Kelvin. Plugging the raw values into the above equation results in the graph in Figure 2.
See the flat pink line at the bottom? There you go, nice job Jeff, you’ve just proven that the Sun is brighter than the earth, brilliant!!
We know that the energy which strikes the surface of the earth is very nearly equal to the energy which the surface emits. There’s heat from the core, chemical energy released and not much else that I can think of that throw it a tiny bit out of balance, but these effects are very small in comparison to the total wattage from the sun. It’s so close that I probably shouldn’t have mentioned it as somebody may see it as a method of disagreement. Therefore the area under the energy-vs-wavelength transformed version of these two curves is equal for all intents and purposes.
So in Figure 3, I’ve scaled the graph to have equal incoming and outgoing energy.
So that’s how we determine the color of a lightbulb and the outgoing radiation of earth. An excellent graph below contains all of the points in this post overlaid. The internet is great, global warming in a few plots.
That’s all there is too it. The peak of the outgoing radiation lands almost perfectly on top of a CO2 spike. Incoming light goes right through the CO2, outgoing light get’s absorbed and re-emitted.
Radiative physics proven again.
The point is that any skeptical argument having any credibility at all, needs to start from this point. Yes CO2 causes some warming. After this, the world is your oyster and I’m no longer the guide.
the Air Vent 
On an email exchange I had with Trenberth via email on a different topic, he added this Part of that (downwelling radiation) raises surface temperatures but part of it goes into changing the hydrological cycle, rainfall, thus pumping heat (latent heat) into the atmosphere in ways unconnected to surface temperature. . So let’s stipulate that the world governmenteers are not aware of that as well.
urk.. are “aware of that as well.”
Once again Jeff, you insist upon making the same mistakes and are refusing to recognize that the troposphere contains great abundances of water in all three of it’s phases; vapor, liquid and ice. The absorption spectrum for the three phases of water are very different. The comparative absorption spectral diagram that you posted is irrelevant because it also fails to take this into consideration.
Once again, the absorption spectrum for liquid water in the atmosphere:
Note the location of the strongest absorption peak of liquid water and it’s unfortunate coincidence with the absorption peak for CO2, where liquid water absorbs 300+ times more intensely than CO2, not to mention water’s much greater abundance in the troposphere:
And what’s up with your figure 4, with an unknown provenance? I think I recognize that as a diagram the kid two blocks over from me put together for giggles, and yet you quote it as gospel? Why? Because you think that it confirms your preconceived notions?
Jeff, I think that you believe that CO2 causes warming because you want to believe that. Your belief is faith-based, because it certainly isn’t fact-based – not as you have presented it
This post is disappointing, I was hoping you could do better than this.
#3 Weird.
I’ve presented you with the absorption curves of CO2, the spectral distribution of the incoming and outgoing radiation. At this point I’m convinced that god and a hammer wouldn’t get through to you but you meet all types on line.
The spectrum of non CO2 atoms and molecules make a difference in magnitude of the effect only, not in the direction of the result. Tell me, how is it possible from these curves that incoming radiation is absorbed more by CO2 than outgoing? That is the single question, the rest is hand waiving.
Plot 4 is confirmed by my own calculations and plot 1.
You know, it’s hardly surprising that the “visible” spectrum coincides with no absorption peaks. If you think about it, if that wasn’t the case, there’d be nothing “visible” about it. Our eyes evolved to see in this particular gap. Pretty cool.
Other than wanting to note something pretty pointless, I have to say that I myself once kinda doubted the “greenhouse effect” concept. I think that the way it tends to get explained to the layman has the unfortunate effect that those of us who are smart instantly know something isn’t quite right.
But at the time, I didn’t know what absorption spectra were and was stuck on how the gases could let heat into the atmosphere in the first place. Of course, it’s radiation, and the difference is the wavelength. Much more sense than the “blanket”.
I think so too.
Re: #4
I was right. Your beliefs are faith-based. I won’t debate/discuss faith-based beliefs, as that is disrespectful. I am done with this thread.
Faith in a blackbody curve and the absorption spectra of CO2?
as I said before — weird.
Jeff Id,
I work in optics too so I have a tiny quibble on the “visible spectrum” which you quote as 0.35 – 0.65 microns. I realise it does not affect the substance of your arguments but my eyes work from 0.40 – 0.68 microns.
Lindzen says that the radiative balance is never truly “in equilibrium” and lately even the AGW blogs seem to agree. Yesterday “Skeptical Science” was fussing about the “Lost Heat”:
http://www.skepticalscience.com/Tracking-the-energy-from-global-warming.html
#9 Thanks, I was too lazy to look it up.
Jeff,
Sometimes blogs like this can get a little too intense. So here on a lighter note is Professor Gilbert Stead (Cantab) on the great Max Planck:
http://www.haverford.edu/physics/songs/cavendish/hv.htm
“Men of Harlech” is a really rousing Welsh song.
This is a nice set of graphs and a good blog post.
As CO2 is a trace gas compared to water one needs to look at the additional absorption that is not already absorbed by water. The 4um band is not overlapping water, but there is not much radiation there. The important bit is at 10.5 um where there is lots of radiation and CO2 is not overlapped too much by the water.
The atmosphere has two distinctly different parts and each should be described separately. Heat transport in the troposphere is dominated by convection and the latent heat in water vapor. Temperatures decrease steadily down to about -55°C at the tropopause. (dammit, why is there no degree symbol on a keyboard?) Above in the stratosphere, temperatures slowly increase from Ozone adsorption of UV. There is little convection and heat transport is controlled by radiation in the stratosphere.
The water has pretty much all condensed out at the tropopause and the dew point in the stratosphere is close to constant and is about equal to the temperature of the tropopause. Water simply cannot get above the tropopause. Example here:
http://www.climantartide.it/documentazione/lavori/2004-mean-vertical-profile.pdf
(This was a nice find as it is the 1st step in My Pet Theory)
My Pet Theory: I kind of believe in Miskolczi’s theory of constant optical density for the atmosphere and am working on a mechanism for how it could work. When CO2 absorbs a 10um photon it usually collides with other molecules before re-emitting the photon. Thus the entire layer of the atmosphere is heated and the CO2 only emits photons in compliance with the local temperature. If a parcel of moist air is ascending in the atmosphere is will stay a little warmer if it has additional CO2. The water will not condense out until it gets higher and the adiabatic cooling causes the temperature to drop more. The end effect is that the lapse rate continues to a higher altitude and the tropopause becomes higher and colder. This drys out the entire stratosphere because its dew point is controlled by the temperature of the tropopause. Less water in the stratosphere results in less IR absorption by water that balances the added absorption from the CO2. This provides a mechanism for Miscolczi’s theory of constant optical density.
It also provides for a temporary increase in optical density (and therefore temperatures) from an increase in CO2. The lack of convection in the stratosphere will result in a time lag for the dew point throughout the stratosphere to drop. This fits the recent statistical paper by Michael Beenstock and Yaniv Reingewertz.
One more thought, is that a parcel of moist air that rose to the tropopause will be dryer after the water freezes out at a higher altitude. The parcel will not be heated as much by IR from the ground for lack of water IR absorption. Thus vigorous convection will continue in the presence of additional CO2.
I’ll have to think about what happens to clouds with My Pet Theory.
#8 re #7
It’s called projection. However I might make one point in his favor. It is true that ice and water vapor do have different spectra. The problem is that they only occur over a part of the earth’s surface, that part with clouds. Where there are no clouds, CO2 does absorb energy that water vapor misses, as you point out. The effect of clouds on and by water vapor feedback is the real issue between skeptics and warmers.
Thanks Jeff,
I’m amused by Brego. He actually thinks that those of us who have worked with this stuff dont understand that the trop has ice in it. Why there is even recent work on how IR effects crystal growth. Oh well, I guess he’s right and the science that people use everyday successfully is wrong.
Brego: The study of ice on the troposphere is interesting. I think the first thing you need to do is think about whether or not ice is well mixed. But if you want to see how ice is handled for example start here:
Fu, Q., 1996: An accurate parameterization of the solar radiative properties of cirrus clouds for climate models. J. Climate, 9, 2058-2082.
Further you need to look above the troposphere to see where C02 is a real game changer. But basically we know that radiative physics is correct because it works.
I will ask my question here whilst people familiar with optic and spectroscopy are present. What is the limit on the absorption of CO2 due to pressure broadening around the ~15um bands?
This is the argument against saturation, but I have never seen it quantified, or any limits given. I have seen some data for it, but this is at the bands around 157um wavelength (-30MHz/Torr).
This question is one plank of the “how much warming does CO2 cause?” platform. What are the factors that the GCM’s – like MODTRAN use for this?
Jeff,
Radiative physics of CO2 may be what they are. Water vapour in its various forms and effects likewise. How to explain – in the face of increasing CO2 concentrations – the absence of “statistically significant” warming since 1998-1995 [take your pick as to the date] as has been argued not only by Lindzen and others for some time, and admitted recently by none other than Phil Jones in a BBC interview, but more importantly, acknowledged by the WMO at their 2009 annual meeting?
Might it have something to do with the fact that the earth’s atmosphere is one of the utmost complex non-linear systems known to man? A system that, it should be pretty clear by now, we understand very little about with certainty, mistaking as we do recurring cycles for actual change. And in all of that uncertainty we purport to understand the actual role of man’s activities?
@#15,
read about “saturated gassy argument” over at real-climate and read the comments. In the comments, (around #10 I think) Dr. RayPierrehumbert remarks that to get to saturation in the Angstrom sense requires 10 bars of surface pressure. I separately wrote to him to see how many ppm that might translate into, and he replied that 100,000 ppm is equivalent to 0.1 bar and you’d have to get rid of the ocean and see a runaway greenhouse effect before you’d see saturation in the Angstrom sense.
Stephen Mosher #14, there is something valuable that Brego has contributed here: Namely the problem with qualitative arguments.
Yes frozen and liquid water matter, the question is by how much. Of course the people who know how to do the calculations and run the codes know how to take into account the tiny fraction of water in the atmosphere that is frozen or liquid (clouds as it were).
I’ve worked in areas in science where people make similar mistakes: People find a potential confound and hop all over it because they lack the training or resources to carry it through to a numerical conclusion.
But of course clouds are the bull in the china shop here. In an ideal layer of air (just vertical convection, no weather or other effects), you can compute from first principles the amount of warming from the GHGs in the atmosphere. The real atmosphere is more complex, but Jeff’s point is a good one, and any way we do know it isn’t that bad an assumption because simple radiative physics gets pretty darned close to the right answer for the average surface temperature.
#11
That song was adopted by the Faculy of Science at Sydney University as the Faculty song.
A couple questions Jeff. figure 4 shows outgoing IR at a BLACKBODY 255k. Let’s ignore the fact the earth isn’t a blackbody and maybe you can tell me how much that curve shifts as the temperature warms. I believe it will go towards the left reducing the amount intercepted by CO2, but how much I DON’T know.
Don’t know
How does this variation integrate over the surface of the earth with day/night and tropics/poles variations in the radiative temp??
It changes the result for sure. The outgoing radiation slides left and right a little tiny bit.
That is also one of those perverted graphs that does not indicate the magnitude of the earth radiation being magnitudes smaller than the suns. Talking about the magnitude at the surface totally ignores the magnitude of radiation absorbed in the atmosphere, not reflected, before reaching the surface!!!!
You say above Figure 2 that the earth emits at 285 and figure 4 says 255????????????
The average temp of the earth is something like 15C. If you add 273 +15, you get 288 K. I’m an engineer so for stuff like this I used approximate numbers with a shoulder shrug. Kinda like the visible spectrum numbers someone corrected me on. The other graph says 255, I think it’s kind of low but all that means is you need to imagine the outgoing radiation shifted a few pixels to the left
You do know that CO2 lasers work on the COLLISION of other gases against the CO2 molecules to add energy for emission?? Why do you ASSume that all of the radiation from the CO2 emissions in the atmosphere is specifically coming from ground IR??? That is, your and others assumption is that CO2 warms the atmosphere but does not cool it also?
No, I don’t make that assumption. All I did was show that the outgoing radiation is absorbed more than incoming radiation
Isn’t it true that all gasses will emit the same Planck curve as solids if it is at the same temp?
Your figure 4 shows that incoming IR passes a number of bands of H2O absorption. That would appear to mean that atmospheric water vapor would be heated by that incoming as little reaches the surface!! What do you thinks heats the atmosphere more, the large amount (comparatively) of H2O absorbing both ways or that tiny bit of Co2??? That H2O mostly being in the troposphere and not spread higher!!
Water, absolutey.
You totally ignore the O2 & O3. The fact that they cover only a tiny bit of the outgoing band is easily made up by the fact that there is a huge amount of it. They also absorb virtually all of the incoming ultraviolet again adding much more heat to the atmosphere than CO2.
You are right, I did ignore it b/c it’s moot. The other gasses are often stronger warmers as the spectral plots show. The point here is that CO2 creates a warming effect, whether it’s dangerous or even measurable is a whole different question
Yes, CO2 does absorb and emit. So what. You still haven’t proven it warms anything in a way I should take notice of much less worry about!! You haven’t even proven that cute little thought experiment that alledgedly gives you the atmospheric sensitivity for CO2. What you really computed was the atmospheric sensitivity AS A WHOLE!!!!!!!
I absolutely and unequivocally did NOT calculate atmospheric sensitivity. I have not proven that any of the warming would even be measurable with current instruments. I’ve written nothing about feedback,convection or anything else. You have found a number of good issues which need proper addressing to claim CO2 is a dangerous warming gas, I have demonstrated that despite that problem, CO2 is at least a mild warming gas. Mild meaning anything between 0 and 2C per doubling with possible additional feedback warming or cooling coming frmo other things.
My guess is that there are negative feedbacks in the atmosphere such that even the 1.2C claimed by so many from simple calculations is exaggerated, but it is only a guess. I’ve proven nothing of the magnitude of warming here. I’ve read some feedback papers and was unconvinced that we really know anything WRT the true warming magnitude.
The purpose of this post is to show skeptics that they don’t need to fear the radiative physics in order to make the same points. It’s probably my first post where I actually attempted to focus the debate to what limited means I can. All of your other points are fine and work just the same whether CO2 captures outgoing radiation or not.
Tetris:
First, don’t muddy the question with BBC interviews or other piffle. The science is the science.
First, CO2 and temperature don’t enjoy a linear relationship with each other, it’s much more complicated.
Secondly, CO2 is a driver, but not the only driver, there are natural atmospheric ocean oscillations that over the time scale of 1980 (dawn of AGW according to the models) to now have much larger amplitudes than the (so far fairly small) secular drift predicted by CO2 increase.
That’s why short period observations that don’t explicitly take into account the oscillations are pretty much useless for arguing whether CO2 affects climate or not.
I always want somebody that doesn’t think CO2 is GHG to explain why the surface of the Earth is 33°C or so warmer than it would be without the GHGs. How does that work out in a universe where GHGs don’t exist?
kuhnkat:
Gray body’s don’t absorb as much heat, making the surface temperature cooler than it otherwise would have been, this shifts the curve to the right, not the left (though by an amount that doesn’t matter at first order).
That’s all well understood and included in more detailed models (for example, re-radiation can be included in two-layer models of the radiative physics).
You appear to have trouble dealing with the concept of orders of approximation. “Kitchen sink” models that include every possible effect under the sun, aren’t particularly illuminating in explaining how a particular effect arises to start with.
Chriskafe, (#19),
The faculty in Sydney should be commended for overlooking the fact that Gilbert Stead was a “Pom”.
Here in the USA, all it takes is free beer to get the graduate students singing the song.
RB thanks.
15-I was under the impression that MODTRAN was a radiative transfer model. A General Circulation Model is another-much more ghastly complicated yet still too simple-sort of beast.
Yes we all know CO2 absorbes about 8% of the outgoing long wave radiation,once its acted upon that percentage it can have no furthur effct!
Good post. The physics here is correct, with one minor revision. Both water and CO2 do absorb in the solar portion of the spectrum. Not in the “visible” (400-700 nm) portion, but at wavelengths longer than 700 nm. So there is an absorption there that must be accounted for as well. This does not change the fundamental argument of the post, only modifies it a bit.
A related discussion is going on here:
http://claesjohnson.blogspot.com/
Quite illuminating, especially in relation to this discussion.
Sorry, i don’t agree with “Yes CO2 causes some warming”.
Your plot said the contrary : if the heat is reemitted only there, it is because the “blue absorbtion” fall and cannot contain any more the heat. And the peak of CO2 at the very same place prove that the CO2 cannot stop that heat.
For Kuhnkat, #20
“..figure 4 shows outgoing IR at a BLACKBODY 255k. Let’s ignore the fact the earth isn’t a blackbody and maybe you can tell me how much that curve shifts as the temperature warms. I believe it will go towards the left reducing the amount intercepted by CO2, but how much I DON’T know.”
The earth isn’t a blackbody but at the wavelengths of interest it is pretty close for most surfaces (e.g. 0.98). You can see a lot of emissivity curves for different surfaces at The Dull Case of Emissivity and Average Temperatures
The curve shifts according to Wien’s law which says that the peak wavelength of radiation in um = 2898/T (where T is in kelvin).
E.g. at 288K (15’C), peak wavelength = 10.1um
at 255K (-18’C), peak wavelength = 11.4um
at 303K (30’C), peak wavelength = 9.6um
“..How does this variation integrate over the surface of the earth with day/night and tropics/poles variations in the radiative temp??”
It has some effect, but note that the radiation is across quite a wide band. So if you calculate the radiation within a particular wavelength range and see how it changes with temperature the change in radiation is not large. You can try it at http://spectralcalc.com/blackbody_calculator/blackbody.php
But of course the effect is there and taken into account when the radiative transfer equations calculations are used.
[now trying the unusual blockquote tags..]
<blockquote cite="That is also one of those perverted graphs that does not indicate the magnitude of the earth radiation being magnitudes smaller than the suns. Talking about the magnitude at the surface totally ignores the magnitude of radiation absorbed in the atmosphere, not reflected, before reaching the surface!!!!"
The idea behind this graph is that the solar radiation absorbed by the climate system is of a similar magnitude as the outgoing radiation from the climate system. What should Jeff have shown?
Any representation can be criticized as the solar radiation absorbed by any surface depends on time of year, time of day, latitude, current weather conditions… This graph isn't the mathematical solution, it's just atmospheric physics 101 to introduce the subject.
Solar radiation at the top of atmosphere is about 1367 W/m^2.
Solar radiation annually globally averaged is 342 W/m^2. (=1367/4)
Solar radiation absorbed (annually globally averaged) by the climate system is about 239W/m^2 (earth's average albedo is around 30%), of which around 170W/m^2 is absorbed by the surface and the balance by the atmosphere.
<blockquote cite="You say above Figure 2 that the earth emits at 285 and figure 4 says 255"
The most interesting one of all..
The earth’s surface is, on average, about 288K or 15’C. This equates to a radiation, from Planck’s law, of around 390 W/m^2.
We can’t really average the temperature and then calculate the radiation, but if we calculate the radiation at every hour of the day for every place around the world, calculate the radiation and then average the radiation – we get around 396 W/m^2.
And yet 255K equates to about 240W/m^2.
How can the outgoing longwave radiation from the top of the atmosphere be only (about) 240 W/m^2 while the upward longwave radiation from the surface be 396 W/m^2?
The numbers are correct. The explanation is that the atmosphere absorbs some of the radiation from the surface and re-emits it in all directions. Some of this is back down. Therefore the surface receives more radiation than it would if the atmosphere didn’t have this property.
Some call this the “greenhouse” effect.
When you talk about water versus CO2 absorption bands (and liquid versus ice versus vapor) it is important to note that at the effective emitting layer of the atmosphere (at about 255K on average), the vapor pressure of water is very low, so there is not much around. Certainly above the troposphere, there are very few clouds (ice), no liquid water, and very little vapor.
So the radiative loss really is “significantly” reduced by additional CO2 that lies between the emitting level of the atmosphere and space, and doubling the CO2 will force the emitting layer to warm slightly (~1C) to compensate for the back-emitted radiation from CO2 that is ABOVE the emitting level.
The real argument is (and always has been) how much amplification of this ‘CO2 only’ warming will take place; and there remains great uncertainty, no matter how much AGW activists scream and stamp their feet.
#30 scienceofdoom
Thanks for “the numbers” supporting Jeff’s point that additional CO2 causing warming as it expands and clarifies his initial presentation. That CO2 is a greenhouse gas is in itself physically factual; mankind is adding to the atmosphere in a reasonably quantifiable amount is also a fact. Hence, it is entirely reasonable to assert that within a control volume of sky/earth/ocean there is heating from man-made CO2 that is occurring that wouldn’t be if humans weren’t emmitting CO2.
“Reasonable to assert” and “proven” in this model are not equivalent (nor am I claiming anyone is committing this fallacy I’m just making an attempt at clarity…) and in my thinking, in a system as complex as earth climate with potentially negative (or positive) feedbacks, any proof has to rely on measurement; in this case temperature measurement, or heat-flux measurement although I have to admit my ignorance on how heat flux measurement would be done directly as a practical exercise.
“Cold snowy winter disproves AGW”…”Hottest March on Record confirms AGW”…disappearing ice caps; ice caps at average – just fine thank you…it’s like watching a football match.
Surface temperature measurements have been used to support/disprove AGW but have been shown to be uncertain, unreliable, scant reference is made to these limitations, and perhaps not even relavent to global temperature; after all, thermometers are situated approximatly six feet off earth surface, and poorly distributed spacially. Atmosphere and oceans need better measurements.
A point to be made here is that we should be able to measure CO2 warming and the focus should be on measurment; and then we can test and quantify the warming effects of added CO2.
Carrick Post 21
” I always want somebody that doesn’t think CO2 is GHG to explain why
the surface of the Earth is 33°C or so warmer than it would be without the GHGs.
How does that work out in a universe where GHGs don’t exist? ”
I’ll have a go at my partial explanation..(with a few kitchen sinks thrown in for good measure..)
“GHG”s in this sense slow down the rate of escape of heat from the earth’s surface / atmosphere.
Any atmospheric constituent that abosrbs heat or is heated (by radiation) must loose that heat.
Gases due to their chemical bonds, and because they are (relatively) free to move around, can loose some heat by conduction (and / or convection).
But gases that can radiate IR can loose more heat and more quickly, than by conduction (and / or convection) alone.
“GHG’s” can not trap heat, they have to loose it by conduction, (and / or convection). If a gas can also radiate (heat) it can loose heat faster,
so is less of a “GHG”. The only way a gas can “trap” heat is by changing heat to the latent heat of change of state. Water is the only atmospheric constituent that can do this (change of state within atmos. temps and pressures found it the atmosphereof this planet), and does so in massive amounts. Water can also transport massive amounts of cold down in the atmosphere as cool rain, undeniably cooling the atmosphere at lower levels and the earth’s surface where it lands. As liquid water has such a high specific heat content this is a massive effect globally, usually seemingly ignored in IR / radiation / energy budgets discussions.
Gases like O2 and N2 are heated by conduction AND radiation, as mentioned in post 20 by kuhnkat. They can only cool by convection and conduction.
Gases like CO2 can be warmed by conduction AND radiation. CO2 (and similarly presently described “GHG” gases) can also “store” heat in a changing chemical bond, which can be released to a lower energy state chemical bond by radiating a photon. They can cool by conduction, convection, AND radiation.
Water can be warmed by conduction, convection, AND radiation. I am assuming water has very many differing forms of it’s chemical bondings, andin changes of these cause it’s such wide spectra. It can cool by conduction, convection AND radiation. Water further complicates things because it can also “store” heat in a different form namely, latent heat (of change of state), which it can either absorb or release depending upon the change of state. Many think of this as evapouration, but it is really vapourisation. H20, is peculiar, it is a very light gas, but yet a very heavy liquid, and then a lighter solid.
Elsewhere physicists say CO2 (gas) has a very high specific heat content, yet chemists say their mass equations work with CO2 having a very low heat content. ?
From the above it seemingly appears that
O2 and N2 will insulate the atmosphere best from heat escaping. O2 also seems to have a good heating capacity as well. (the actual greenhouse gases)
CO2 within an atmosphere (chemists mass calculations) has a low specific heat and therefore acts as a cooling agent because it can radiate heat.
CO2 (mostly) aids cooling the atmosphere by radiating heat, as well as possibly some heating by thermalisation.
Water is the daddy of both warming and cooling, and in it’s differing states / abilities seems to cloud the picture beyond recognition.
IF Brego is correct in his comments (and I strongly suspect he is) regarding it’s liquid ability to emit CO2 wavelength IR then all present interpretations of “measured” IR flows and plots are seemingly possibly massively misinterpreting “things”.
It could easily “explain” what I suspect is an order of magnitude misinterpretation of latent heat movements
found in all the present W/m2 based global energy budgets,
by atributing massive amounts of energy (thermal radiation) measurements / movements to CO2, when they should be to H2O.
My “understanding” may well be summed up as, our present versions of the greenhouse effect are
probably way off the actual effects, and players responsible for what.
I suspect we have the actual effects and players almost perfectly reversed.
O2 (20%) both heats and insulates the atmosphere, and N2 (79%) also insulates.
CO2 (0.04%) is a powerful cooling agent, that can also warm of occasion.
Water (variable %) does both warming and cooling by a variety of mechanisms (and has more mechanisms) that dwarfs all other players.
Furthermore, space is not cold, how can nothing have a temperature, space has no temperature, the earth is just an object in space. It’s temperature is mostly “governed” by a balance between constant solar input and losses, however there is the massive influence of the oceans on a daily and longer term basis as the oceanic currents and phases change, we know not how or when they will change. They will change however. We do know the oceans have a heat capacity in excess of 800 times the heat capacity of the thin film of an atmosphere that covers this planet.
How thin is the atmosphere, if the earth were a soccer ball, the atmosphere would be a layer of cling film.
I do not agree with the calculations or assumptions used to suggest the planet is 33 degrees warmer than it would be otherwise,
for virtually all the reasons mentioned above, and many more not covered yet.
That is not to say the earth is warmer than it would otherwise be, it is partently,
but why, it may not be a greenhouse effect at all.
Photons do move at the speed of light (186,000 miles per second) afterall
– in an atmosphere mostly contained in under the first 32 kilometres, that’s merely an instant.
The earth is the temperature it is, we know not why, or how.
Trying to justify a false dogma by claiming a certain temp above what would otherwise be,
is merely another form of pandering to the consensus.
Something no science should ever do.
This is before mentioning the second law of thermodynamics and “all radiation is positive”……
Jeff, you’ll have to let me go slowly.
I have question and a statement.
I understand that certain wavelengths of energy hitting a CO2 molecule, are absorbed by the CO2 and then radiated out again at different, longer wavelengths.
Why does that increase the temperature of the other elements of the atmosphere to a greater extent than would occur if the incoming energy, in the absense of CO2, hit those other atmospheric elements directly?
Now for the statement. For “the physics to be settled”, I would expect to also see a statement as to why (for example) the Central England temperature record has been increasing in a linear fashion since 1659 (residuals R squared = 0.000008, which to me indicates that the NUL hypothis still stands: THAT changes in atmospheric CO2 levels do not visibly affect the temperature over very long time scales).
You help in these two matters would be appreciated.
GregO: said (#32)
“..and in my thinking, in a system as complex as earth climate with potentially negative (or positive) feedbacks, any proof has to rely on measurement; in this case temperature measurement, or heat-flux measurement although I have to admit my ignorance on how heat flux measurement would be done directly as a practical exercise..
..Surface temperature measurements have been used to support/disprove AGW but have been shown to be uncertain, unreliable, scant reference is made to these limitations, and perhaps not even relavent to global temperature; after all, thermometers are situated approximatly six feet off earth surface, and poorly distributed spacially. Atmosphere and oceans need better measurements.
A point to be made here is that we should be able to measure CO2 warming and the focus should be on measurement; and then we can test and quantify the warming effects of added CO2.”
On surface temperature measurements and ocean heat, I agree, see Why Global Mean Surface Temperature Should be Relegated, Or Mostly Ignored and The Real Measure of Global Warming
On “..any proof has to rely on measurement; in this case temperature measurement, or heat-flux measurement although I have to admit my ignorance on how heat flux measurement would be done directly as a practical exercise..”
This is the area of most confusion I think. Understanding radiative physics is challenging to the newcomer in detail although the concepts of absorption and re-emission are reasonably straightforward. But still, it is foundational physics.
The key point is that climate is very complex. Can we expect to measure some simple correlation between CO2 and surface temperature and ocean heat? No. Skeptics and “consensus” climate science are in agreement as far as I can see. (Although it often doesn’t appear so in the blog wars).
So what we can do is measure the actual radiation (upward & downward) at the earth’s surface for given situations and compare it to the theory. To do this properly (line by line absorption) requires reasonable computing power. To approximate with band models is much simpler.
The theory and the measurements match pretty closely. Why not exactly? That’s the situation with most real-world problems vs models. For this problem.. In the case of absorption exactly how much water vapor, CO2, tropospheric ozone, methane etc are present in the vertical profile through the atmosphere. In the case of re-emission exactly what is the temperature profile of the atmosphere (needed to calculate the Planck function of radiation)? (For the purists, we also need to know the same vertical profile of trace gas concentrations to calculate emission)
An interesting example of theory vs practice can be seen at CO2 – An Insignificant Trace Gas? Part Six – Visualization
What’s missing?
The rest of the climate system! An example I used in one article, New Theory Proves AGW Wrong! was that when there are problems in predicting/projecting temperature many people point to CO2 and say “see, the CO2 theory is wrong” and yet when there are problems with climate models on ocean circulation no one (?) is saying “see, angular momentum is so bogus!”
This might not seem like anything major but this is probably coming back to the point of our host (although I have only just showed up so I’m not certain). Some things in physics are very clear, some things are not so clear. Radiative physics is very clear.
CO2, water vapor, methane, ozone and a whole collection of other trace gases are well understood in their impact on radiation through the atmosphere. Some of the profiles of the trace gases are hard to figure out, especially ozone. But that doesn’t invalidate radiative physics. In this case stratospheric chemistry is more the issue. Or observation of initial conditions.
In climate most areas are less clear than the radiative effect of CO2.
Scienceofdoom re 35
you said – QUOTE In climate most areas are less clear than the radiative effect of CO2 UNQUOTE
The theory (you say) is clear.
In practice, it has no visible impact on temperature.
What’s right?
Theory or measurement?
Which quantitative equation in physics describes the amount of heat produced by shining a light of (whatever) wavelength through a large thickess of pure CO2, large enough to be “infinitely” thick?
Re: Geoff Sherrington (Apr 20 08:05),
For high optical thickness, the Rosseland approximation to the RTE is the one to use.
Ausie Dan: #36
“The theory (you say) is clear.
In practice, it has no visible impact on temperature.
What’s right?
Theory or measurement?”
What I’m trying to explain is that both theory (radiative transfer equations) and measurement (upward and downward longwave radiation) match in the field of radiative physics.
What is more complex is all of the other factors in climate.
The issue is whether we are talking about radiative physics = the “greenhouse” effect or AGW. Many people think they are one and the same. But they are not.
Understanding each cause in isolation is the only way to make progress. The “greenhouse” effect is a foundation relied upon for AGW, but is not AGW.
AGW could be wrong and the “greenhouse” effect still be right – for example, if someone demonstrated a strong negative feedback with clouds.
It’s possible that someone will prove the “greenhouse” effect wrong – but much less likely. It’s possible to prove gravity and the theory of angular momentum wrong as well. Unlikely, but possible. All scientific theories have to be falsifiable.
Ausie Dan,
You seem to misunderstand what CO2 is doing. It absorbs infrared radiation in its absorption band(s), which pushes it into an “excited” state. The CO2 molecule that absorbed the infrared can transfer the energy to other (surrounding) molecules in the air, causing warming (sensible heat), but more often than not it will simply re-radiate that absorbed infrared in a random direction (up, down and sideways… all possible directions). The portion re-radiated in the direction of space continues on its way out, but the portion that happens to be re-radiated back toward earth will be absorbed lower down in the atmosphere. Maintaining a thermal balance (visible radiation absorbed at the surface must ultimately find its way out to space) requires that the emitting level of the atmosphere must warm very slightly (~1C) to maintain that energy balance.
Derek,
“Furthermore, space is not cold, how can nothing have a temperature, space has no temperature, the earth is just an object in space.”
I almost don’t know where in your long post to start Derek, but maybe the above is a reasonable point. Space is very, very cold. In fact, about 4K, as was shown by Arno Penzias at Bells Labs, via his famous microwave background radiation measurements, for which he won the Nobel Prize for physics. The radiative spectrum of a “black body” at 4K exactly matches the microwave spectrum that Penzias measured coming from space, in every direction he looked. Penzias’ work led to the ‘big bang’ theory of cosmic evolution, where the cosmic microwave background is assumed to be the ‘afterglow’ of a big bang that formed the universe. Any object left in space that does not receive energy from an internal or external source (like the sun) will gradually cool by radiative loss to space until it approaches the background temperature of space… 4K.
There are lots of reasons to question extreme projections of global warming from CO2, but the basic radiative physics of CO2 is not one of them. Please note that every well known skeptical climate scientist (Richard Lindzen, Ray Spencer, and others) accepts and agrees with the basic radiative effects of CO2. You have also seen posts on this thread and several other threads at TAV by practicing scientists in a number of other fields, all in agreement with the basics of radiative physics. This really is not something on which there is any scientific disagreement.
Thanks scienceofdoom for the patient explanation.
#33, we discussed O2-N2 etc at Comment #56 onwards here . You also have issues with the second law, so you might not find the discussion useful.
30, Scienceofdoom
“The most interesting one of all..
The earth’s surface is, on average, about 288K or 15′C. This equates to a radiation, from Planck’s law, of around 390 W/m^2.
We can’t really average the temperature and then calculate the radiation, but if we calculate the radiation at every hour of the day for every place around the world, calculate the radiation and then average the radiation – we get around 396 W/m^2.
And yet 255K equates to about 240W/m^2.
How can the outgoing longwave radiation from the top of the atmosphere be only (about) 240 W/m^2 while the upward longwave radiation from the surface be 396 W/m^2”
Most radiation to space doesn’t come directly from the surface; it comes from the air rather high in the troposphere. Maybe 255 K is about the averate temperature of that air? I don’t think you really need a “geenhouse effect” to explain this. MAYBE it explains it; maybe not. We do know that a real greenhouse works only because convection is blocked.
As you said, “It’s possible that someone will prove the “greenhouse” effect wrong – but much less likely. It’s possible to prove gravity and the theory of angular momentum wrong as well. Unlikely, but possible. All scientific theories have to be falsifiable.”
I would sure like to find a way to test the falsifiability of this theory.
Correct me if I’m wrong, but it seems to me that JeffID’s original post was simply stating that CO2 molecules in the atmosphere absorb a higher amount of the outgoing spectrum of radiation from earth’s surface than they do of the incoming spectrum of radiation from the Sun. This means that if there are CO2 molecules in the atmosphere, the radiation going out from they affect the balance, preserving some of the heat that reaches the earth. This is exactly what a Greenhouse gas does.
Whether or not CO2 increasing makes a measurable difference, or causes more negative or positive feedbacks, or what percentage of the net increases that have been observed we are directly responsible for, is where the debate should be waged, not on the fundamental physics of how a CO2 molecule absorbs radiation, which is something that can be clearly demonstrated in a lab.
A true skeptic’s argument is that we do not know most aspects of this with any degree of certainty, and furthermore we don’t know what if any negative effects would come of the unknown degree of warming that may or may not be directly attributable to us, therefore, in the absence of certainty, any political decisions that are made supposedly on the basis of “settled climate change science” are political decisions, not scientific ones.
A non-skeptic’s argument is that there is consensus where there is none (anyone who questions anything is decried as a denier, even though questioning something is not the same as denying it), the science is settled (science is never settled. The day science is settled is the day science ceases to exist), and if we don’t act now, time will run out (in X number of years, replace X with whatever number generates the most hysteria) with presumably disastrous consequences for everyone.
Since the scientific approach is a skeptical one, it is clear that anyone who does not allow for questioning decisions based on uncertainties is not acting scientifically. End of story. As long as there remain significant uncertainties, there is no clear scientifically sound consensus. Any purported consensus, either for or against AGW therefore is suspect and non-scientific until the enormous levels of uncertainty are decreased by more than just a statistically significant margin. This requires significantly more accurate measuring, more robust testing of hypothesis, and continuously questioning until clearer answers are found.
It’s my understanding that all the warming caused by CO2 has already been exceeded, and no significant warming do to this analysis, can take place. It’s only through ‘the mythical feedback’ mechanism(unproved) that more warming has been included.
In other words at some point the CO2 concentration in the atmosphere reaches steady state heat balance, a constant, balancing out the radiation budget. As more CO2 is added, nothing happens to the heat balance, it’s now reached steady-state … And that constant point happens at about half today’s CO2 concentration.
The old, try and block light transferred through a window, by successive coats of white paint. Each added coat produces less and less light blocking.
#44 You have my point correctly, the post is intended to convince people that there is a central bit of information in warming which cannot be reasonably denied. When you do argue against or for AGW, the central point needs to be understood clearly b/c it is what it is. As far as the uncertainty argument, everyone seems to have their own views and I can’t argue easily with them.
#45, Adding more CO2 will always cause more warming, but the increases are diminishing as concentrations rise.
Yes, I should have said that — It’s logarithmic, and at around half today’s concentration we are about 95% there …
Same as with my painted window explanation. Successive coats have logarithmic contribution to blocking more light, and after a few coats it’s basically all you can get without massive numbers of added coats. And even then, the added light blocking is minimal.
What I am searching for is an easy way to explain that others(not scientific types) might understand.
Here is an expanded version of a post that I made back in early March. Maybe Jeff will let me reproduce it here.
Addition of CO2 into the Earth’s systems has a potential to decrease the out-going long-wave radiation. We do not yet know that this has in fact occurred.
Recently I ran across the following comments on a blog. The comments are followed by my response.
1. “The physics of the direct warming effects of increased concentrations of CO2 and other infrared-absorbing gasses is completely clear.”
Let me try, “The physics of radiative-energy transport phenomena and processes given changing compositions of CO2 and other infrared-absorbing gasses in a homogeneous mixture of gases is completely clear.”
In fact, I think this can be expanded to include all radiative-energy transport phenomena and processes, ( absorption, transmission, and reflectance ), for both ultra-violet and infrared radiation, so long as homogeneous mixtures of gases are the material.
For me, one question is, How does this relate to the Earth’s atmosphere, oceans, ice, and land, and all the materials in and on these, and all the phenomena and processes occurring within and between these?
2. “So, yes, one must combine this measurement of anthropogenic CO2 with the simple radiative physics in the atmosphere to get the fact that we expect AGW.”
The radiative-energy transport phenomena and processes occurring in the Earth’s atmosphere are far from ’simple’. If these were simple, I think the treatment of them in mathematical models could be fairly characterized as being based on the full and complete fundamental equations associated with these, depend solely on properties of the materials of interest free of any parameterizations, accurate numerical solution methods known and fully incorporated into all GCMs, and resolution of all temporal and spatial scales accurately resolved for every calculation.
So far as I am aware, none of these conditions are met. The parameterizations for some of the phenomena and processes associated with radiative-energy transport in the Earth’s atmosphere are in fact used to tune the GCMs when improvements in hindcasts are needed. The properties of materials as they appear in the fundamental equations for any phenomenon or process are never used as tuning knobs.
I’ll add now, that R. D. Cess, V. Ramanathan, G. E. Thomas, K. Stamnes and a few other people might be surprised to learn of the simplicity of radiative-energy transport calculations in the Earth’s atmosphere. The earth’s atmosphere is not a homogeneous mixture of gases; it’s far more complex. Some of the materials that make the Earth’s atmosphere a heterogeneous mixture of gases, vapor, liquid, and solids have critically important interactions with the radiative energy transport.
Recently, I also ran across this statement in an online kind-of textbook:
“To develop this understanding we must discuss various forms of energetic equilibria in which a physical system may reside. Earth (and the other terrestrial planets, Mercury, Venus, and Mars) are said to be in planetary radiative equilibrium because,on an annual timescale the solar energy absorbed by the Earth system balances the thermal energy emitted to space by Earth.”
The writer has specified a time scale over which the in-come and out-go of radiative energy for the Earth’s systems are balanced; ‘annually’. In my opinion there is no foundation whatsoever for this statement. By the same token, I think that this is the first time that I’ve seen any temporal scale attached to the radiative-equilibrium hypothesis. This one is clearly unsupported, however. The Earth’s systems both receive and reject energy on all temporal and spatial scales. Yes, the Earth’s systems, at this very instance, are losing energy to deep space and this seems to be frequently overlooked.
A Few of the Un-Tested Hypotheses:
1. The Earth’s systems at some time in the past were in a state of radiative-energy balance, and will again be at some time in the future in radiative-energy-transport balance, between the energy supply source from the Sun and the energy sink from Earth into deep space.
2. Experimental measurements and theoretical calculations show that addition of gaseous CO2 into a homogeneous mixture of gases acts solely to change the radiative-energy transport response of the mixture. The sole interactions between the energy and the gaseous mixture are radiative phenomena and processes. There’s nothing else in there.
3. Addition of CO2 into the Earth’s atmosphere will act to decrease the fraction of the incoming radiative energy supply that is returned back to deep space.
4. Some vague average temperature, over grand, but unspecified, temporal and spatial scales, of some part(s) of the Earth’s systems must increase so that the increase in the fraction of retained radiative energy input will be rejected back into deep space.
5. Feedback, primarily (almost exclusively) associated with water vapor, is assigned an important player with respect to the amount of temperature increase associated with the increase in the energy content of the Earth’s systems.
Note, especially, that the change in the radiative energy budget at the outer boundary of the Earth’s systems will highly likely never be subjected to validation. That is, the fundamental hypothesis of the AGW issue will highly likely not ever be validated.
Note, too, that for every hour of every day, some radiative energy is lost from the Earth’s systems back into deep space. The focus seems to always be, without exception, that the energy content of the Earth’s systems is increasing with time. It is not. The energy content of the Earth’s systems is constantly changing at all time and space scales.
Equilibrium:
I continue to fret over the fundamental hypotheses that have been presented to support the basis of the effects of increased concentrations of CO2 in the Earth’s systems. And, yes, I know this borders on heresy, but I’m an engineer and have a pretty good grasp of several aspects of energy transport, storage, exchange, and associated responses of materials.
I firstly get stuck at the radiative-equilibrium stage. Surely this equilibrium is not the rock-steady equilibrium as used in thermodynamics and other energy-budget and -balance situations. Equilibrium can generally mean different things within different contexts.
The first, within the context of energy budgets and balance, is that all materials that comprise the systems are at a uniform temperature at all spatial locations and for all time. There are no driving gradients in any potentials that could initiate change. Clearly this is not the equilibrium of interest whenever radiative-equilibrium and the Earth’s systems are the subject. Such a state has never been and will never be attained for these systems.
Secondly it can mean ’steady state’ or ’stationary state’; what comes out is equal to what goes in. I think this is the meaning for radiative-equilibrium. However, so far as I know the statement cannot be held to mean the same degree of equality that is generally associated with the concept of equilibrium. The radiative-energy exchange for the Earth’s systems is always changing at all temporal and spatial scales. What goes out is seldom, if ever, equal to what comes in.
There are no inherent natural physical phenomena and processes acting so as to produce such a response by the Earth’s systems. None of the natural phenomena and processes can possibly be ensuring that as the period of time over which in-come=out-go is theoretically to obtain, say, “Whoa, we need some corrections here because in-come is not equal to out-go.” All the subsystems, both internally and between systems ring as a function of time. There are no over-damped mechanisms that ensure monotonic approach to a state of equality for in-come and out-go over any spatial or temporal scales. The radiative-energy transport phenomena and processes for all components of the systems vary in both space and time.
Thirdly the phrase can refer to some kind of quasi-equilibrium condition in which departures from a nearly-equilibrium state are small. I think maybe this is the condition whenever radiative-equilibirium of the Earth’s energy budget is the subject. The question now is, What have been the magnitudes, and the temporal and spatial scales, of these departures from an equilibrium state in the past.
The Problem
The thermal state of the Earth’s systems have always rang and will always ring. The significant heterogeneous nature of the thermodynamic states of the systems, in both space and time, plus the extremely wide range of time scales for the important phenomena and processes, ensures this response. Again, true equilibrium is a condition never experienced by the Earth’s systems, so we’re here talking about ringing on top of ringing. Some of the past departures from a more-or-less equilibrium state can be traced to known perturbations on either the in-coming and out-going energy, or both. Some of these perturbations occur at very long intervals as determined primarily by the mechanics of the Earth-Sun system.
There are no inherent natural physical phenomena and processes acting so as to maintain the present state of the radiative-energy balance. Natural events, both external from and internal to, the Earth’s systems are free to cause changes in the state of the systems that can either increase or decrease the amount of energy that reaches the important parts of the Earth’s systems; in-come. Natural events can also act to both increase or decrease the amount of energy leaving the systems; out-go. Very likely, the grand-time-and-space-average albedo is changing all the time and thus changing the in-coming energy. So are the mechanisms that effect loss of infrared energy and changes in the out-going energy.
The estimates of the Earth’s energy-balance state that we see frequently published in the peer-reviewed literature are based on the assumption that the Earth’s systems are currently at an equilibrium state for energy in-come and out-go. This is nothing more than an un-tested hypothesis. A hypothesis that will very likely never be validated by measured data. I have yet to see any of these include accounting of the uncertainties in any of the numerical values used in the arithmetic. And there are uncertainties; none of the numerical values are known with certainties. To make the numbers add to zero when it is clear that the systems are not in equilibrium, is simply wrong.
So, it seems to me that to discern the effects of human activities on the radiative-energy equilibrium balance, we need to determine the delta ( increase or decrease ) in energy content, not from some unattainable equilibrium state, and not from the long-time-scale perturbations in a quasi-equilibrium state, and not from the natural perturbations, but from the perturbations of these latter states.
This is a very confusing description. Let’s try the following. Draw a horizontal line to represent the unattainable equilibrium state. Superimpose along this line the long-time-scales perturbations due to Earth-Sun orbital mechanics. Superimpose on this latter curve the perturbations due to natural variations in the radiative-energy transport properties and characteristics of the systems. And, finally, the effects of human activities are superimposed on this last curve.
Unfortunately, we don’t know the time scales for all the perturbations, so we don’t know which is which. However, some might be better understood than others. Additionally, if we restrict criteria and metrics to planet-wide averages, we don’t know the spatial extent of perturbations that might be of sufficient magnitude to affect the over-all energy balance.
It’s a very tough problem, in my opinion.
OK
For clarity…
The assertion is not that increased C02 causes Global Warming
The assertion is that increased C02 causes ‘warming’, immeasurable currently.
Andrew
49, Dan Hughes. Wow, lots to think about there. Thanks!
Jeff Id said
April 20, 2010 at 11:24 am
#44 You have my point correctly, the post is intended to convince people that
there is a central bit of information in warming which cannot be reasonably denied.
Andrew_KY said
April 20, 2010 at 12:18 pm
#50 immeasurable currently.
Steve Fitzpatrick said
April 20, 2010 at 8:55 am
#40 You have also seen posts on this thread and several other threads at TAV by practicing scientists in a number of other fields, all in agreement with the basics of radiative physics. This really is not something on which there is any scientific disagreement.
BUT I have not seen an answer to why physicists at a molecular level say CO2 has a high specific heat capacity,
and chemists using their mass in a mixed atmosphere equations say CO2 has a low specific heat capacity.
re Space – it’s temperature neutral, where there is nothing there is no temperature.
– but let’s leave “big bang” out of this.
Kevoika said
This question is one plank of the “how much warming does CO2 cause?” platform. What are the factors that the GCM’s – like MODTRAN use for this?
MODTRAN aint a GCM. its not a global circulation model. I’ll do a crude explanation of MODTRAN. You start out with a HITRAN database. That’s a database of aborbtion by the molecule type
http://www.cfa.harvard.edu/hitran/
read that site.
HITRAN is always being updated. If we start emitting some new substance into the atmosphere, that will eventually
make it into HITRAN. The data is both observed and calculated:
“The parameters in HITRAN are sometimes direct observations, but often calculated. These calculations are the result of various quantum-mechanical solutions. The goal of HITRAN is to have a theoretically self-consistent set of parameters, while at the same time attempting to maximize the accuracy. References for the source are included for the most important parameters on each line of the database. ”
The HITRAN database is then used in programs ( radiative transfer codes), like MODTRAN. There are more sophicated codes
than MODTRAN, like line by line codes, but we will stick with MODTRAN just cause you asked about it.
Now lets suppose that you want to know how radiation will TRANSFER through a “medium”. Why would you want to know that. Lets take some simple examples. Suppose you want to predict how an IR signal will attenuate as it travels through a medium. If you are in the airforce you want to know this for very important reasons. If you have a sensor in space looking at the earth, you want to know what can you see. If you put a source on the ground and look at it from space, what do you SEE? Modtran and codes like it describe what you will see. You will see that energy gets aborbed/transmitted/ reflected.
RTE’s describe how this works. if C02 did not reflect/transmit/absorb in the way that RTEs predict, none of our airbourne, space bourne, land based sensor systems WOULD WORK. period.
http://www.modtran.org/features/index.html
So when a denialist blathers on about the trace gas argument or throw ice in the air or any other one of these types of arguments, they are denying a working functioning “verified” piece of science.
It’s doubly ironic because when someone argues that H02 is a great absorber of IR, then are actually appealing to the physics of RTE. Further, If you are familiar with Lidzen’s iris argument it boils down to this: there are transmission windows
where, according to the laws of RTE physics, the radiation can get out.
http://earthobservatory.nasa.gov/Features/Iris/
These types of arguments dont DENY radiative physics, they DEPEND upon them. Even Brego’s argument DEPENDS upon RTE being a valid way of computing the transmission of radiation through the atmosphere.
What we dont know as well: feedbacks:
Dan Hughes said
“Addition of CO2 into the Earth’s systems has a potential to decrease the out-going long-wave radiation. We do not yet know that this has in fact occurred.”
Recently I ran across the following comments on a blog. The comments are followed by my response.
1. “The physics of the direct warming effects of increased concentrations of CO2 and other infrared-absorbing gasses is completely clear.”
Let me try, “The physics of radiative-energy transport phenomena and processes given changing compositions of CO2 and other infrared-absorbing gasses in a homogeneous mixture of gases is completely clear.”
In fact, I think this can be expanded to include all radiative-energy transport phenomena and processes, ( absorption, transmission, and reflectance ), for both ultra-violet and infrared radiation, so long as homogeneous mixtures of gases are the material.”
Thanks Dan.
To put it in a nutshell for readers: you accept the physics of RTE. What happens to the climate as a WHOLE, is a different question. But if you have a column of air and you want to describe/predict/ how energy will be transmitted/reflected/absorbed by that column, you rely on RTE. It gives you the right answer for that question. full stop.
My point is this. We can make little headway in discussions as long as some people wont accept the basic physics of this this well specified condition. that is, if some people disbelieve the science that describes the simplest condition ( transmission through a vertical column, with all the attendant assumptions ) then there is no way to even talk about the global case, where some of these assumptions are varying.
Josh Keeler:
“Whether or not CO2 increasing makes a measurable difference, or causes more negative or positive feedbacks, or what percentage of the net increases that have been observed we are directly responsible for, is where the debate should be waged, not on the fundamental physics of how a CO2 molecule absorbs radiation, which is something that can be clearly demonstrated in a lab.”
PRECISELY. here is my advice for denialists. You can accept RTE and still be a skeptic. In fact you will throw the warmists a huge curveball by simply stating that you believe in RTE. basically it takes away the “anti science” argument from their
retorts.
Steve F
” Certainly above the troposphere, there are very few clouds (ice), no liquid water, and very little vapor.”
Brego left in a huff before that could be explained to him. But it did give me a chance to do some fun reading on ice in the troposphere and a neat paper on how radiation effects crystal growth.
#55 Yes.
Trying to deny that RTE is real and understood and accurately represents the forcing caused by a rise in CO2 ppm is just silly. Its like trying to deny that my morning coffee has a certain heat content, and that if I drink it, I will be heated by that amount.
On the other hand, it don’t follow from the fact that there is a forcing of a given amount that the temperature will rise by any particular amount. As you can see from the fact that it don’t follow from the fact that I’ve absorbed a given amount of heat that my temperature will rise by any particular amount.
When people then start arguing, if you doubt Warming, you must doubt the basic physics of RTE, this is completely fallacious. It is similar to arguing, if you doubt that the coffee will cause your temp to rise, you must be doubting the heat content of the coffee, which is perfectly well known physics.
No, in both cases, we know what the heat input is. What is not certain is what effect it has on the system.
The takeaway for skeptics:
“The purpose of this post is to show skeptics that they don’t need to fear the radiative physics in order to make the same points. It’s probably my first post where I actually attempted to focus the debate to what limited means I can. All of your other points are fine and work just the same whether CO2 captures outgoing radiation or not.”
basically this. If you deny RTE you are denying something YOU DONT NEED TO DENY. and by denying it, you just look wrong or silly or uniformed, to the skeptics who use RTE every day of their working lives. you give the other side AN EASY TARGET.
it allows the other side to argue that ‘all skeptics” are anti science. Give up your bad arguments. It’s like the warmists arguing that “hide the decline” was a standard accepted method.
54, Mosher:
“My point is this. We can make little headway in discussions as long as some people wont accept the basic physics of this this well specified condition. that is, if some people disbelieve the science that describes the simplest condition ( transmission through a vertical column, with all the attendant assumptions ) then there is no way to even talk about the global case, where some of these assumptions are varying.”
Fair enough. And we can make little headway in discussions as long as some people won’t also consider the effects of thermalization and convection. That radiative energy drives these phenomena, also.
And believers can throw a curve-ball by saying “we believe that the magnitude of cloud feedback is uncertain” taking away the “political” angle and everybody can smoke the peace pipe 🙂
Well, I’m not going to waste any more time repeating the same old explanation again, but I still find it astonishing that after 20 years of the greenhouse effect being ‘the most important issue facing mankind’, the vast majority of people don’t have the foggiest how it works. Nowhere in your explanation do you mention convection, or lapse rates, even though they are essential to an understanding of the effect in a real atmosphere.
Yes, radiative physics means CO2 will absorb outgoing radiation. And then convection will completely annihilate any temperature change before it can occur. Excess heat cannot build up near the surface, because any gas so heated immediately rises up and away from the surface.
Yes, radiative physics is perfectly true. No, it does not imply any warming.
It is the logical step from one to the other that you keep missing. Proving only the first part does not achieve anything.
The warming is caused by a completely different mechanism, that you’ll find in the technical literature, but that everybody else seems determinedly blind to.
#61 That’s just frustrating. Please read the post and comments carefully. I make no argument which disagrees with your rant in any way shape or form.
#49 — excellent post, Dan, thanks. I don’t understand how so many well trained people come to think that radiation physics is an adequate theory of climate response.
You can’t create warming, just transform energy and transfer heat.
I am more an adept of the “decrease cooling” than “increase warming”, it fits better my physical understanding of the process and incidentally, I find people more receptive to this approach (I don’t know why, I can only only wild conjectures)
“Incoming light goes right through the CO2, outgoing light get’s absorbed and re-emitted.”
but in my limited understanding you only described half of the argument in your post (or two third: earth surface emits, CO2 etc absorb). I ll appreciate if you could show the emission spectrum of CO2, H2O, CH4 and so on in atmospheric conditions.
#63, I hope you understand that I don’t hold radiation theory to describe response, just that it exists and it works.
“I always want somebody that doesn’t think CO2 is GHG to explain why the surface of the Earth is 33°C or so warmer than it would be without the GHGs. How does that work out in a universe where GHGs don’t exist?”
I will be interested in those numbers calculated taking into account the oceans 😉
#64, The average of the gasses follows the Planck blackbody. This again is a separate issue. Really, it’s a bit frustrating that people refuse to disaggregate the point that heatflow is retarded from the actual response of the climate to the retarded heatflow.
Pat Frank:
Just as I have trouble with people who deny that radiative physics exists and is understood. Jeff’s point of course.
Climate is more complex than just CO2, I know few reasonable AGW types who say otherwise. Actually it’s the detractors who try and simplify the theory, usually as a prelude to try and tear it down.
JAE #43:
On my comment:
“..How can the outgoing longwave radiation from the top of the atmosphere be only (about) 240 W/m^2 while the upward longwave radiation from the surface be 396 W/m^2?”
Said:
“Most radiation to space doesn’t come directly from the surface; it comes from the air rather high in the troposphere. Maybe 255 K is about the averate temperature of that air? I don’t think you really need a “geenhouse effect” to explain this. MAYBE it explains it; maybe not.”
Exactly right in the first part. The radiation to space is, on average, from a temperature of 255K which is quite high in the troposphere.
However, if you look at a graph of outgoing radiation you will see that wavelengths around 15um match a Planck curve around 220K, while others match quite a higher temperature. You can see this in the 3rd graphic in The Earth’s Energy Budget – Part Three
What is this telling us? That some wavelengths are radiated from lower in the atmosphere (warmer) and some from higher (colder). This is because at some wavelengths the atmosphere absorbs much more strongly and, therefore, re-emits at this higher location = colder temperature.
Convection determines the temperature profile in the troposphere. It’s not an alternative theory. It’s part of the same theory.
But suppose there was no atmospheric absorption and re-emission of longwave radiation. Would we still see the same effect?
Even if we still had a convective profile we would see very different surface temperatures..
The radiation would be from the surface of the earth. If there was no absorption in the atmosphere the radiation from the surface of the earth would equal the radiation from the top of atmosphere. (It can’t vanish).
Right now, this year, that would be 396 W/m^2 from the surface = 396 W/m^2 from the top of atmosphere. But only about 240 W/m^2 is absorbed from solar radiation. So the earth would cool down (at a rate depending on the heat capacity of the oceans and how will mixed they are) until finally 240 W/m^2 was the radiation from the surface. This would be a temperature of 255K.
“..We do know that a real greenhouse works only because convection is blocked..”
The world agrees. That’s why I always put the term in “”. No climate science is based on equating the climate with a greenhouse.
“..I would sure like to find a way to test the falsifiability of this theory.”
Take a little while to understand it and you will see how to falsify it.
Let’s consider CO2, a strong absorber at 15um:
– Theory says that the atmosphere will absorb strongly in 15um band (and says exactly how much when the radiative transfer equations are calculated) – therefore we should see radiation to space from a much higher colder temperature in this band compared with say 10-14um.
— We do.
– Theory says that the atmosphere will radiate in all directions, therefore we should see much higher radiation from 15um band downwards at the earth’s surface, compared with 10-14um.
— We do. See CO2 – An Insignificant Trace Gas? Part Six – Visualization
On another blog someone suggested the reason for the downward longwave radiation was reflection. We can falsify that theory because if that was the case we wouldn’t see the downward radiation concentrated in 15um (CO2), 9.6um (ozone) etc.
A clarification on #69.
The concept of more absorption meaning radiation from higher in the atmosphere might need explanation for many.. A more detailed explanation can be found at The Earth’s Energy Budget – Part Three
A quick explanation here – many people who’ve read about the inappropriately-named “greenhouse” effect understand that various trace gases absorb energy. A missing understanding for many is that these trace gases also re-emit energy.
Many people think of longwave radiation and CO2 at 15um as something like a torch shining through sand. Once you have enough sand – nothing gets through. Right?
It’s not the right mental picture.
A trace gas like CO2 absorbs energy from a photon and collides with neighboring molecules – so that whole layer of the atmosphere heats up. This layer of the atmosphere radiates in all directions according to its temperature and emissivity (some gases like N2 can’t radiate at these wavelengths and some can, each with specific wavelengths at which they can radiate). Therefore radiation isn’t being “stopped”, it just keeps getting re-emitted.
So wavelengths which are very strongly absorbed can’t radiate from the surface out to space. The more strongly a wavelength is absorbed the higher up it will radiate from – because it has been absorbed and re-emitted many times, from each successive “layer” in the atmosphere. (There aren’t “layers” in the atmosphere, it’s continuous, just trying to help with a mental picture).
I think we can all agree that temperature is a measure of the intensity of molecular motion. Heat causes molecules to increase motion (translational, rotational, vibrational), and the temperature goes up.
Now, picture a single CO2 molecule that receives an IR photon at a frequency that is allowed. The molecule gains motion and is “hotter.” This molecule will then very quickly either lose a photon at some allowed frequency or, MUCH MORE OFTEN, it will collide with a neighboring molecule in the air. Such collisions will usually impart part of the CO2 molecule’s energy to the other molecule. This is the process of THERMALIZATION, and it is how 97% of the atmosphere (N2 and O2) are energized (heated) EACH DAY. Greenhouse gases are very important in warming the atmosphere in that they can absorb the IR, whereas N2 and O2 cannot (much). Of course, they are also critical in radiating heat to space, thereby cooling the atmosphere.
But I have this issue: Once the CO2 molecule gives up its energy to a neighboring molecule, or loses it by firing off a photon, IT HAS LOST ENERGY. IT IS NOW “COLDER AND SLOWER,” AND IT CANNOT RADIATE (at least at some frequencies) until it gets another photon or collides with another molecule. Of course, it will quickly become “warmer” by collision or by receiving more thermal radiation, and the process is repeated. Gradually the whole air column warms—from the surface upward in accordance with the lapse rate.
But the point here is that at any given time, a large majority of the CO2 molecules are “colder” than many surrounding molecules. It seems to me that the notion that all the GHG molecules are little space heaters that are constantly radiating is wrong. I don’t know what this means, relative to the presumed greenhouse effect, but I do know that most of the energy that is received from the sun each day goes into heating ALL the molecules in the air column, most of that heat being near the surface. The GHGs are doing lots of “jobs,” not just radiating full time. Their “main job” has to be thermalization, or else the atmosphere could not warm uniformly!
AND there is only so much energy from the Sun. In the subtropical deserts in summer, about 3.96 E+7 joules/m2 is received at the surface (11 kw-hr). This is enough to warm the first 5 km of atmosphere by an average of about 6 C every day (assuming an average heat capacity of the air of 1 joule/gram/K). And, indeed, that is close to what we see.
That heat is then lost at night, and the process repeats itself, day after day. There really is no need to invoke a “backradiation” meme, but maybe it also contributes to the system.
#65, I see that, Jeff, but some of what you write leaves me confused about what you really think. I agree that radiation physics works, and have nothing but respect for physical theory. RP would be the perfect theory for an irradiated planet with a transparent atmosphere of N2, O2, and CO2, with no hydrology, no phase changes, and no clouds. Not Earth. 🙂
Re: steven mosher (Apr 20 14:11),
Hear, hear!
I’ve been trying to make this point for years. Why attack the warmers on the physics fundamentals where they are strongest? The really flaky parts of the IPCC AR’s are the SRES and the Working Group II and III chapters. Even if the models were correct, the data they use to project comes from the SRES, which are mostly a really bad joke. GIGO. As for WGII and WGIII, look at the audit of peer reviewed references. The fraction decreases a lot in WGII from WGI and is even less in WGIII. But for policy purposes, WGII and WGKII are the most important chapters as they deal with the effects and costs.
#62, I did read it carefully. There are three steps. CO2 absorbs radiation. This retards heatflow. This causes the observed climate warming/dangerous future warming. You have been careful to separate stages 2 and 3 (rightly!), but you continue to conflate 1 and 2.
#67 “Really, it’s a bit frustrating that people refuse to disaggregate the point that heatflow is retarded from the actual response of the climate to the retarded heatflow.”
But you haven’t shown retarded heatflow. You’ve shown absorption of radiation by CO2. The two are different.
#69, “But suppose there was no atmospheric absorption and re-emission of longwave radiation. Would we still see the same effect?”
I gave a toy example of a greenhouse effect working with absolutely no atmospheric absorption and re-emission of longwave radiation over at your site. I forget exactly where – I’ll have a look for it when I have some more time. It worked by absorption of shortwave by high-level clouds – which were transparent to the longwave from the surface. It’s only emission of longwave that matters, not absorption.
“The world agrees.” Apart from NASA. “Certain gases in the atmosphere behave like the glass on a greenhouse, allowing sunlight to enter, but blocking heat from escaping.” (See also their bit on Venus.)
My point is that the explanations most people are exposed to do not set out the correct physics. People watch Al Gore’s movie, argue with it, and then you come along and switch Al Gore’s explanation for Ramanathan’s and then complain about how they have totally misunderstood. Others do the same, but with far less politeness. Of course they’ve misunderstood! Nobody has ever explained it properly to them!
Re: Geoff Sherrington (Apr 20 08:05),
You need to be more specific. Infinitely thick at what wavelength? What’s the emission spectrum of your light source? Is the CO2 isothermal or is there a temperature gradient. Is the temperature of the CO2 maintained by an external source or not? Let’s take a narrow bandwidth source at 15 micrometers and an isothermal, finite volume of CO2. If the brightness temperature of the source is less than the temperature of the CO2 and there is no other source of thermal energy, the CO2 will cool until its emission balances the absorption. The converse is also true.
re 73:
The really flaky parts of the IPCC AR’s are the SRES
Yup. I think on day one of my entry into this mess I looked into the SRES and had to laugh.
Re: Nullius in Verba (Apr 20 15:51),
Convection moves heat around, it doesn’t annihilate it. Your statement seems to imply that the surface can’t warm, but the atmosphere above the surface can. If the upper atmosphere warms, convection is reduced not increased. The reason that net convective transfer (latent plus sensible heat) from the surface is larger than the net radiative transfer is because the pure radiative lapse rate is larger than the adiabatic lapse rate. So radiation forces convection. Also the physics of the water vapor/liquid phase change makes convection more efficient. To put it another way, if the atmosphere warms, so will the surface.
75 DeWitt Payne & 38 Nick Stokes,
My question in 37 was purposely loaded. Whereas there are physical equations for processes such as specific heat of transformation from one phase to another of a nominated material, there are no laws that cover the CO2 scenario I posed, for reasons that DeWitt lists, and more – I posted similarly recently on Niche Modeling, noting that a CO2 doubling on different assumptions in the atmosphere could lead to stasis, heat increase or heat decrease.
The solution that Nick proposes does not have the status of a “law”; it is a compound model of fair complexity.
That is where those coming from one direction are not meeting up with those coming from another. Typically concise and neat, standard thermodynamics seems to be across a gap from observational modelling with its unusual coefficients and powers and a general messiness.
That said, it surprises me still that the demon CO2 cannot be hitched to heat production via a couple of simple equations. If it can’t be done routinely in the lab, how can we infer it for the rather more complex environment of the atmosphere? While first principles indicate that light absorption by CO2 produces heat, the process cannot be separated in Nature from the destinations and interaction mechanisms of that heat. Which is another way to say the science is not settled.
JAE said
April 20, 2010 at 10:24 pm
“I think we can all agree that temperature is a measure of the intensity of molecular motion. Heat causes molecules to increase motion (translational, rotational, vibrational), and the temperature goes up.”
Well, the devil is in the details. The thermal energy of a gas is mostly translational motion, but a molecule of CO2 that absorbs infrared light at ~4.3 microns goes to an excited vibrational state where the carbon-oxygen bonds are stretching and contracting like a spring.. this is not the same as a more rapid translational speed which would be associated with higher temperature. Absorption of CO2 at 14 microns causes the molecule to go to an excited vibrational state where the carbon-oxygen bonds bend back and forth from the normal linear oxygen-carbon-oxygen alignment.
The excited state can certainly be ‘quenched’ by impact with another molecule (which will cause heating via conversion of the vibrational energy to translational energy), but how fast this happens (and the probability of quenching versus a randomly oriented re-emission at the original wavelength) depends on the gas density. The probability of quenching (if I remember right) goes roughly as the square of the atmospheric pressure. So high in the atmosphere a lot of re-emission takes place with much less conversion to sensible heat.
Missed the timing of the post and have not read all the comments.
I will not enter into a discussion about what some people believe is the physics but let me point out a few things that may cause a little more thought on the subject.
Jeff’s figure 1 is old. It maybe be exaggerated. For CO2 look at figure 4. There is no absorption of radiant energy at a wavelength greater than 16 micron. Both figures 1 & 4 refer to 100% CO2 and show the absorption wavelengths for CO2 too wide. Have a look at the NIST (National Institute of Standards & Technology) database http://webbook.nist.gov/cgi/cbook.cgi?ID=C124389&Mask=200 and I think this is the spectra http://webbook.nist.gov/cgi/cbook.cgi?ID=C124389&Type=IR-SPEC&Index=0#IR-SPEC It will be seen a) that absorption at 4.2 micron is very very narrow. I believe that it is distinct and is used to identify CO2 on other planets b) the absorption band between 14 and 16 micron is like the normal probability curve with a peak absorption of 70% (not 100%). The latter band is also occurs in the H20 vapor spectra. I understand from some article including discussion on updates of the HITRAN database. The many past measurements have been contaminated by water vapor and that new missing lines have been found for water vapor.
You many have noted in the past comments on some websites about the self cooking chicken in the microwave. Regardless of the actual mechanism of radiation absorption and re-emission energy can not be created from nothing.
There are two questions the radiant absorption by CO2 a) how much does it absorb and b) what amount is transferred to other molecules to heat the surrounds.
The first question requires two calculations which both have assumptions. Firstly, there is an energy balance
For temperature calculations only the net heat transfer counts. If there are two molecules of CO2 in container with 100% reflecting surrounds at the same temperature, there will be no heat transfer between them and their temperature will not change. There can be no heat transfer from a cool (negative degree C) troposphere to a higher temperature earth surface. If 170 W/m2 are received at the surface then a similar amount (with variations from time to time of surface absorption particularly the oceans and re-emission)must leave the surface. But at the surface there is heat transfer by convection (surely everyone has sen heat hases, mirages, willi-willis, eagles and other birds gliding on up-draughts etc). Books on heat transfer and my own many calculations have found a split of something like 50:50 on land between radiation and convection. Then there is evaporation of water over seas & oceans. (I have seen no paper in which anyone actually calculates these values or even mentions Nusselt,Prandtl,or Reynolds numbers)
Then one can make a calculation of the absorptivity of CO2 using for example the Hottel (5-145 in Perry’s Chemical Engineering Handbook) which includes partial pressures, temperature of source and receiver, beam length, the wavelength emissivities. I used and assumption of a beam length of 11 km (some only use 8km atmospheric height). I came up with an overall absorptivity for CO2 of 0.007 and for H2O vapor of 0.4 on a clear day. Then considering over laps and total heat flow. My assessment is that CO2 has a negligible effect on heat absorption. (I have seen no climate-related paper which makes the slightest mention of Prof Hoyt Hottel an recognised world expert on heat transfer by radiation)
Finally, there is the second question. People have made guesses at that. The AGW people seem to say CO2 does not radiate to space.
There are others (including John T Houghton in “The Physics of the Atmosphere) that say CO2 radiates a lot to space. If CO2 re-radiates all its absorbed energy then there will be no increase in temperature. Maybe it is somewhere between.
In the end actual measurements, properly separated into various components, has be be correct. The evidence (from icecores proxies and more recently measurement by varies accurate instruments) indicates that temperature leads CO2. This can be explained if CO2 as a negligible effect on atmospheric temperatures. The evidence can not be explained if it “guessed/assumed” that doubling of CO2 will cause measurable temperature increases of 1 to 3.5 degrees C
Re: Steve Fitzpatrick (Apr 21 04:43),
For CO2, that’s very high. I found some references the other day that showed that for at least some transitions of CO2, local thermal equilibrium applied to above 90 km. LTE means that collisional transfer is much more probable than emission and the Boltzmann energy distribution is still valid. Kirchhoff’s Law only applies if LTE is true, btw. For other gases, non-LTE correction becomes important above about 30 km.
Re: Cement a friend (Apr 21 04:47),
There are too many errors in your post to even attempt to address. I suggest you obtain a copy of a textbook on atmospheric radiative transfer and read it. I can personally recommend A First Course in Atmospheric Radiation by Grant W. Petty (only $36 direct from the publisher). You might also want to learn some Physical Meteorology, lapse rates in particular. Actually, Caballero’s section on radiative transfer is fairly good too. There’s also lots of good stuff on a somewhat less technical level at The Science of Doom.
Wow, posts and comments like these sure are are interesting to this amateur! Steve M, your “translations” for the lay people are also much appreciated.
#77,
“Convection moves heat around, it doesn’t annihilate it.”
Agreed. Which is why I specifically said temperature change, not heat.
‘Annihilate’ was probably the wrong word. I meant ‘stop it from happening’.
“If the upper atmosphere warms, convection is reduced not increased.”
True, but that comes later. Excess potential temperature at the surface leads to more convection, leading to an equalisation of potential temperature, leading to less convection.
“The reason that net convective transfer (latent plus sensible heat) from the surface is larger than the net radiative transfer is because the pure radiative lapse rate is larger than the adiabatic lapse rate.”
Absolutely! Brilliant! That’s exactly my point! Thank you!
When the radiative lapse rate is larger than the adiabatic lapse rate, it is the adiabatic lapse rate that controls the temperature profile, including the surface temperature. Which means you’ve got to talk about the adiabatic lapse rate if you want to explain the average surface temperature and changes therein, you can’t talk purely about radiation.
I want to be clear. I’m not saying that CO2 doesn’t cause surface warming, because it does. I’m not saying anything unorthodox or cranky, because this stuff is straight out of the atmospheric physics textbooks. I’m saying that the radiative explanation given is not the correct description of how/why this warming takes place.
The greenhouse effect in a convective atmosphere depends on the energy input, the average altitude of upward emission of longwave from the atmosphere direct to space, and the lapse rate between this altitude and the surface.
There is another version of the greenhouse effect in a non-convective atmosphere (the n-shells model – I discussed it over at scienceofdoom), to which all the radiative explanations people have been giving apply. In a non-convective atmosphere, you’d all be right.
But in the real atmosphere, convective coupling ties the vertical temperature profile of the entire troposphere together. In any one place, the whole thing heats or cools together, so that as a whole it emits to space what it receives from the sun and by horizontal transfer. Radiation internal to the atmosphere can only make a difference when the adiabatic condition is not met, as happens when convection stops. Otherwise, the adiabatic lapse rate completely dominates radiation, and it is lapse rate that is in control.
Re: Nullius in Verba (Apr 21 14:04),
The n-shells model is a simplification used to calculate changes in radiative transfer based on changes in ghg concentrations. The temperature profile is fixed for a given location (Tropical, midlatitude summer and winter, subarctic summer and winter and 1976 standard atmosphere for MODTRAN) so convective heat transfer is, in fact, built in. Obviously this breaks down for very large changes. However, 1D radiative/convective models end up producing a vertical temperature profile very similar to the measured profile whether you start with an isothermal atmosphere cooler than the surface or warmer than the surface. That supports the use of a fixed lapse rate assumption in the RT n-shell models like MODTRAN. The fact that calculated spectra, not to mention imaging calculations, match observation very well is also a good indication that the n-shells model for RT calculation is basically correct. 3D GCM’s also include convection. That’s the C part. I don’t think they do it right, but they don’t ignore it.
DeWitt Payne,
The n-shells model is also a simplification in which convective transfer is ignored, and you simply consider n blackbody shells around the Earth. See RealClimate or the discussion I referred you to.
It’s unfortunate that there seems to be no uniform terminology for these different models.
Nullius: Thanks; your “model” answers my questions about the purely radiative models.
Re: Nullius in Verba (Apr 21 17:06),
Ah, I see now. You’re talking about something like Willis Eschenbach’s Steel Greenhouse. Everyone, including Willis, (well apparently not you) realizes that it’s a toy model for demonstrating the concept and not meant to be a real representation of the Earth’s atmosphere. The IR spectrum of the atmosphere is complex and far from a gray body with constant emissivity/absorptivity. But a toy n-shell model is useful for demonstrating how you can get surface warming without violating the Second Law.
This may be a stupid question, but I’m not a scientist and having a difficult time understanding how an excited molecule can collide with another molecule creating more heat. Where is the energy being expended from to create the heat resulting from the collision thereby warming the atmosphere from multiple collisions?
Also, I was reading one of Willie Soon’s papers and he shows over a city (Salt Lake City UT?) with large cyclical fluctuations in CO2 levels there is no temperature signal following these cycles.
Thanks
89, DG: Your instincts are correct, no heat is created, some is just transferred during the collisions.
“Also, I was reading one of Willie Soon’s papers and he shows over a city (Salt Lake City UT?) with large cyclical fluctuations in CO2 levels there is no temperature signal following these cycles.”
This kind of observation bugs me, too, but there may be so many things that are varying that the effect can’t be seen.
Steve Mosher,
Thanks for the explanation and catching the MODTRAN – CGM goof. I slipped up when I used that term – I intended to say radiation models.
I have looked at the HITRAN DB (especially oxygen for fun), and played with MODTRAN. I also understand that small amounts of CO2 can play a large role in the infrared spectrum. CO2 lasers work due to it.
Yes, overall the issue is feedback and to date all I hear about are positive feedbacks (H2O is argued both ways). Must be negative one(s) somewhere or CO2 at 2000ppm in the past would have negated my existence.
Re: DG (Apr 21 19:26),
It’s about conversion of energy from one form to another. A photon can be thought of as a packet of energy. The amount of energy is proportional to the frequency or inversely proportional to the wavelength. When a photon is absorbed by a molecule, the energy of the molecule increases by the amount of energy in the photon. For CO2, absorption of a 15 micrometer photon causes the molecule to start vibrating by bending. If you think of a CO2 molecule as three balls connected by springs, grab the center ball and shake it back and forth. The outer two balls, the oxygen atoms, will vibrate. However, the velocity of the molecule and the resulting kinetic energy doesn’t change much. The vibrating molecule can emit another photon and stop vibrating or it can collide with another molecule and the energy of the vibration can be converted to kinetic energy. That is, the velocity of one or both of the molecules increases and the vibration stops. Temperature is a measure of the total kinetic energy of the system. The absorption of photons and the conversion of the photon energy to kinetic energy increases the temperature of the system. A collision can also cause a CO2 molecule to start vibrating and emit a photon. That collision is inelastic and the velocities and total kinetic energy of the colliding molecules decreases. The fraction of CO2 molecules in an excited state increases with temperature and can be calculated from the energy of the excited state, its degeneracy and the temperature. For the bending mode of CO2, the degeneracy is 2 because the vibration can be perpendicular or parallel to a plane through the molecule. The spectrum has many lines because the molecule is rotating and there are very many rotational energy levels. Emission or absorption of a photon can change the rotational as well as the vibrational energy level. An excess of absorption over emission warms the system and an excess of emission cools the system. The width of a given line is also important and is a function of temperature and pressure. That has important consequences but I won’t go into that now.
#88,
“Everyone, including Willis, (well apparently not you) realizes that it’s a toy model for demonstrating the concept and not meant to be a real representation of the Earth’s atmosphere.”
Why is nobody reading what I write? Of course I realise it’s a toy model, and not real. That’s what I’ve been saying. My point is that this is the model that all of you are talking about when you speak of heat being ‘trapped’, of the greenhouse effect being caused by the absorption and downward re-emission of longwave. They’re all true statements of the toy example. They’re not true statements of a real convective/adiabatic atmosphere.
When Jeff plots graphs showing “outgoing light get’s absorbed and re-emitted” by CO2 and talks about “the retarded heatflow” that results, he is giving a description of how the toy model works. And apparently not even realising that he’s doing it.
You have said yourself that when the radiative lapse rate exceeds the adiabatic lapse rate, the adiabatic one rules. Not the radiative one. The adiabatic pressure effect completely takes over. The radiative causes of the radiative lapse rate at the surface – i.e. trapped/downwelling radiation – no longer has any effect, because you are in an adiabatic regime. The explanation is related to outward-looking effects towards the top of the atmosphere, and only connected to the surface by the adiabatic lapse rate.
Sigh. I always do this. I promise myself not to get dragged in again, and then somebody says something that makes me think they’ve nearly got it, and I get dragged in again.
I apologise for getting frustrated and annoying you all.
“Why is nobody reading what I write?”
I’m reading it. 🙂
JAE,
Thank you. It is seriously appreciated.
I don’t mind people disbelieving. I’d like it (sort of) if people were able to prove me wrong. But it’s terribly frustrating to get the impression that people are misunderstanding what I’m trying to say. I keep on wanting to explain a bit more, say it again a different way. Outright rejection would be less tantalising. But to have people repeat back what you’re trying to say as a proof that you’re wrong…
Oh, well. Another time, maybe.
Glad I could help.
Nullis:
If it helps your mood any, I generally agree with you on this, but a couple of points:
1) I’m not sure there’s not some subtleties related to the role that radiative transfer plays in “ordinary” thermal conduction for a gas (I’m thinking absorption and reemission here). E.g., see this.
2) Also the “real” lapse rate is not the adiabatic one (typically it’s around 6.5K/km versus roughly 10K/km for the adiabatic case), so the top of the atmosphere is not connected to the the surface simply “by the adiabatic lapse rate”.
DeWitt: Your turn, even though you pretend not to “see” me. LOL.
NV: You still don’t get a pass, because you have not demonstrated WITH EMPIRICAL EVIDENCE that you are correct.
91 Carrick
It would be nice to see the full paper you indicate in point 1. It seems from what is there that the paper may not be correct about thermal conductivity. Perry’s Chemical Engineering Handbook has a lot of data, in addition there are formulae for calculating values for most gases at different temperatures and pressures (see page 2-368 for examples for CO2). However, it is good to see a paper that uses dimensionless numbers.
Re: Nullius in Verba (Apr 22 13:33),
The dominance of convection in determining the temperature profile in the troposphere doesn’t make radiative transfer go away. Increase the CO2 concentration and the surface sees more radiation from the atmosphere. MODTRAN calculation: 1976 standard atmosphere, 0 km, looking up, all other settings default
280 ppmv CO2 257.323 W/m2
560 ppmv CO2 260.526 W/m2
All other things being equal (which is the point of this post), that will increase the temperature of the surface and the temperature at all altitudes in the troposphere. MODTRAN isn’t a toy model. It’s results have been validated against observations in the real world.
Re: DeWitt Payne (Apr 23 10:22),
I didn’t bother to calculate it, but the emission from the top of the atmosphere also goes down when CO2 goes up. Since radiative emission is proportional to the brightness temperature through the Stefan Boltzmann equation (yes, I know it’s not exact when emissivity isn’t constant but it’s still a good approximation), the temperature at the top of the atmosphere goes down while it goes up at the bottom. That’s effectively equivalent to decreasing the thermal conductivity of the atmosphere. So saying that adding CO2 retards heat flow is not incorrect.
Please show me quantitatively rather than simply by assertion how convection will prevent this from happening. Miskolczi is not acceptable, btw. Remember that the temperature at the bottom of the atmosphere is closely coupled to the surface temperature. Any warming of the lower atmosphere will increase the amount of IR radiation seen by the surface.
Jeff, I am a skeptic. I know that CO2 holds some heat which adds to the Earth’s warmth a little bit. A little bit because it is a trace gas. I also know that doubling the amount of CO2 doe not double its ability to hold heat. And then you have the fact that the atmosphere is not a closed system.
I also know that the geologic past shows no indication of tipping points where the Earth’s climate spins out of control and everything burns to a crisp! Okay, a bit of exaggeration, but that is one of the main reasons why I say that with the evidence we have that shows absolutely nothing in the way of warming (and I say that because the signal is well within the error bands) that AGW is bunk, a fraud, much ado about nothing, etc. It just doesn’t matter except as a method to steal billions of dollars from us.
It has no other purpose. And any further research you do on it is simply to fulfill your own curiosity – which is fine. But the AGW matter is proven as bunk.
Nullias in Verba – I read your comment and I agree with you. Thank you.
#96 (2) Good point. I skipped that for simplicity’s sake. If anybody wants to know more, they might want to look up what ‘MALR’ stands for.
#98, Agreed. This is a long way from being an answer. I’m just trying to get people to ask the right questions.
#100, “The dominance of convection in determining the temperature profile in the troposphere doesn’t make radiative transfer go away.”
Absolutely agree. Never said it did.
I said radiative transfer didn’t control the surface temperature. I said that in a convecting atmosphere back radiation wouldn’t cause the surface temperature to rise. I didn’t say radiative transfer didn’t happen.
“All other things being equal (which is the point of this post)”
I’m not entirely sure what that means. Do you mean that convection from the surface doesn’t change, even though the surface is being heated by this extra radiation in excess of the air above it?
“that will increase the temperature of the surface and the temperature at all altitudes in the troposphere”
You are transferring heat from one part of the troposphere to another. The total heat in the troposphere is not changed by such an internal transaction – so if you think the heat from the upper atmosphere will radiate to warm the surface, and this will rise to warm the atmosphere that has just emitted the heat in question above its initial temperature… well, I’m sorry, but that looks to me like a very neat perpetual motion machine.
Maybe you meant something else?
#101, “I didn’t bother to calculate it, but the emission from the top of the atmosphere also goes down when CO2 goes up.”
Depends what you’re holding fixed. Taking the time-averaged equilibrium, the total power in equals the total power out, and the Earth as a whole can only lose energy by radiation to space. Thus, under these assumptions (and constant albedo, etc.), the emission from the top of the atmosphere always stays the same.
It can of course vary temporarily under non-equilibrium conditions. But I’m trying to keep things simple.
“the temperature at the top of the atmosphere goes down while it goes up at the bottom. That’s effectively equivalent to decreasing the thermal conductivity of the atmosphere.”
That’s also equivalent to changing the adiabatic lapse rate.
Now that would be a counter-argument. If you can tell me why increasing CO2 concentration would change the adiabatic lapse rate because of this internal radiative transfer (as opposed to water vapour feedback), then that would show me where I was going wrong. Does it?
You were saying earlier that the adiabatic lapse rate replaces the radiative lapse rate, but now you say the adiabatic lapse rate varies with the radiative one. What does that mean? By how much? Do you have any references for the theory behind this?
And how does it fit in with “that will increase the temperature […] at all altitudes in the troposphere”?
(PS. It occurred to me in passing that you might be talking about the stratosphere as “the top of the atmosphere” – there’s a different set of answers to that.)
(PPS. I’m well aware that Miskolczi is bunk – due to invalid use of an inapplicable form of the Virial theorem. You need have no worries on that score.)
So, as many of you have already pointed out, CO2 absorbs 15um photons and converts this to kinetic energy of gases in the air. If CO2 is heating the air with IR-radiation (which otherwise could leave our climate system at the speed of light) and warm air radiates blackbody spectrum according to it’s temperature, as any other body, right? If yes, then CO2 effectively converts narrow-band (15um) energy to wide-band blackbody radiation and does not create additional warming. But air temp near the ground (first 10 meters? some number like this was in the article from Heinz Hug on John Daly’s page) will be slightly higher and cooling is somewhat less rapid. But this can be called additional warming only if we consider statistical flat-earth with average insolation around day and night, just like in Trenberth et al 1997 or 2009, real planet starts cooling after sun sets and cools asymptotically to some “equilibrium” value and CO2 just delays this cooling somewhat, and if I understand this correctly, final temperature does not depend (at least at our CO2 concentrations) much on this delay, unlike summer nights with large air humidity.
Is this correct?
If yes, there seems to be no problem at all with the endangered species in the WGII.
DeWitt,
You might also be interested in answering JAE’s Phoenix/Atlanta question. Here’s my suggestion, for reference.
Hempster: As I understand: It’s more complicated. While the surface approaches a blackbody, air does not, since the emissions from it (IR) occur only at those frequencies “allowed” by CO2 and HOH (e.g., the band centering on 15 microns that you mentioned). The bulk of the air (about 97% N2 and O2)can’t absorb/emit in the IR (with very minor exceptions). All the absorption and emission “work” has to be done by the “greenhouse gases.” They also have to absorb IR and “share” it with the O2 and N2 by collisions. That is the real reason the GHGs are so important. There appear to be an over-abundance of GHGs, allowing quick and complete thermalization of the air.
103, Nullius:
“(PPS. I’m well aware that Miskolczi is bunk – due to invalid use of an inapplicable form of the Virial theorem. You need have no worries on that score.)”
I think Miskolczi is using the term “viral theorm” loosely (and wrongly) to explain a relationship he has found. He has taken a lot of heat on this, and I don’t know if he’s ever completely defended himself–I lost touch and interest.
Nullius: In re-reading your responses about “my question,” I’m not sure if you addressed the whole enchalada. I am not only intrigued about the temperature difference in these locations (which you addressed), but with the concept of backradiation. If I understand the GHG backradiation stuff correctly, there should be about 4 times as much of it in Atlanta as in Phoenix on a nice clear July day, due to the higher amount of water vapor in atlanta. If this is true, then a greenhouse made of an IR transparent material should get much hotter in Atlanta than in Phoenix (the inside would receive both solar radiation AND all that backradiation). I doubt that it does, but of course I haven’t done the experiment.
JAE, do you really think it’s only possible for gases to radiate at characteristic wavelengths and not by inelastic collisions where colliding particles lose enough kinetic energy for radiating a photon? Or, with other words – how minor are the “very minor exceptions”?
My main point was about CO2 induced delay in cooling after sunset, I think it’s somewhat analogous to adding a capacitor to electronic circuit – it will delay signals but definitely will not increase the total energy in the circuit. So, if this analogy is even close to be correct, CO2 does not create warming, but it does warm the air and by this slows convective cooling of the ground, which in Trenberth et al flat-earth world translates to “warming.”
Hempster: You are going above my level of expertise; so rather than speculate (and get hollered at 🙂 ), I’ll let those with more expertise answer.
“104 – But this can be called additional warming only if we consider statistical flat-earth with average insolation around day and night,”
Hempster – FWIW this concerns me too. But I haven’t yet done the number crunching and thinking to get to the bottom of it – assuming I could!; having seen the Reader Profile thread I’m guessing there are others here who can do this in their sleep before I’ve figured out where to start.
To SMA I visualise the earth’s surface temperature as an elastic temp. surface that is around the rotating planet. As the planet turns within it the surface will be typically extended along the vector from centre of earth to centre of the sun with distortions according to the many factors touched on above. Total deformation of this surface from a reference position is IMO what the global mean surface temp anomaly is trying to quantify. I haven’t done the numbers but if CO2 is the biggie here I’d expect this anomaly to change monatonically to reflect the (apparently) ever increasing effect of CO2. The fact we get spikes and jumps on short timescales says (to me) something is wrong with this – where has the energy gone from one year to the next and how does if reappear again? My first reaction is the metric is not good enough for diagnostic utility, second is the model of CO2 providing a known constant and quantifiable system forcing is not correct, third other forcings are not understood, fourth the interelationships of potential forcings is not understood. Any/all of these IMO are possible, nothing new and I haven’t got the depth of understanding of many here. It is also possible that the temp. surface has a shape characteristic which changes with time – this would equate to regional climate changes that maybe independent/uncorrelated of/to global changes.
Back to the the visualisation; from a given point on the earth’s surface this is of a pulsating envelope passing over with daily and hourly variations in all directions. So what is the elasticity of this surface? IMO it’s the various heat transport mechanisms to shift energy around. How we quantify how large an area they act over and which ones are active at any one time I think is (at least in part) a function of the actual geography at each location on the planet (land/sea flat/mountainous desert/rainforest etc). So the temp. surface will respond IMO differently according to the orientation of the earth within it. Given I’m visualising this as a dynamic system I’m wondering what analogies might help? I’m already out of my depth but things like bubble envelopes rising in fluids come to mind which I’m guessing must be some sort of quasi constant energy surface subject to dynamic disturbances. These are the type of things that make me think chaos is the appropriate line of investigation but caveat that I know squat.
Apologies for the half (quarter?) baked nature of the above – I’m breaking the golden no blogging after the pub rule and most of the above is on my list of things to try to bottom out. DeWitt, Carrick and co please set me straight! If nothing else, hope it makes you grin and apologies if all this is available at science of doom/elsewhere – I haven’t had time to get stuck in to the info. over there! And apologies for the ambiguous use of surface – if it wasn’t post pub I’d rephrase consistently with “envelope” to keep things distinct 🙂
#108. I haven’t done the numbers, but yes, I would think you would be getting more back radiation in Atlanta. Just as you get more back radiation on a cloudy as opposed to a clear night.
As for the experiment with the greenhouse, I assume you’re aware of professor RW Wood’s 1909 experiment with IR transparent/opaque greenhouses? I make no comment about the professor’s speculations, but the experimental result is interesting.
I realise that isn’t an answer, but another question. Or rather, another set of questions. But then I’ve always thought the questions were more important.
112: Yes, I’m aware of Wood’s findings. Maybe I can get some of that oil money–or maybe even stimulus money–to do some experiments. If you follow the temperatures and humidities at a given location, there is absolutely no correlation between them. That’s another reason I think you are right about convection being the controlling mechanism (rather than backradiation schemes).
112, 113: Forgot to specify that the correlation between temperature and humidity is lacking WHEN IT IS CLEAR (you pick the location). If water vapor added to the temperature, via backradiation, it should generally be hotter when it is humid than when it is dry. This is evidently not the case. Because convection rules?
Re: Nullius in Verba (Apr 23 14:45),
No, it isn’t. The surface sees a higher brightness temperature from the air above it, so it loses less heat and the temperature goes up. The temperature of the air column above it also goes up and the final temperature profile has the same slope as the original, but is offset to a higher level at all altitudes. Because the temperature at all altitudes is higher, the heat content of the atmosphere is also higher. If you move additional heat from the surface to a higher altitude, it increases the heat content at that altitude and the temperature goes up from what it was before.
I can do the steel greenhouse with convection if you want. Absent the trivial cases of infinite conductivity, the surface will still be warmer than the shell. For infinite thermal conductivity, the atmosphere would be isothermal. Since it’s not, we can rule that possibility out. Zero thermal conductivity can also be ruled out as it would produce the radiative only lapse rate which is much higher than observed. We’ll also assume for the toy model that the atmosphere is completely transparent to IR radiation.
So lets say that some fraction of transfer of heat from the surface to the shell will be by convection/conduction rather than radiation, but blackbody radiative physics still applies. We have a very large sphere (so we can use a parallel plate approximation) with an internal heat source that produces a surface flux of 240 W/m2 surrounded by a shell with an emissivity/absorptivity of 1. At equilibrium, the shell must radiate 240 W/m2 outward so it has a temperature of 255 K. Then the surface of the sphere sees 240 W/m2 from the 255 K shell and receives 240 W/m2 from the interior. If half the heat flow to the shell is by conduction/convection from the surface then the surface must radiate an additional 120 W/m2 and has a temperature of 282 K and the temperature difference is 27 K for a thermal conductivity of 240/27 or 8.89 W/K m2. Assuming a linear decrease in temperature with altitude and constant pressure, the average temperature of the atmosphere is 268.5 K.
So what happens if the internal heat source is increased to 244 W/m2? If the proportion of heat transferred by convection remains constant, then the surface must radiate 366 W/m2 and 122 W/m2 will be carried by convection. The shell temperature will be 256 K and the surface temperature will be 283.4 K and the temperature difference would be 27.4 K for a thermal conductivity of 8.91 W/m2 K or about the same. A more reasonable approach would be to keep the thermal conductivity constant, but that won’t change the numbers much. The average temperature of the atmosphere will be 269.7, up 1.2 K, which means the heat content of the atmosphere must increase. But wait, suppose that, magically, all the additional heat from both the interior and the shell is transferred by convection so the surface temperature remains constant. The means the surface will still be 282 K, and the shell will still be 256 K, so the average temperature of the atmosphere will still go up to 269 K from 268.5 K. Which means the heat content of the atmosphere still goes up, just not as much. But what about the thermal conductivity? That’s 244/26 or 9.38 W/m2 K. In order to keep the surface temperature constant for an increase in forcing, the thermal conductivity must increase substantially. How is that supposed to happen, other than by magic?
Is there a profile of atmospheric CO2 concentration by altitude? The lapse rate of CO2 as it were. I think it makes somewhat of a difference on exactly where in the atmosphere that the a CO2 molecule actually absorbs/re-emits its photons and transfers heat by radiation. In the low pressure of the upper atmosphere, an excited (hotter) CO2 molecule has fewer opportunities to radiate its heat to other molecules. A re-emitted photon also stands a better chance of getting back out to space. An atmospheric layer of a given thickness and CO2 and other GHG density should behave according to the partial reflection of IR. Some number of photons pass through the layer unabsorbed, some number are absorbed and re-emitted, the re-emitted photons being reflected in a manner consistent with the sum of the Feynman arrows, and difference in energy of re-emitted photons versus that absorbed being measure of energy transfer to the reflective media itself (the CO2/H20/Methane, etc.) which will then operate under the principles of radiative transfer. Am I wrong-footing this by saying that you must deal with partial reflection before getting to radiative transfer?
DeWitt Payne said in Post 115
April 26, 2010 at 1:16 am
Re: Nullius in Verba (Apr 23 14:45),
” I can do the steel greenhouse with convection if you want. ”
Presumably trying to convey that you had dealt with another first… You didn’t.
” The surface sees a higher brightness temperature from the air above it, ”
What ?
Anyway as your all talking / relying on radiative physics, how about this piece,
http://greenhouse.geologist-1011.net/
Tidied pdf version also available from climate realists dot com,
Click to access The%20Greenhouse%20Effect%20Origins%20Falsification%20%20Replacement%20by%20Timothy%20Casey3.pdf
An excerpt from the pdf regarding global energy budgets that seem to be the preferred diagramtic explanation of the effects of the supposedly settled and seemingly demanded not to be argued with “radiative physics” of CO2 and other so called “greenhouse gases”…
” In the overall picture, for the “greenhouse gases” to radiate 324 Wm-2 towards the ground,
they must equally radiate 324 Wm-2 into space which turns the earth into a heat creation machine
emitting 666 Wm-2 for a total absorption of 342 Wm-2. ”
and,
” If absorbed radiation in a translucent body is counted against total incoming radiation to get absorptivity,
temperatures calculated from this value will be grossly exaggerated because
transmitted radiation does not contribute to heat congestion nor to the temperature of the material through which it is transmitted
– and yet this is part of the sum that totals to the amount of incoming radiation.
Therefore absorptivity is equal to absorption divided by the sum of absorption and reflection.
In the example by Kiehl and Trenberth (1997) above, this amounts to an atmospheric absorptivity (emissivity) of 87 / (77 + 87) = 0.5305.
From this emissivity determination and the 214 Wm-2 that must be radiated from atmosphere,
the Stefan-Boltzmann Equation yields 290ºK or 17ºC as a mean global surface temperature. ”
and,
” However, we need to throw away the energy recycling mechanism,
as you cannot spend and store the same energy at the same time,
or you wind up with a mechanism that violates the First Law of Thermodynamics by creating energy.
This said, the corrected “Back Radiation” for Kiehl & Trenberth (1997) is
214/2 = 107 Wm-2 (the half of the atmospheric radiation that is not directed towards space)
– a far cry from Kiehl and Trenberth’s 324 Wm-2. ”
and,
” In fact, version 2.0 of the Greenhouse effect neglects any quantitative science at all.
There is no measurable thermodynamic property used to compare the relative strengths of greenhouse gases, and
there is no equation of measurable thermodynamic properties that likewise can give us
an indication of how much one gas is more a greenhouse gas than another.
The measured “emissivities” of gases we have to date are not applicable because
they are intended for use in systems where the point radiation is unknown.
In fact, no gas emissivities applicable to calculating temperature from radiative emission have been measured.
We may well be able to determine air emissivity from remote imaging systems at the present time, but
we have nothing on the component gases. It is impossible to do more than guess at how CO2
from combustion and additionally from other sources such as respiration, deflation (soil erosion) and volcanic activity;
affect the bulk thermal emissivity of the atmosphere as a consequence of compositional change, and temperature.
The science isn’t settled at all. In fact as it turns out,
nobody even bothered to collect the evidence. ”
But there sure are plenty around who like to argue otherwise,
even though their emperor HAS NO CLOTHES.
Re: hswiseman (Apr 26 10:44),
The absolute amount of CO2 in a given volume decreases with altitude so the optical depth at any given wavelength also decreases. The concentration varies somewhat with altitude. The cyan line in this graph is the concentration profile used by MODTRAN for the 1976 standard atmosphere calculations. Peak emission to space happens at the altitude where the optical depth is about 1. For the center of the 15 micrometer CO2 band, that’s about 10 km and is very close to the tropopause.
Re: hswiseman (Apr 26 10:44),
Probably. It isn’t really reflection, with the exception of high altitude cirrus ice clouds where there is significant reflectivity for a small part of the thermal IR region. An individual CO2 molecule usually doesn’t emit a photon after absorption. The energy is transferred to other molecules by inelastic collision and some other CO2 molecule is excited by an inelastic collision and emits a photon in a random direction.
117, Derek:
WOW, what an interesting paper! JeffID should put it up for discussion.
DeWitt Payne said in Post 119
April 26, 2010 at 11:44 am
” The absolute amount of CO2 in a given volume decreases with altitude so the optical depth at any given wavelength also decreases.
The concentration varies somewhat with altitude. T
he cyan line in this graph is the concentration profile used by MODTRAN for the 1976 standard atmosphere calculations.
Peak emission to space happens at the altitude where the optical depth is about 1.
For the center of the 15 micrometer CO2 band, that’s about 10 km and is very close to the tropopause. ”
Some graph, I’d like to see the actual H2O water vapour, AND liguid AND soild water figures.
Seems surprising such a heavy molecule as CO2 is so evenly distributed throughout the depth of the atmosphere does it not.
(Isn’t CO2 washed out of the atmosphere by rain…)
That does not seem to apply to the other molecules either ?
Oh, and by the way, liquid water has an emission peak at 15 micrometres. As Brego has mentioned here before,
I’ve repeated his post at GWS, with the plots he gives from Segelstein 1981 MS thesis.
http://www.globalwarmingskeptics.info/forums/thread-655.html
Is all the 15 micronmetre radiation from CO2, no, but you have not mentioned that.
The graph you have given does not mention water (liquid, or solid) either, BOTH are in the atmosphere.
On the climaterealist blog I posted the following
Posted by cementafriend (forum) on Apr 25th 2010, 10:37 PM EDT
I must read the full article a bit more closely but it is the first article I have seen in hundreds on climate assessment that mentions the measurements of heat transfer on combustion gases (including CO2) made by the late Prof Hottel of MIT. His entry on Wikipedia is here http://en.wikipedia.org/wiki/Hoyt_C._Hottel . Hottel wrote the section “Heat Transfer by radiation” in Perry’s Chemical engineering Handbook pages 5-23 to 5-42. In that, there is an equation based on measurements that allows the calculation of CO2 and H2O absorptivity from inputs of temperature, partial pressures and beam length. Other books on heat transfer have the Hottel equation in a graphical form.
In considerations of heat transfer it will be noted that net heat flux only occurs from a higher energy source to a lower energy receiver. This has been measured over one hundred years in the operation of heat exchangers, boilers, furnaces etc. The Trenberth and Kiehl paper on Global heat balance is wrong in assuming that a cold atmosphere radiates back to a warm earth surface.
Posted by Alan Siddons (forum) on Apr 25th 2010, 10:58 PM EDT
“net heat flux only occurs from a higher energy source to a lower energy receiver. This has been measured over one hundred years in the operation of heat exchangers, boilers, furnaces etc. The Trenberth and Kiehl paper on global heat balance is wrong in assuming that a cold atmosphere radiates back to a warm earth surface.”
Well said, cementafriend. Or, as professor M. Quinn Brewster puts it in his book Thermal Radiative Transfer and Properties, “Like conduction, thermal energy is in harmony with the second law of thermodynamics such that, in the absence of work, thermal energy is radiated spontaneously from higher temperature to lower temperature matter.” Now to get the rest of the climate community to admit that.
I am sorry De Witt I prefer information based on measurements. I have made hundreds of heat balances in heat exchangers and furnaces backed by measurements. I have designed and modified burners (for coal, oil, natural gas and waste fuels)to improve heat transfer. Heat transfer, thermodynamics, fluid dynamics, evaporation, psychrometry, prediction and correlation of physical properties, process measurement and control, investment and profitability are all chemical engineering subjects which are involved in climate assessment. No doubt you know your narrow subject very well but does it have relevance to the wider subjects of heat transfer and thermodynamics?
Sorry everyone I should have mentioned that I was referring to the article mentioned by Derek 117, and JAE 120 above.
cheers, I hope everyone is well and those in northern parts are not experiencing the proverbial “brass monkey” weather
122, Cement: Yes, NET heat flux is from warmer to cooler, but there is still RADIATION from cooler to warmer. The issue is whether that means anything. According to the paper linked in 117, the conventional concepts are all wrong. I would like to see this paper discussed.
Re: Cement a friend (Apr 26 21:16),
Now tell me again that the temperature of the lower temperature sink does not affect the NET heat transfer rate. The equation for black body radiation for plane parallel sources at T1 and T2 is E=0.0000000567*(T1^4-T2^4). Each plane MUST radiate at the black body rate, which is unaffected by the presence or absence of a nearby object. But the NET heat transfer depends entirely on the difference in temperature.
Did you never notice that a clear night is usually colder than a cloudy night? The cloud cover does not warm the surface, it reduces the rate of cooling because the (brightness) temperature of the cloud layer is higher than the temperature of clear sky. There is no Second Law violation. Buy a simple IR thermometer from an auto parts or kitchen supply store. If it’s not too cold, you can actually measure the temperature of the sky and the ground at night and prove to yourself that clouds are warmer than clear sky for a given surface temperature.
JAE 124 I have reservations about your comment. I have seen measurement on electrical cables showing no current when the voltage at both ends is the same. I have made measurements with heat pipes showing no heat flux by conduction between bodies at the same temperature. Maybe you could point me to a measurement of light flux in an optical cable between two source of light of the same intensity and wavelength.
I would conjecture that if there are two molecules of say CO2 at the same temperature each would be saturated at the 15 micron wavelength so no energy could pass between them.
With a hot surface radiating would that not swamp all incoming radiation at the same wavelength from a colder surface? Was not the jamming of radio signals in war time based on the principle of high intensity radio wave emission?
DeWitt 125 I have no argument with you about Clouds reducing the rate of heat loss at night. I experience that regularly.
My concern is with the Kiehl & Trenberth papers. There are plenty who also disagree with the back radiation and assume that the net fluxes from the surface by radiation (after convection and evaporation) is 66 W/m2 eg fig 2 of Murellis at physicsworld.com PhysicsWorld.com (May 2003 The climatic effects of water vapor -I hope the link works)
keep well
Looks like the link did not work maybe this time http://physicsworld.com/cws/article/print/17402
Re: Cement a friend (Apr 27 11:02),
The net transfer by radiation from the surface is indeed ~66 W/m2 and the rest is sensible (24 W/m2) and latent (78 W/m2) heat transfer by convection. But those are exactly the same numbers in the Kiehl and Trenberth cartoon. The problem is that you have to account for surface temperature and resulting blackbody radiation for a complete energy balance. At an average temperature of 288 K (T1 in the equation above) the surface radiates 390 W/m2. For the net heat flow to be 66 W/m2, then the atmosphere has to radiate 324 W/m2 toward the surface (390-324=66) for an average brightness temperature of 275 K (T2) or 0.0000000567*(288^4-275^4)=66. The actual brightness temperature of the sky is of course higher for cloudy sky and lower for clear sky. A gross surface emission rate of 66 W/m2 corresponds to a temperature of 185 K. IIRC, a temperature that low has only been measured at the South Pole.
Folks, the radiation balance cartoons are absurd. Take the case of the tropics, where the ocean temperatures are around 28 C all the time. This temperature supports continuous radiation FROM THE SURFACE of about 270 Wm-2. Now, if you add even the average “backradiation” of 324 watts used in the cartoons to this (it should actually be much higher than this in the tropics), you get 570 Wm-2, which is equivalent to a blackbody at 46 C (319 K). It never gets anywhere near that hot in the tropics over water.
Hi DeWitt
I hope you can tolerate a little more naivety. When I speak of partial reflection I am referring to the QED phenomena which determines how many photons at a given wavelength pass through the medium and how many are essentially turned away at the gate. The sky is blue because the medium (the atmosphere) lets a lot of blue wavelength photons through relative to other wavelength photons. If CO2 molecules are absorbing IR photons and generally not re-emitting a photon, the net number of IR photons making it through to earth should be reduced with increasing CO2 concentration. The absorption of the IR photon increases the kinetic energy of the molecule which then behaves according to radiative physics. If the photons absorbed by a CO2 molecule exceed the loss of kinetic energy by radiation, I imagine the molecule will experience an elevation in electron shell state until reaching the maximum shell level, with the absorption of the next photon resulting in the emission of a photon and drop of electron shell state. The energy level of the emitted photon should equal the difference in energy between shell x and shell x-1 (electron shell states can change only by whole number). The wavelength of the emitted photon would be greater than that of the absorbed photon because it takes several photons of absorbed IR to elevate shell levels, but only one photon dispenses the molecular energy of the drop in shell state (white hot instead of red hot) I think this is what is mean’t when folks talk about saturation of the spectral band, at least with respect to this particular molecule. (Jeff, if this is arrant nonsense, please delete and spare me the embarrassment. LOL)
Hswiseman: IR doesn’t affect electrons. It just causes vibration, stretching and translational motions.
#131, I’m not excited by the article myself. I am impressed by others opinions of it so may be missing something. If someone with skill wrote a short summary and link in .doc format, I’ll make it a post. As it is, my time is very limited.
Re: hswiseman (Apr 27 17:31),
What makes the sky blue is scattering. That’s basically an elastic collision of a photon with an atom or molecule. Scattering efficiency is inversely proportional to wavelength, thus blue sky and red sun when seen through a long path of haze at sunset or sunrise. IR photons don’t scatter much from molecules.
Multiple photon absorption is very unlikely. The large number of lines in, for example, the 15 micrometer CO2 band comes from the interaction of vibration and rotation. The molecule only goes up one level from the ground state for vibration, but there are many rotational levels that can be occupied in both the ground and first excited vibrational state as well as two degenerate first excited states (in plane and out of plane vibration). You get different photon energies because the transition back from the excited state to the ground state is not necessarily to the same rotational state. The same goes for excitation to the first excited state from a ground state. Because the rotational levels are so close together, all of them will be populated to some degree in the ground state.
132: I may have a go at it, if I have time. There are quite a few physicists who don’t accept the “conventional wisdom,” so it is very possible that something is missing.
#134, Time is what you make.
135: The bottom line is that there is absolutely no emiprical evidence for the “atmospheric greenhouse effect” that DeWitt Pain is trying to sell here and what IPCC dogma is totally based upon. That is why I’m so interested in the paper linked in 117. If the following quote is accurate, then the whole AGW physical house of cards collapses:
“…and so, if the magical conversion of light rays into dark rays was really happening, the interior of Wood’s diathermic greenhouse would have been significantly colder than that of Wood’s glass greenhouse. The fact that both performed equally proves that visible light is not converted into heat on absorption. Wood (1909) provides experimental (and thus scientific) facts that soundly disprove the greenhouse effect by disproving the mechanism. Moreover, the Wood Experiment soundly falsifies the later Greenhouse warming mechanism based on increasing the role of an upper atmosphere heat relay by increasing upper atmosphere absorbtivity. If anything, the first stage of Wood’s experiment showed that increasing upper atmosphere infrared absorbtion would have a cooling effect on the lower atmosphere. This is explained by the division of relayed infrared radiation between that relayed towards the graound and the equal amount relayed straight back out into space.”
AND:
“The hypothesis proposed by Arrhenius (1896, 1906) that visible light is converted to heat on absorbtion and thence re-emitted as infrared can be tested using lasers in the visible spectrum and rapid response black fluid distillation thermometers.
Modern equipment, such as a laser pen (532nm at 5mW over a 3mm diameter), a clothes peg, and 2x Stevenson-Reeves calibrated distillation thermometers (black fluid), and a hand lens (10x), is more than sufficient to testing Arrhenius’ hypothetical core mechanism of the Greenhouse Effect (IE that visible radiation is converted into infrared radiation when absorbed and re-emitted). The beam of the laser pen has a total radiation of:
(0.005) / (0.0015 x 0.0015 x 3.1416) = 0.005 / (7.07 x 10-6) = 707 Wm-2.
Shining a laser like this into the eye could cause serious injury and I’ve observed that even reflection scatter from the beam is intense enough to cause severe headaches if exposure is sufficient. When playing with lasers, please take care. That said, 700 Wm-2 is much more intense than sunlight (at sea level), and eminently suitable for testing Arrhenius’ wavelength shifting Greenhouse mechanism.
The method is to place the thermometers side by side, parallel but separated by one centimetre (about half an inch), with the graduations lined up. Affix the laser at least thirty centimeters (about one foot) away from the thermometers, so that when switched on, the beam strikes and is centred on the base of one thermometer. Prior to switching on the laser, use the hand lens to verify that both thermometers are indicating an equal temperature (to the nearest 10th of a degree Celcius). Once the thermometers are thus equilibrated, use the clothes peg to fasten down the laser pen switch and keep the laser shining on the test thermometer. Having ensured that the laser is still centred on the base of the test thermometer, use the hand lens to occasionally compare tmeperatures of test and control thermometers. You will have observed that nearly all of the visible light is absorbed by the liquid of the test thermometer, but do you observe any variation in temperature between the thermometers?
The results I observed when I conducted this experiment over a period of about 30 minutes, offered no confirmation of Arrhenius’ wavelength shift. I observed no difference between the test thermometer with an additional 700 Wm-2 of visible light shining on the bulb and the control thermometer with no additional light shining on the bulb (other than ambient laboratory conditions equal for both thermometers). Even switching to a 630-670nm red laser affected no difference in temperatures indicated by test and control thermometers.
My conclusion is that increasing visible radiation, even by quite a large amount, results in no measurable rise in temperature because no appreciable amount of visible radiation is converted into infrared when absorbed and re-emitted – contrary to Arrhenius’ hypothesis. I further propose that infrared ratiation, hypothetically emitted by the fluid of the thermometer would at least in part be either reflected or absorbed by the glass, thereby raising the temperature of the thermometer fluid and causing the fluid to expand. This is not observed and so we may conclude that light is not transmuted into heat on absorbtion.”
Here is the only attempt that I have seen (besides my simple stuff) to get at the EMPIRICAL EVIDENCE that is absolutely necessary to test the greenhouse gas theory (the “warmers” and even thoughtful physicists like one posting here (who no longer “sees” me) don’t seem to be bothered at all by the lack of empirical evidence, which shows that they need some more training about the scientific method 🙂
IS THIS PAPER COMPLETELY BOGUS, OR IS THE WHOLE RADIATION SCHEME WRONG?
It is critical that someone determines this, because if the paper is right, the house of cards comes down on the merits!
JAE:
Even though Jeff’s post was crystal clear, let me take a cut at it.
The so-called greenhouse effect is due to water and CO2 trapping of outgoing Long Wave IR. It was covered in Geology 1A (physical geology), 1B (historical geology), 5A/B (oceanography), 117A/B (hydrogeology). That’s just one small field. Every other major branch of science and engineering uses this physics in some form or another. Infra-red detectors are used commonly used to measure CO2 concentrations in vapors. They work by measuring how much IR at the prime CO2 bands is blocked by the CO2 in the vapor sample. Same exact physics as Jeff outlines in this post.
Without atmospheric adsorption (e.g., the greenhouse effect) trapping out-going long-wave infra-red, Earth would be like the Moon: Boiling Hot in day and beyond freezing at night. The main CO2 absorption bands are right in the middle of the peak outgoing long wave radiation from the planet surface (25%). Water vapor absorption bands surround the CO2 band and is responsible for 60% of the surface heat retention. The man-made CO2 calculates to be about +0.6K since pristine and +1.2K at doubling when we are all off to our reward. No big deal. My Grandkids are smart. Let them figure out how to deal with it.
I don’t understand the “paper” linked in 117. It sounds like shade-tree experimental results concluding that the long history of a very practical branch of theoretical and applied physics is wrong. That’s heading into Al Gore territory.
137, Howard:
“I don’t understand the “paper” linked in 117. It sounds like shade-tree experimental results concluding that the long history of a very practical branch of theoretical and applied physics is wrong. That’s heading into Al Gore territory.”
The POINT of my comment is, again, that there is absolutely NO empirical evidence for any “greenhouse effect” that you describe. It looks logical, but it is not proven, DESPITE the fact that it is taught in virtually all science textbooks, as you say. The PROBLEM is that without empirical evidence, it is only a hypothesis, and a true SCIENTIFIC textbook should SAY SO.
The reason I’m interested so much in the paper that I quoted is that it purports to provide empirical evidence that shows the hypothesis is WRONG. If you know anything at all about the greenhouse gas concepts you will recognize the importance of the Wood’s experiments that the guy discusses (Wood proved that real greenhouses work only by preventing convection–back in 1909 or so). If the experiments outlined above are valid, then you can burn all of those textbooks you mention.
Now the article that was linked MAY be complete baloney; all I’m doing is asking for confirmation. I’m not necessarily supporting him (but as you will see from my other comments, I see other empirical evidence that something is wrong with the conventional theory that you have so completely accepted).
BTW, the comparison of a dry moon, which has no atmosphere, and whose “day” is 28 Earth days, or so Planet Earth is just silly. I have long thought that the temperatures on Earth can easily be explained simply by heat retention, mainly by the oceans (because light can penetrate deeply). My hypothesis is really no less proven than the “greenhouse” one 🙂
Re: Howard (Apr 28 07:39),
That’s not quite true. The moon has large day/night temperature swings because the heat capacity of the surface is low and its rotation rate is much slower. Most of the Earth is covered with liquid water which has a very high heat capacity. The diurnal temperature range for most of the ocean is less than one degree. The contribution of CO2 to this is to help keep the temperature high enough that the water is in the liquid state. But even if the oceans froze over completely, the diurnal temperature range would not be as large as for the moon. The upper limit would be set by the melting point of the ice.
It’s interesting that the Kiehl/Trenberth’s papers have been mentioned in this thread. People rattle off the numbers that appear in figure 7 of KT97, but apparently no one’s really read these papers. These numbers vary depending on the cloud cover. That’s why KT97 tackles this question early in the paper.
There are three layers referenced: a low cloud layer between 1 and 2 km. with area coverage of 49%, a midlevel layer between 5 and 6 km. with area coverage of 6%, and a high level layer between 10 and 11 km. with area coverage of 20%. They combine these layers using a method referred to as “random overlap” and obtain an overall cloud cover of 62%. (I’ll describe why this is important in a moment.) I’m not sure what “random overlap” means, but I can obtain the same number using the Inclusion-Exclusion principle. There are a couple of methods to calculate the result using the “In-Ex principle.” One is to add the percentages, subtract the binary products of the percentages, and add the triple product. I prefer the simpler version of taking the complement of the product of the complements or (1 – (1 – 0.49)*(1 – 0.06)*(1 – 0.20)) = 0.61648. Both methods produce the same result as there are mathematically equivalent.
So figure 7 should contain a statement that says: “62% cloud cover assumed,” yet it doesn’t. Indeed we aren’t certain that such a statement is correct, because the authors are ambiguous on this point.
For example, in table 2 there are two columns: one labeled “Clear” and the other labeled “Cloudy.” The cloudy numbers appear in figure 7, so here cloudy means 62%, we guess. In table 4, we have two more columns with labels “Clear sky” and “Cloudy sky.” The “Cloudy sky” shortwave value appears in figure 7; therefore here “Cloudy sky” means 62% (maybe?).
My favorite step is the KT97’s calculation of the IR window value: “The estimate of the amount leaving via the atmospheric window is somewhat ad hoc. In the clear sky case, the radiation in the window amounts to 99 W/m^2, while in the cloudy case the amount decreases to 80 W/m^2, showing that there is considerable absorption and re-emission at wavelengths in the so-called window by clouds. The value assigned in Fig. 7 of 40 W/m^2 is simply 38% of the clear sky case, corresponding to the observed cloudiness of about 62%. This emphasizes that very little radiation is actually transmitted directly to space as though the atmosphere were transparent.”
So did you understand the calculation? I’ll walk you through the logic. If “Cloudy” means 62% (as it did previously in the paper) then the energy flux through the window should be 80 W/m^2. Instead they take 38% of the clear sky value. That means they are interpolating between 99 W/m^2 and 0 W/m^2. (Do you really believe that 0 W/m^2 is correct for the cloudy sky case?) That number is 37.62 W/m^2 or 38 W/m^2. Why do they round up to the nearest tens value? They didn’t do that elsewhere in the paper. Why is the 80 W/m^2 value mentioned? Shouldn’t they be interpolating between 99 W/m^2 and 80 W/m^2? In that case the window value is 87.22 W/m^2 or 87 W/m^2. So which is the correct value: 38 W/m^2, 40 W/m^2, 80 W/m^2, or 87 W/m^2? Why didn’t Trenberth’s new paper correct this? They just reuse 40 W/m^2 without any further comment.
A window value of 87 W/m^2 really throws a “monkey wrench” into the energy balance diagram. The updated paper worries about 0.9 W/m^2 which magically disappears into the ocean. Really? What about the sloppy IR window calculation? There’s far more error in that calculation.
Jim
I understand the moon is has longer days and low albedo. However, daytime shade temps are subzero because the heat transfer in a vacuum is due to radiation only. Also, in a vacuum (no atmosphere scenario of DeWitt), the boiling point of water approaches absolute zero, therefore all water boils away, there will be no oceans left, no groundwater, no glaciers.
This is a truly impossible situation to consider. The empirical proof of the “greenhouse” effect is the fact that we are having this lame discussion. It is the source of all life and magic in this world.
OK, nice talking to myself.
I put the follow post at Climate realist
“Paper by Timothy Casey
Postby cementafriend » Thu Apr 29, 2010 12:19 am
I am surprised at the few comments on the paper “The Greenhouse Effect, Falsification & Replacement” by Timothy Casey.
The historical information is interesting.
One point I note is that monochromatic emissivity and absorptivity are the same but the total emissivity and absorptivity integrated over wavelengths will be somewhat different when the temperature of the source and receiver are different. This particularly applies to a surface and gas mixture receiver such as the atmosphere.
Maybe some of the brighter people here would like to compare this with the paper by Maurellis http://physicsworld.com/cws/article/print/17402 . Maurellis has in Figure 2 that of 66 w/m2 radiation from the surface 40 w/m2 passes through a window (no absorptance) . I have plugged some figures (CO2 380ppm expressed as a partial pressure, a beam length of 11km etc) into the Hottel equation for calculating absorptivity and found (ignoring overlap) the absorptivity of H2O in the atmosphere was 0.40 and for CO2 was 0.007 which lines up with Maurellis’ window of about 39%.
It seems to me that the Kiehl and Trenberth of back radiation can not be justified as outlined by Casey.”
I should add that the absorption by CO2 in my calculation is less than 0.46 W/m2. Beside the overlap it is possible that the absorption bands are saturated as found by Dr Hug (on the John Daly site (http://www.john-daly.com/artifact.htm . That would reduce my calculated value. The question then arises how much of this is converted to heat and how much is radiated to space.
To my mind the effect of CO2 is very small
Re: Howard (Apr 28 14:45),
Yes, if the Earth were like the Moon, it would be like the Moon. But it’s not. The Earth has a much higher mass and therefore gravitational field and rotates faster. So it will have an atmosphere and all the water won’t boil off into space. Even if it were cold enough for the seas to freeze over and the atmosphere were completely transparent to thermal IR, the surface would still have a higher heat capacity than the moon and, because of the higher rotation rate, the surface temperature would vary much less than the moon over the course of a day. Even if you removed all the other gases, the atmosphere would consist of water vapor which would still be gravitationally bound.
Re: Jim Masterson (Apr 28 11:41),
You’re missing the fact that the surface temperature under cloud cover will be higher than surface exposed to clear sky because the brightness temperature seen by the ground is a lot higher for a cloudy sky than for a clear sky and that the cloud tops are colder than the surface under them. It all works out.
Re: Cement a friend (Apr 28 18:35),
Hug is completely wrong. Saturation combined with the atmospheric temperature gradient (lapse rate) is what makes CO2 such an effective ghg.
Hottel’s data was never meant to be used for non-isotropic conditions and very long path lengths. You do know that line width varies with both the local pressure and temperature? Better tools, like MODTRAN and line-by-line programs, have long superseded Hottel for atmospheric radiative transfer calculations. Your continued reliance on such an outmoded tool makes further correspondence on my part appear to be an exercise in futility.
DeWitt: We are talking past one another. I get what you are saying.
>>
140: DeWitt Payne
April 28, 2010 at 7:42 pm
You’re missing the fact that the surface temperature under cloud cover will be higher than surface exposed to clear sky because the brightness temperature seen by the ground is a lot higher for a cloudy sky than for a clear sky and that the cloud tops are colder than the surface under them. It all works out.
<<
I think you confused my post with someone else. I said nothing about temperature.
However, with a model that I have and keeping all other things equal, removing an additional 47 W/m^2 from the surface and sending it straight out to space will reduce the surface temperature by more than 15K.
It doesn't seem to work out, does it?
Jim
Kevin Trenberth is recently finding his sums don’t work out within radiative balance.
However he should relax,there is no such law in physics.
A much more realistic picture was given recently by Richard Lindzen.
“Evidence Suggests Man-Made Warming Greatly Exaggerated”
In the article Lindzen pointed out that radiative equilibrium is seldom observed.
People everyday experience temperature changes of 20 degrees or so and yet the IPCC gets alarmed at a rise of less than a degree in the past century.
This prompted me to do a simple calculation based on the planet having no radiative balance whatsoever.
This illustrates the sheer thermal inertia of the bulk of the planet.
I have used a very simple model of the Earth made of uniform material with reasonable conductivity
If the Earth absorbed all the Suns radiation that landed on it and absolutely no heat ever escaped.
How long would it take for the temperature to rise by 1 degree centigrade.
Formula used
Pxt =cm(temperature rise)
P=1367W/m2x(crosssectional area of Earth)
t =time in seconds
C = specific heat capacity = 1000 (you can tweak this number if you like)
m = Mass of Earth =6×10power24
When calculated it turns out to be 1080 years.
Re: Suibhne (Apr 29 14:01),
Puhleeze. Reasonable conductivity indeed. Your formula implies near superconductivity. If the thermal conductivity of the the planet were within many orders of magnitude of what you assume, then the core wouldn’t be liquid. There would be no volcanoes or continental drift. The deep ocean wouldn’t be much colder than the surface. There would be no variation in temperature during the day, etc., etc.
Let’s make the planet out of pure copper with a core temperature of 5,000 K. What would be the heat flux at the surface and resulting temperature in the absence of any external radiation or atmosphere? For a first cut, assume an insulated bar with 1 m2 surface area at each end and 6E6 m long. If the surface temperature is zero, then the heat flow is 400*5000/6E6. That’s 0.33 W. So the actual surface temperature would be 49 K. that’s not enough to make a difference in the heat flow calculation. So even if the planet were made of pure copper, the entire mass wouldn’t heat and cool at once, only a thin layer of the surface.
Re: Jim Masterson (Apr 28 21:25),
There is no additional 47 W/m2. The surface exposed to clear sky radiates 390 W/m2. ~100 W/m2 of that goes directly to space. The rest is absorbed by the atmosphere. For cloud covered sky, the surface still radiates 390 W/m2, but none of it goes directly to space because clouds have an absorptivity very close to 1 in the thermal IR. It’s nearly 1 in the near IR or did you never notice how much cooler it feels when the sun goes behind a cloud. So yes I do believe with good reason that no IR from the surface is transmitted directly through cloud cover. But the clear sky surface sees more solar radiation and less long wave radiation from the atmosphere than the cloud covered surface and conversely. The cloud tops, because they’re cooler, emit only ~50 (30/0.6) W/m2 directly to space and the rest is absorbed by the atmosphere above them. If you can’t see how that balances, you haven’t read the article carefully enough.
DeWitt Payne
The topic under consideration was does the CO2 greenhouse effect exist.
In particular is radiative equilibrium a law of Physics.
“I have used a very simple model of the Earth made of uniform material with reasonable conductivity.”
The very simple model excluded geothermal and gravitational effects such as tidal flows etc which would only detract from the focus on these points.
I have exaggerated many physical effects to make radiative equilibrium as big a problem as I can make it.
If you can think of any further reasonable inflation of the problem please let me know and I will include it.
Including non related phenomena only make the case for human induced CO2 as a major problem much weaker.
Reasonable conductivity given the time scale of 1000 years is not “superconductivity”.
>>
152, DeWitt Payne said
April 29, 2010 at 4:30 pm
. . . The surface exposed to clear sky radiates 390 W/m2. ~100 W/m2 of that goes directly to space. . . . So yes I do believe with good reason that no IR from the surface is transmitted directly through cloud cover. . . . If you can’t see how that balances, you haven’t read the article carefully enough.
<<
It's interesting that because you believe something, I must have poor reading skills. Actually, I've read Trenberth's paper several times. I have yet to find where he claims that 0 W/m^2 is the correct or approximate value for the window’s cloudy case. Let me re-quote from his paper, and you can tell me where my reading comprehension goes awry: "In the clear sky case, the radiation in the window amounts to 99 W/m^2, while in the cloudy case the amount decreases to 80 W/m^2 . . . ."
He says 99 W/m^2 for the clear sky (not approximately 100 W/m^2). Then he says 80 W/m^2 for the cloudy case (not 0 W/m^2).
Jim
Re: Jim Masterson (Apr 30 02:21),
Then that’s a mistake or at least a mis-statement in the paper. Looking at the cartoon, I suspect that the actual figure should either be 50 W/m2 rather than 80 W/m2 for the window for clouds or that the cartoon is wrong and the cloud tops emit 50 W/m2 directly to space rather than 30 W/m2 and the atmosphere emits 145 W/m2 instead of 165 W/m2. There is no question that clouds are opaque to IR from the surface. That still doesn’t get you to a missing 47 W/m2.
You can use MODTRAN for a quick and dirty analysis of the long wave balance. It isn’t quite correct because the MODTRAN calculated fluxes don’t include the full range of the thermal IR but:
Clear sky, 1976 standard atmosphere, default conditions:
0 km looking up: 258.673 W/m2
100 km looking down: 258.799 W/m2
cumulus clouds base 0.66 km, top 2.7 km
0 km looking up: 359.216 W/m2
100 km looking down: 222.155 W/m2
Cloud type makes little difference in the numbers so I just picked the first one. Now lets solve for the fraction of cloudy vs clear sky that gives 324 W/m2 from 0 km looking up
x*359.216 + (1-x)*258.673 = 324
100.543*x = 65.327
x = 0.65
That looks about right. Now we’ll plug that into the numbers for 100 km looking down:
0.65 * 222.155 + 0.35 * 258.799 = 235 W/m2
Funny how these things work out. In the end, the exact size of the window to space is really not important to the argument.
Re: Suibhne (Apr 29 18:25),
I just showed you that for a very good heat conductor, copper, a temperature difference of 5,000 degrees only produces a net heat flux of 0.33 W/m2 for a distance of 6,000 km. Heat flux is proportional to the difference in temperature for a finite thermal conductivity. Unless the surface heats first, there will be no heat flow to the core. None. Zero. Zip. Nada. Your calculation does, in fact, assume that the planet is isothermal and therefore superconductive. Deal with it.
DeWitt Payne
My simple model has many flaws such as;
The Earth absorbed all the Suns radiation that landed on it and absolutely no heat ever escaped.
The use of the full solar radiation figure of 1377W/m2 whereas only half that value reaches the Earths surface.
Despite these exaggerations to make radiative equilibrium as big a problem as I can it turns out that the total output of the Sun over a thousand years could not increase the temperature of the bulk of the planet by one degree.
Yet there are many proponents of AGW who think that CO2 will lead to an increase in the Earths average temperature of as much as eight degrees in the next century.
You may be a particularly sophisticated AGW proponent who restricts your concerns to the top metre of the planets surface and the troposphere.
However the post was for those who think that the whole planets temperature is increasing dangerously.
Re: Suibhne (Apr 30 11:49),
The sun has no significant effect on the bulk temperature of the planet. It only affects a thin layer near the surface. If your understanding of heat transfer physics is so poor that you can’t understand why that is true, there is no point in my continuing this.
Or to put it another way: If the Earth were teleported to inter-galactic space millions of light-years from any sun, would it take 1000 years for the surface temperature to drop by 1 degree? According to you, it would.
I think you meant the bulk wouldn’t drop by 1 degree right?
Re: Jeff Id (Apr 30 17:00),
No, I mean the surface. Suibhine seems to me at least to be arguing that an increase in forcing doesn’t have any effect on the surface temperature because you have to warm the bulk of the planet as well as the surface. A doubling of the solar constant, for example would take 1000 years to increase the temperature by 1 degree. Turning that logic around, cutting the solar constant to zero would then mean the the surface would take 1000 years to cool by 1 degree. That’s so obviously
insanewrong that I don’t understand why he can’t see it. In fact, cutting the solar constant to zero would have an insignificant effect on the bulk temperature of the planet, but would have a major effect on the surface temperature. The only way his argument could be true is if the planet were an isothermal superconductor. He clearly doesn’t understand that either.Hope the strikethrough shows up in the post as well as it does in the preview.
#161 Ah, I read your comment backward somehow. it would instead of would it.
DeWitt Payne
To put it another way;
To increase the internal energy of the mass of the planet by one degree centigrade using the full solar output falling on the Earth would take in excess of one thousand years.
I notice you have not dared to question the energy calculation.
Instead you choose to find weak excuses.
The proposition is clear and quite straightforward.
If every molecule in the Earth increased its temperature by one one degree centigrade using the full solar output falling on the Earth how much longer than one thousand years would you calculate it to be?
Re: Suibhne (Apr 30 18:04),
Idiot.
*Plonk*
DeWitt Payne
Perhaps you should look again at my post 149
“Kevin Trenberth is recently finding his sums don’t work out within radiative balance.
However he should relax,there is no such law in physics.”
Kevin Trenberth has recently admitted quite frankly that he cant account for the “missing heat”.
He thinks that it may be at the bottom of deep oceans and that it will come back to “haunt us”.
This indicates that he at least is not just looking at the surface temperature.
This brings to mind a scene from Monty Python and the Holy Grail. Does the phrase: “Oh, oh, I see, running away, ‘eh? … You yellow bastards! Come back here and take what’s coming to you…. I’ll bite your legs off!” mean anything to you?
DeWitt Payne
“Idiot.
*Plonk*”
The ability to hurl personal insults is inversely proportional to any rational contribution you can make.
It is pointless communicating with a verbal hooligan.
I’ve interviewed Dr. Miskolczi twice for Examiner.com articles I’ve written, and have found his “equilibrium theory” to be thought-provoking and worthy of further scientific review.
I have not seen a refutation of his work.
Dr. Miskolczi’s explains theory
http://bit.ly/cHYVdc
Miskolczi defends theory
http://bit.ly/dgjBSO
Dr. Zagoni’s follow-up article
http://bit.ly/90pDEj
Dr. Miskloczi’s research papaer (for those with a mathematics background)
http://bit.ly/bmtWp8
My recent Examiner.com story addressing the logarithmic properties of CO2
http://bit.ly/cSa01R
Re: Kirk Myers (May 1 12:36),
Let’s see.
His formulation of the Virial Theorem is incorrect for an atmosphere consisting of molecular gases (Miskolczi PE=2KE, Toth 5PE=2KE). No one, including Miskolczi, has explained how he gets from the (incorrect) Virial Theorem to his formula for the (nearly constant) optical depth, much less come up with a mechanism to enforce a drop in water vapor for an increase in CO2 or other ghg. Everyone I’ve heard of that has the proper math background has been able to understand his work. There are too many non-intuitive steps left out. Either that or there really isn’t a way to get there from here. Since hardly anyone takes his work seriously, no one of any stature is going to waste their time on publishing a refutation.
DeWitt,
I’ve always liked the guys, bicycle manfacturers, that flew the planes. I believe they were from North Carolina.
Kirk
I don’t know what’s right or wrong. But let’s at least take a look. Dr. Miskolczi’s math is way beyond me. But look at the reaction from certain people. Some folks are worried about the money.
169:
“His formulation of the Virial Theorem is incorrect for an atmosphere consisting of molecular gases (Miskolczi PE=2KE, Toth 5PE=2KE). No one, including Miskolczi, has explained how he gets from the (incorrect) Virial Theorem to his formula for the (nearly constant) optical depth, much less come up with a mechanism to enforce a drop in water vapor for an increase in CO2 or other ghg. Everyone I’ve heard of that has the proper math background has been able to understand his work. There are too many non-intuitive steps left out. Either that or there really isn’t a way to get there from here. Since hardly anyone takes his work seriously, no one of any stature is going to waste their time on publishing a refutation”
Well, it is ALSO getting real hard to take seriously the “conventional physics” espoused by Dr. Payne, since there has been no warming for about 15 years. Where is the empirical evidence, DeWitt?
I especially get a kick out of this phrase, which reeks of “warmist” and RealClimate phraseology and psycology: “no one of any stature is going to waste their time on publishing a refutation” Now, that just does not display a propber scientific attitude and it really begs the question as to whether any of those with “stature” can possibly refute him. I guarantee you that if Dr. Payne and his supporters COULD refute Dr. Miskolczi in a peer-reviewed journal, they would have done it years ago. Since they have not, then I still think MAY have some truths. Methinks thou dost protest too much….?
BTW, folks, you might notice that Dr. Payne does not respond to my comments anymore. Could it be that he has “tuned me out,” because I won’t agree with him??? Is this how science advances? LOL!
Meanwhile, I’m still anxiously awaiting some rational responses to Nos 129, 136 (i.e., is there any empirical evidence for the greenhouse effect?).
Oh, I forgot to mention that one of the reasons that the “warmers” are so upset with other theories, such as the one by Miskolczi, is that some of those theories actually appear to be supported by empirical envidence. This is how science is supposed to work, and they should know that. It is the OPPOSITE of the conventional hypothesis, which has NEGATIVE empirical support (which means FALSIFICATION–no warming at the surface or upper troposphere, ALL GCM models wrong, thickening artic ice, ad nauseum). No wonder they are a dying breed.
JAE:
It’s not just conventional wisdom. It’s basic physics.
The Earth is more complicated than a laboratory bottle of air, and there is no simple linear relationship between global mean temperature and atmospheric CO2 concentration, Iit’s not even guaranteed that increasing CO2 in the atmosphere even increases global mean temperature… you could have a hypothetical feedback relationship between CO2 concentration and e.g. cloud forcings that increases cloud cover in response to increased CO2 (at least short term).
But the fact that CO2 acts as a climate forcing isn’t in doubt, which is Jeff’s original point. We all recognize that the relationship is complicated, all we can say is the Earth would be much colder without CO2 in the atmosphere and much hotter if it were nearly all CO2.
On the Kiehl/Trenberth’s papers.
Recently I came upon a revised KT diagram.
The value of 390W/m2 for surface radiation I had been using( SB gives e=1 for 15degrees c).
Has now been replaced by 396 W/m2.
Yet if we use SB equation and 15 degrees Celsius this means that the value for emissivity is now 1.015 I don’t think that this is physically possible.
What do other readers think?
Or is everything possible in the KT “la la land”.
Suibhne said
May 2, 2010 at 4:47 am
On the Kiehl/Trenberth’s papers.
What do other readers think?
Or is everything possible in the KT “la la land”.
I do not think anything further needs to be said,
except the possible addition of “politically correct and future funding assuring”
ie,
Or is everything possible in the politically correct and future funding assuring, KT “la la land”.
# 169
DeWitt, if you are unable to compute things yoursef why do not you ask V. Toth about this?
I had some valuable discussions with him. Here is some communication with V. Toth:
“…..Regarding the final clause in my paper, I found it important to stress that the degrees of freedom must be considered, while at the same time, I did not wish to actually criticize Ferenc’s paper. A good thing, too, because in his latest e-mail, Ferenc made it clear that he did account for the degrees of freedom, he just did it differently (rather than accounting for it in his expression of the virial theorem, he only considered the kinetic energy per the vertical translational degree of freedom to begin with.) I do find this a little confusing (I don’t think this is clearly explained in his paper) but the result is correct, and that’s what matters in the end…”
Regarding your other comment: …”Since hardly anyone takes his work seriously, no one of any stature is going to waste their time on publishing a refutation.” …First, People can not refute empirical facts, and second, I am quite happy that only those few scientists take my results seriously who understand them, and I am really happy to work with them on further improvements. Unfortunately Jeff is not among them…
174, Carrick: Yes, the radiation occurs, as Jeff and DeWitt point out, but IT APPEARS THAT THE SYSTEM IS NOT RESPONDING IN THE WAY IT’S “SUPPOSED TO.” Ergo, the AGW physical theory might just be falsified; it might just be pure garbage. It is beginning to look like something ELSE is controlling temperature.
BTW, if that little laser experiment cited in 136 is true, then even the basic radiation mechanisms espoused by Jeff are wrong. Wish I had the materials to repeat it.
Carrick, 174:
“It’s not just conventional wisdom. It’s basic physics.”
The problem is that this basic physics is not enough to explain how the system behaves. For example, answer my question in 129. How do you explain the temperatures in Fiji with a radiation cartoon? When one deviates from some hypothetical average equilibrium situation shown in the radiation cartoons, nothing seems to “work.” Maybe this is because radiation varies with T^4, so “average condtions” mean nothing.
#100 Dewitt Payne
“MODTRAN calculation: 1976 standard atmosphere, 0 km, looking up, all other settings default
280 ppmv CO2 257.323 W/m2
560 ppmv CO2 260.526 W/m2
…
MODTRAN isn’t a toy model. It’s results have been validated against observations in the real world.”
I wonder about this (some of it anyway). I have not checked the underlying data used to graph (from the available text file in order to make sure there is not a graphing bug), but for the distribution profile graphs you see in MODTRAN, look at the vertical distribution shown for C02 in any of these calculations.
For example, in your first example, it starts at 280 ppm at 0km, increases to (eyeballing) ~350ppm at 10km (tropopause), remains somewhat constant up till ~45km then decreases slightly, then increases to ~350 at 70km.
I have looked to find justification for this vertical profile and have not been successful.
This paper reporting CO2 measurements up to 8km seems to contradict the dramatic (70-80ppm) increase through the troposphere (in general the MODTRAN model uses the same profile and just translates it to the chosen CO2 ppm starting value):
(http://www.tiimes.ucar.edu/events/presentations/stephens_tiimes_eol_070418.pdf Page 14)
Re: Ferenc M. Miskolczi (May 2 10:10),
I suggest that this may be the problem, and not just with the degrees of freedom. For example, one thing I’ve noticed in comments about your paper is that no one understands how you get from the Virial Theorem to your expression for tau. There appear to be steps left out that are not obvious to the skilled reader.
Re: kevoka (May 2 13:04),
I’ve plotted the MODTRAN tabular data in atm-cm/km as a function of pressure and it looks pretty linear through the troposphere. Converting atmosphere centimeters/kilometer to ppmv is tricky. The unit is the length in centimeters of a horizontal column of the gas of interest, in this case CO2, if it were at STP. But in this case, rather than using the entire column of the atmosphere from the measurement point upward, it’s expressed on a per kilometer basis. At sea level, the atmosphere is about 9 km long. I think that make the RT calculations easier as the program uses 1 km thick layers up to 25 km. I’m guessing that the correction for atmospheric density wasn’t done properly when converting back to ppmv and that’s why the graph looks funny. I may email David Archer and ask him about it, but I need to try some calculations on my own first.
JAE:
The problem with this statement is you are presupposing what the system is “supposed to do”.
We’ve said here an innumerable number of times that there is no simple linear relationship between atmospheric CO2 concentration and global mean temperature. For starts, it’s the sum over forcings that matters, and if CO2 is getting balanced by sulfate emissions, you must include that in your analysis too.
If we simply applied a “naive model” for CO2, we’d start with the concentration level in 1980, not 1850, assume that sulfate emission radiative forcings have remained constant since then (this is almost certainly false, but sulfate emissions are poorly measured even today), assume a “reasonable” value for the CO2 environmental climate sensitivity and.. we’d find a net expected change in temperature from 1850 to current from anthropogenic activities to be around 0.3°C.
Secondly, there are well known atmospheric-ocean oscillations… these cause fluctuations in global temperature on the order of tenths of a °C, and the periods for these oscillations vary from a few years to decades.
So my point is: Direct evidence of anthropogenic warming on global mean temperature to date is small, and of the same order as natural climate fluctuations. In order to reliably observe a variation as small as 0.3°C would require a measurement period of roughly 60 years. You are demanding something from the data, that the data cannot yet reveal (at least not without correcting for atmospheric-ocean oscillations).
Secondly…individual regions need not track in a linear relationship to changes in global mean temperature. For example, polar regions see a net amplification from global warming (due to any causative agent) relative to the equator.
Secondly, as you make the region smaller, the effect of atmospheric-ocean oscillation fluctuations INCREASES. Instead of talking about climate fluctuations on the order of tenths of a °C, you’d see fluctuations on the order of degrees. Obviously this would completely mask a fairly small global-scale perturbation.
Thirdly, cartoons are useful for illustrating models, they are not models, not even toy ones. Trying to demand that a simple cartoon can be used to explain anything is overstretching its capabilities.
Fourthly, laser measurements are the preferred method for determining CO2 concentration, using much of the same radiative physics used in determining that CO2 is a GHG. The idea that one can show something invalid that has been replicated in the 10s if not 100s of thousands of times, obtained in a much more careful experimental setup, is just absurd. I wouldn’t bet any quatloos on this one being right.
FINALLY, I’m not responsible for how some AGW activists misuse, torture and otherwise abuse CO2 radiative science to exaggerate their politically-inspired points, nor am I responsible for the degree to which they either don’t understand point one above, or just gloss over or even lie about it (I quit reading the skeptical science blog because they couldn’t be honest over this point for example).
To summarize my view, the effect of anthropogenic activity on temperature to this date isn’t a “big deal” (hell, it’s barely measurable), but with continued CO2 emissions it will eventually become a dominant driver of global mean temperature. Also, there are other ways besides temperature that we can affect our climate, e.g., precipitation patterns, ocean acidification, etc. These are independent issues, and hence “anthropogenic climate change” or even “environmental impact” is a better way to frame the problem than simple “global warming”.
Hope this clarifies more than it obscures.
Re: kevoka (May 2 13:04),
I can duplicate the Archer MODTRAN CO2 plot if I correct for pressure but not temperature. If I correct for temperature as well then I get 50 atm cm/km +/- 0.1 or 500 ppmv for all altitudes from 0 to 70 km for an input setting of 500 ppmv. The ratio of CO2 to O2 in atm-cm/km is also constant at all altitudes so the radiative calculations are probably correct. It’s the profile graph that’s wrong. He has it wrong for CH4 and O3 as well, but the difference for O3 is insignificant to the eye on the graph. I haven’t figured out what he’s doing for water vapor.
I should say I wasn’t doing water vapor partial pressure correctly. Once I figured that out, he’s not correcting water vapor volume for temperature either. It’s too low on the MODTRAN graph, although not by very much.
183, Carrick: Thanks. I don’t think we disagree TOO much, except.
“To summarize my view, the effect of anthropogenic activity on temperature to this date isn’t a “big deal” (hell, it’s barely measurable), but with continued CO2 emissions it will eventually become a dominant driver of global mean temperature. Also, there are other ways besides temperature that we can affect our climate, e.g., precipitation patterns, ocean acidification, etc. These are independent issues, and hence “anthropogenic climate change” or even “environmental impact” is a better way to frame the problem than simple “global warming”.
You have absolutely no basis for saying that CO2
Dewitt,
Interesting. I appreciate your answers.
Dammit. This computer hates me. To continue:
You have absolutely no basis (in science, anyway) to state that “continued CO2 emissions will eventually become a dominant driver of…” anything! That is my whole issue. Nobody has yet demonstrated that CO2 has ANY effect on the Earth’s temperature. “Basic physics” doesn’t do it, Carrick. It takes empirical evidence, and all the evidence so far (it seems to me) points to falsification of the CO2 “crisis.” There is no “hot spot” in the upper troposphere in the tropics, as the models (which are presumeably based on this “basic physics”) predicted. There is no continued warming, demonstrating clearly that something else (maybe natural oscillations, as you say) is much more powerful than OCO. Ice core records show that OCO concentrations FOLLOW temperature rises by hundreds of years.
BTW, I want to see the “basic physics” demonstrated for Fiji, where the temperature and radiation is fairly constant year around. Just what does a radiation cartoon look like for a tropical paradise at noon? You have to explain maybe thousands of watts total radiation at noon on a sunny day, if you consider surface, solar, and “backradiation.” A blackbody under this type of radiation could be a steam engine!
Carrick: I’m sure you will agree ? that one of the most prescient spokesmen in this fray is Steve McIntyre. Here is a line from his latest post:
“My own sense – a view previously expressed at CA – is that in order to provide the appropriate food for a scientist from another field, there is a pressing and long overdue need for exposition somewhere between a primary school cartoon and merely reporting the results of GCM runs, meritorious as they may be. I suggested this long ago to one of the scopers of AR4 and it is something that the scopers of AR5 need to consider. My guess is that an exposition building on radiative-convective models a la Ramanathan would be the most fruitful way of accomplishing this. SD’s fresh presentations of Ramanathan’s work should be of considerable interest to people trying to understand the larger problem.”
http://climateaudit.org/2010/05/02/scienceofdoom-com/
I agree with this view. Where is the beef?
What will you bet that nobody will produce such exposition?
Oh, and it would be really interesting to see Dr. DwWitt address this issue. He really has to get out from his funk/cave into the real world, where radiation is not the only “game in town.”
JAE, we aren’t that far off, you are correct.
It is a supposition on my part that the long term radiative forcing from CO2 will result in a net temperature increase. Everything being even, I have a good chance of being right, but there are no guarantees here.
On Steve McIntyre.
He is right about the comparative silence of the IPCC on what should be major supporting evidence for IPCC.
The claimed backradiation figure of 324W/m2 has a huge magnitude.
Yet nobody has come up with a method of utilising such an abundant stream of photons for useful work.
Why don’t the IPCC want to highlight this area more?
My guess is that some of the evidence might in fact contradict the theory of AGW.
For the daylight part of the “backwarming” it is impossible to spit the radiation into straight from Sun and “back” from surface radiation.
The most trustworthy part will be mid nighttime backradiation.
IPCC problems would occur if either;
1. Very little showed a CO2 fingerprint.
2. Most of the radiation was had a longer wavelength than 16 microns.
#181
DeWitt,
I agree that it is not a matter of the degrees of freedom alone, but if you take it wrong (like Toth) then you get nowhere. You started that I am wrong because: “Miskolczi PE=2KE, Toth 5PE=2KE “. Now I agree with Toth that for any hydrostatic atmosphere PE=2KE, and the virial temperature (under an external gravitational force) should be computed from one degree of freedom. Am I and Viktor right or wrong? Or you just do not have any opinion?
Suddenly you jumped to the question of tau. Unless you know what tau means and how to compute it according to its definition the discussion about tau with you is meaningless. Nor Modtran, nor the band models of Ramanathan, neither Kiehlh & Trenberth etc. can help you with this. You yourself must come up with a numerical value of tau to argue with my tau=1.87 (as the observed clear sky tau for the Earth’s atmosphere). Unfortunately, so far there is no published global average Planck mean infrared flux optical depth available, so you can be the second with your new tau. There is a hint in the Appendix A of my 2007 paper… Once you get there and we observe a reasonable agreement, then we shall have a good ground to continue our discussion and move again towards the virial concept…
Finally, I am not a meteorologist or a climatologist and my 2007 paper was not particularly written for them. It was written for physicists and astrophysicists and also to my poor former NASA boss – as a present. Further on, I do not care if the planet is warming or cooling, however, people should know that the CO2 greenhouse effect based AGW is a lie, and IPCC knows nothing about the true nature of the greenhouse effect.
Re: Ferenc M. Miskolczi (May 3 15:21),
Indeed. The question I’ve found repeated often is: What does the Virial Theorem have to do with tau?
A hint? Why not a complete derivation? I’m not the one who has to come up with my own value of tau. You’re the one that needs to convince people, not me.
Hmmm… EARTH TO DR. DEWITT: Miskolsczi has some empirical evidence for his hypothesis. You have none. Please read Popper’s stuff on real science.
Ferenc M. Miskolczi said
May 3, 2010 at 3:21 pm
Unless you know what tau means and how to compute it according to its definition
Hello Dr. Miskolczi, the below are genuine questions on my part, put in simple terms.
1) Is the below an accurate description of what tau means. ?
tau = 1.87
The number of times (expressed as a globally averaged figure) that an IR photon emitted at the earth’s surface
is refelcted back to the earth’s surface, before the photon escapes to space.
2) Does the virial theorum imply an induced by gravity (base) temperature of the atmosphere.
If so, is this a constant heat input to the atmosphere, other than the sun, or geothermal heat, by gravity. ?
3) Are you aware of Tim Casey’s article in regards to Kirchoff’s law. ?
http://greenhouse.geologist-1011.net/
194#
DeWitt,
“…The question I’ve found repeated often is: What does the Virial Theorem have to do with tau?…”
Are you serious? The virial relationship we are talking about is the relationship between the gravitational potential energy and the temperature of the gas held together by gravity. The IR optical depth of the atmosphere tells you how much surface radiation are absorbed within the atmosphere, contributing to its internal energy. Think of the two extreme cases, when the gas atmosphere disappears. If there is no SW absorption (at the surface)the atmosphere will be condensed out and sitting frozen on the ground. If there is too much SW absorption the atmosphere will be boiled off into space.
The description of tau in Appendix A is complete enough, and I think it is sufficient for skilled people to reproduce the computations. I do not need and do not want to convince people about tau=1.87 . If there is a doubt, the interested people should convince themself whether this tau is real or not. So far I can not argue with anybody about this tau since – as I told you -nobody computed it. If you are able to do it, compute it and we shall get somewhere. If you can not compute it, then you have no basis to criticize it (based purely on your feelings or other people’s opinion) . To refute the tau=1.87 you must prove that my computation is wrong. Do not wait for NASA or the IPCC, they could not do this in 6 years (or, if they did, they will not tell you, or pubish it, since it is not a politically correct action)…
Ferenc, while no peer reviewed paper has come out critiquing your paper you may be interested that the Australian government has seen fit to respond:
http://www.climatechange.gov.au/climate-change/science/climate-sceptics.aspx
There is no doubt Ferenc’s paper has been the most discussed paper on the blog since its publication; perhaps the most detailed critique is by Steve Short who said this:
“Here is another run of the basic spreadsheet (slightly expanded to improve self-explanation) for my little model. This time I once again kept S_U = 396 W/m^2, OLR = 239 W/m^2, F=78 W/m^2 again all as per the T,F&K09 review (see the cartoon therein).
However, I also forced rE_U (i.e. the real E_U) to be 169 as per T,F&K09 and I set S_T to average 40 at 60% cloud cover again as per T,F&K09 (rather than the 31±10 of the CERES and ERBE averages).
All other assumptions were as listed previously including that again I assumed E_D~0.625(ET+DT)+0.5F+0.625A_A on the grounds I have previously explained above.
Once again I set Dry Thermals (DT; convective sensible heat) to be 17 W/m^2 at 60% cloud cover but as before scaled DT to be 0 at 100% cloud cover and 34 at 0% cloud cover. This is a conservative assumption in that it tends to force my estimate of E_D towards A_A i.e. in the direction of Miskolczi’s so-called Atmospheric Kirchoff Law. One could just as easily run this assuming DT = 17 at all cloud covers (probably unlikely physically) and the outcomes would only be trivially different.
Here are the results:
%Cloud, Tau, S_T, ET, ET_U, DT, rE_U, A_A, E_D, oE_U, S_U/oE_U, A_A/E_D, S_U, OLR, F
100 2.99 20 133 50 0 169 376 357 219 1.81 1.05 396 239 78
80 2.58 30 107 40 8 169 366 340 209 1.89 1.08 396 239 78
60 2.29 40 80 30 17 169 356 322 199 1.99 1.11 396 239 78
40 2.07 50 53 20 23 169 346 303 189 2.10 1.14 396 239 78
20 1.89 60 27 10 29 169 336 284 179 2.21 1.18 396 239 78
0 1.73 70 0 0 34 169 326 264 169 2.34 1.23 396 239 78
It can be seen that the real (LW IR) Tau ranges from 1.73 at full clear sky to 2.99 at full 100% cloud cover being 1.89 i.e. ~1.87 only at 20% cloud cover.
The Miskolci ‘Kirchoff Law’ test ratio A_A/E_D ranges from 1.05 at 100% cloud cover to 1.23% at clear sky
The Miskolczi ‘Virial Rule’ test ratio S_U /oE_U (i.e. S_U /old E_U) ranges from 1.81 at 100% cloud cover to 2.34 at clear sky. It is 1.99 i.e. ~2.00 only at 60% cloud cover i.e. at the global all sky % cloud cover.
I would be happy to send back to anyone, if they send an email to me, a copy of this little Excel spreadsheet so they can play around with it themselves. Your email address would not be recorded.
You can then make up your own minds what this simple exercise tells you about:
(1) the likely validity of the major tenets of Miskolczi Theory; and
(2) the significance of LW IR by release of latent heat in clouds (water emission lines) which typically escapes to contribute to OLR (as a simple function of % cloud cover).”
This is from a Niche discussion
What does Ferenc think?
The issue of back-radiation has come up and I see reference to some of Alan Siddon’s comments; Alan is always good value. Ever since Philipona’s work back-radiation has been one of the sticking points of AGW for me; the greenhouse effect depends on it; this paper is the best refutation, or rather alternative explanation;
http://biocab.org/Induced_Emission.html
Re: cohenite (May 6 22:58),
OMG, not Nasif Nahle again. He’s the reason I know about Hottel. He also completely misunderstood how to use Hottel’s data and as a result underestimated the emissivity of CO2 in the atmosphere by orders of magnitude because he neglected path length.
DeWitt; by path length do you mean what defines a local thermodynamic equilibrium [LTE]? In an LTE the mean free path of a CO2 molecule is defined as how far it must travel before it strikes a molecule of different temperature; convection in the atmosphere is based on LTE’s; discrete parcels of air are moved vertically according to lapse rate differences with the LTE condition; my point is, while LTE conditions limit energy transfer between the LTE and the external atmosphere don’t they also limit backradiation? Nahle doesn’t seem to be arguing against the idea of backradiation or the isotopic effect of emission but that the warmer night-time surface of induced emission prevents, blocks [traps :-)] the isotopic spontaneous emissions of backradiation; the LTE would be the mechanism of that.
I have been battling to try to understand (and hence believe) Miskolczi’s theory now for a long, long time but alas I cannot.
This little spreadsheet (link below), now in its umpteenth incarnation, AND admittedly still far from perfect, arose from my attempts to reconcile the global heat budgets of K7T97, and much more recently T,F&K09, Loeb at al 09 (both versions), ISCCP-FD, NRA, JRA with Miskolczi’s ‘world view’ and also an attempt to understand Dr. Jeffrey Glassman’s position (which I find BTW to be far more rational than that of Miskolci).
What my efforts have seemed to show, incidentally is that, quite contrary to Miskolczi’s claims:
* A_A does not = E_D (ever)
* OLR/S_U does not = 3.2 – indeed it is closer to 5/3 for the typical range of average global cloud covers.
* the true cloud free LW IR tau is probably closer to about 2.3 and is nowhere close to 1.87.
Have fun (Dewitt will I’m sure):
https://download.yousendit.com/bFFOTXRUMGNUWUJjR0E9PQ
Note: Virus checked.
Thanks Steve; I should have asked your permission first but the version I posted was at the Niche discussion so I didn’t think you’d mind. In the download both the SW and LW tau remain constant in the columns; why is that? And the % of surface temp applies to all ghg’s, ie water, not just CO2?
“In the download both the SW and LW tau remain constant in the columns; why is that?”
Because, just as Dewitt correctly said (back at #155) “There is no question that clouds are opaque to IR from the surface.”
Thus, if you look closely at the formula for the LW IR tau you will see that it correctly normalizes the S_T to (1-CC), CC being the cloud cover, thereby ensuring that the tau calculation accounts for the opening and closing of the ‘cloud free’ window with increasing/decreasing cloud. By definition the tau applies to the cloud free ‘window’ (of course).
Having said all that we have to remember that the main reason why this little spreadsheet is still a crude approximation is that humidity within that window must varies as cloud cover changes (and this changes the LW IR tau to a secondary degree). BTW this is likely to be the reason why my crude spreadsheet gets the cloud free S_T to be ~98 W/m^2 when it should be ~92 W/m^2.
However, we can still ensure that we get S_U right (and hence S_T) for the cloud free situation because it is well known that the current normalized greenhouse factor (little) g ~ 0.333 (Ramanathan etc)
Hey we even have Miskolczi himself to tell us that – even though we can also see his (next) silly contention that it should always 0.333 for the entire cloud cover range must also be wrong – of course! (;-)
“And the % of surface temp applies to all ghg’s, ie water, not just CO2?”
You are going to have to much, much clearer there: “…% of surface temp…” What on Earth do you mean by that?
Re: cohenite (May 7 04:14),
No, I mean the optical path length or more precisely, the mass path length. The data in the tables were for a path length of 1m (IIRC, it’s been a while). Nasif used the number that corresponded directly to the concentration of atmospheric CO2. But the actual path length is ~10 km. That doesn’t make the emissivity four orders of magnitude larger because the emissivity is still non-linear. But it does make it a lot larger. But Hottel’s data is intended to be used in more or less isotropic conditions and is usually applied to things like heat transfer in a coal or gas-fired electric power plant. Nasif refused to accept this and actually denied that the data I was using was really from Hottel because it wasn’t exactly like his source. But there are several variations of Hottel depending on the geometry of the system. The discussion is in one of the old Unthreaded threads at Climate Audit, specifically Unthreaded #21 starting with my comment here. You might have to look at a linked discussion at UKWeatherworld as well.
Thinking about it, I suspect that Hottel’s mass path length may correspond to atm cm which is the length in cm of the the total CO2 (or whatever gas) in the entire atmosphere above a unit area if you made the column horizontal at standard temperature and pressure and segregated the gases into their own compartments. For CO2 from the surface, that’s ~300cm or 3m, not 0.0004.
“You are going to have to much, much clearer there: “…% of surface temp…” What on Earth do you mean by that?”
Column AL, Tsurf from GHG forcing.
Hi Anthony
The conventional picture is as follows:
The net power deposited in the terrestrial atmosphere and surface depends on the solar irradiance and the Earth’s short-wavelength (0.15–4.9 microns) albedo and is:
Pin=CRe^2(1-A)
where C is the solar constant (adjusted for the Sun-Earth distance), Re is the Earth’s radius, and A is the short-wavelength Bond albedo (the amount of sunlight reflected back to space by the atmosphere and surface of the Earth). Subsequently, the short-wavelength, incoming power is re-radiated back into space at thermal or long-wavelengths (peaks near ~10–15 microns), where
Pout=4Re^2σTtoa^4
where σ is the Stefan-Boltzmann constant and Ttoa (~255 K) is the effective temperature of the Earth (defined with unit emissivity). Ttoa is a physically averaged long-wave emission temperature at about 5.5 km height in the atmosphere (this “top of the atmosphere’’ or “toa’’ temperature depends on wavelength and cloud cover; altitudes from 0 to 30 km contribute to this emission).
One can relate that temperature to a more relevant global climate parameter like the globally averaged surface temperature Tsurf by introducing a greenhouse forcing parameter G [W/m2], which is defined as the difference between the emission at the top of the atmosphere (OLR) and the surface (S_U in my spreadsheet using Miskolczi’s terminology) i.e. G = S_U – OLR
The forcing G increases with an increasing concentration of greenhouse gasses. After Raval and Ramanathan (1989), one defines the normalized greenhouse factor g as g=G/σTsurf^4. Then the outgoing power can be written as:
Pout=4Re^2σ(1-g)Tsurf^4
IF repeat IF the planet is in radiative equilibrium, Pin=Pout, then we have
Tsurf^4=(1-A)[C/(4σ(1-g))]
This means that the Bond albedo, together with solar irradiance and the greenhouse effect, directly controls the Earth’s temperature. Global warming would result if either A decreased or g or C increased.
So in my little spreadsheet model, the Tsurf in Column AL to which you refer is the Tsurf calculated according to the above (radiative equilibrium) formula. It (correctly) shows the temperature which would apply at the surface IF and only IF the planet was in radiative equilibrium at any fixed value of C and A. And yes, for any fixed level of GHGs.
BUT, the planet is NOT in radiative equilibrium at each and every value of C and more particularly A (Albedo). Albedo is continually varying – it is a ‘moveable feast’ simply because the main influence on Albedo is Cloud Cover (and cloud type).
Secondly, and this is where a Jeff Glassman scores (wisdom-wise) in spades over a mere Miskolczi: what drives Cloud Cover up and hence Albedo up is Tsurf. Thus Albedo rises with increasing surface temperature. This is the exactly opposite trend to that which is given by the simplistic radiative formula
Tsurf^4=(1-A)[C/(4σ(1-g))]
for any fixed g.
Tsurf is never constant, A is never constant, g is never constant, the Earth is only ever close to radiative equilibrium at a long term cloud cover and most importantly Albedo is proportional to Tsurf (and vice versa) and NOT inversely proportional.
My little spreadsheet model is a ‘play tool’ attempt to better understand this reality.
Still no reply to 188? Please use “standard, accepted, physics” to explain why Fiji is not much hotter.
202#
Steve,
I appreciate that you still try to understand my 2007 Idojaras paper. It would be a great help to you if you could abandon the conventional thinking in this matter. If you really want to argue about my view you must move from the standpoint of a believer to the one of a scientist.
” A_A does not = E_D (ever) ”
COMPUTE IT PROPERLY AND YOU WILL SEE. YOU MUST SHOW ME AT LEAST ONE REAL
ATMOSPHERIC STRUCTURE WHERE IT IS NOT TRUE. E_D CAN BE MEASURED, BUT A_A CAN ONLY BE COMPUTED.
” OLR/S_U does not = 3.2 – indeed it is closer to 5/3 for the typical range of average global cloud covers. ”
I NEVER STATED WHAT YOU WROTE. I SAY IN M2007 THAT THE CLEAR SKY OLR/SU=2/3 (OF A CLOUDY EARTH), AND I ALSO SAY THAT THE GLOBAL AVERAGE ALL SKY RATIO IS 3/5, (SEE PAGE 7, BOTTOM LINE). THE g=1/3 is NOT RAMANATHAN INVENTION, IT IS THE CONSEQUENCE OF EQS. 7 AND 8.
” the true cloud free LW IR tau is probably closer to about 2.3 and is nowhere close to 1.87 ”
AGAIN, COMPUTE IT PROPERLY AND YOU WILL SEE. NOTE, THAT LITTLE ERROR IN TAU CAUSES LARGE ERROR IN A_A.
Dewitt, very interesting, your exchanges with Jan, Steve’s old sparring partner. Given your comments would it be fair to say that you subscribe to the view that there is no saturation of CO2 at any level of concentration?
Ferenc, you say:
“COMPUTE IT PROPERLY AND YOU WILL SEE. YOU MUST SHOW ME AT LEAST ONE REAL
ATMOSPHERIC STRUCTURE WHERE IT IS NOT TRUE. E_D CAN BE MEASURED, BUT A_A CAN ONLY BE COMPUTED.
I cannot see this. For example:
The original K&T97 global heat budget based on the ERBE measurements implies A_A/E_D ~ 1.08. This is significantly different from 1.00.
The T,F&K09 global heat budget based on the CERES measurements implies A_A/E_D ~ 1.08. This is significantly different from 1.00.
The Loeb et al. 09 original (‘old’) global heat budget based on the CERES measurements implies A_A/E_D ~ 1.08. This is significantly different from 1.00.
The NRA global heat budget based on the CERES measurements implies A_A/E_D ~ 1.08. This is significantly different from 1.00.
The Loeb et al. 09 revised (‘optimized’) global heat budget based on the CERES measurements implies A_A/E_D ~ 1.08. This is significantly different from 1.00.
The ISCCP-FD global heat budget based on the CERES measurements implies A_A/E_D ~ 1.08. This is significantly different from 1.00.
The JRA global heat budget based on the CERES measurements implies A_A/E_D ~ 1.07. This is significantly different from 1.00.
So, are you saying that all these groups are wrong? If so, please explain clearly how and why they are wrong?
When I estimate the clear sky A_A/E_D I get ~0.98. I would agree that this could be well be 1.00 within error but I can find no evidence in the literature for your contention that A_A/E_D = 1.00 under all sky conditions (incl. with cloud). But I am happy to be convinced (logically) otherwise. Your 2 papers do not do that, no matter what you have claimed.
“I NEVER STATED WHAT YOU WROTE.”
This is true . I meant S_U/OLR is not equal to 3/2 not 3.2. My apologies for the typo. Equivalently I meant OLR/S-U is not equal to 2/3.
“I SAY IN M2007 THAT THE CLEAR SKY OLR/SU=2/3 (OF A CLOUDY EARTH), ..”
I get the clear sky OLR/S_U from available literature data (other than your own) to be in a range of about 0.70 – 0.75. I do not see any literature consensus that it is close to 0.667 although I acknowledge the practical difficulties with this measurement.
“AND I ALSO SAY THAT THE GLOBAL AVERAGE ALL SKY RATIO IS 3/5, (SEE PAGE 7, BOTTOM LINE).”
It is true you say that (in your 2007 Idojaras paper) and I agree with you. From the literature and related personal estimations I get OLR/S_U ranging from ~0.59 at A (albedo) = 0.325 to ~0.61 at A = 0.280. But it clearly varies with average global cloud cover (albedo).
(Me)” the true cloud free LW IR tau is probably closer to about 2.3 and is nowhere close to 1.87 ”
AGAIN, COMPUTE IT PROPERLY AND YOU WILL SEE. NOTE, THAT LITTLE ERROR IN TAU CAUSES LARGE ERROR IN A_A.”
See what? How? I cannot see this at all. How do you ‘compute” that? In your various presentations (incl. with Zagoni) you have suggested that the average sky S_T is about 60 W/m^2 ( a value I can’t find supported anywhere) and the clear sky S_T is about 92 W/m^2 (more reasonable). Given that LW IR does not pass through cloud to any significant degree, the above numbers cannot be used to estimate a LW IR tau of ~1.87. However if one accepts the more ‘consensual’ values of the average (cloudy) sky S_T ~38 W/m^2 and clear sky S_T ~92 W/m^2 it is quite easy to derive a LW IR tau of ~2.35. Over to you.
“THE g=1/3 is NOT RAMANATHAN INVENTION, IT IS THE CONSEQUENCE OF EQS. 7 AND 8.”
This is a rather idiosyncratic claim. I have in front of me; “The radiative forcing due to clouds and water vapor” V. Ramanathan and Anand Inamdar, Center for Atmospheric Sciences, Scripps Institution of Oceanography, University of California, San Diego, CA., being Chapter 5 in “Frontiers of Climate Modeling”, edited by J.T. Liehl and V. Ramanathan, Cambridge Uni Press, 2006 in which they say:
The global average Ga is 131 W m−2 or the normalized ga is 0.33, i.e., the
atmosphere reduces the energy escaping to space by 131 W m−2 (or by a factor
of 1/3). The ocean regions have a slightly larger greenhouse effect (0.35 for ocean
vs. 0.33 for land) compared with the land (Figure 5.7b). In order to get another
perspective on the results shown in Figure 5.7, we note that a doubling of CO2
(holding the surface and atmospheric temperature fixed) will enhance Ga by about
4Wm−2. We should note that the ga shown in Figure 5.7 includes the greenhouse
effect of water vapor and all other greenhouse gases including CO2, O3, and several
trace gases.
They give references….
211#
Steve, you do not understand fundamentals.
The A_A can not be measured. Here you are left for your belief. About ten years ago while at NASA, (and working on the CERES and AIRS measurement validation) I computed the accurate A_A (probably I was the first who used an LBL code for this purpose) for them and I know exactly how to obtain those “significantly” different values. Further on, the KT LW computation is a joke, and I do not think it would make any sense to discuss here the role of the surface emissivity and the E_D anisotropy (in the A_A=E_D relationship).
You have that rather idiosyncratic claim that Ramantahan in 2006 was not aware of the Miskolczi & Mlynczak 2004 Idojaras paper where we wrote on page 238 (this is a reference to ” The greenhouse effect and the spectral decomposition of the clear-sky terrestrial radiation”):
” Eq. (8) shows the real physical meaning of the g=G/SU factor in Raval
and Ramanathan (1989). The normalized greenhouse factor and the total
atmospheric graybody optical thickness are uniquely related by the theory.”
The referred equation is g=(tau+exp(-tau)-1)/(tau+exp(-tau)+1). Since
g(tau=1.87)=0.338, I take Ramanathan’s measured global average g=1/3 as the empirical proof of my theory.
You can check this with Martin Mlynczak who is still at NASA Langley and working with the CERES team. Or ask King Ramanathan himself, I was not allowed to talk to him….
Not to take sides, but Ferenc has said that A_A can only be computed, and in every case of Steve Short’s disagreement, he computed a ratio of A_A/E_D without mentioning how a value of A_A was obtained. It does not seem to an outside reader that such an analysis somehow disproves Ferenc’s claims.
Oh, without further information regarding the quality of measurement or knowledge of the possible errors in a computation (particularly if there is an estimate involved), I would take exception to the claim that 1.08 is significantly different than 1.00. It may be, but without the added information, claiming so is specious at best.
Mark
When Ferenc says:
“About ten years ago while at NASA, (and working on the CERES and AIRS measurement validation) I computed the accurate A_A (probably I was the first who used an LBL code for this purpose) for them and I know exactly how to obtain those “significantly” different values.”
He may well be making a fair claim. As I have already stated that I accept A_A = E_D in the clear sky extreme so there is no argument on that point. However I do not accept the mathematical validity of Ferenc’s ‘mathematical proof’ that A_A=E_D at all values of cloud coverage and (I note) no-one else working in the mainstream field and publishing in the literature does either. Where is the good body of empirical evidence for that?
When Mark says:
“….and in every case of Steve Short’s disagreement, he computed a ratio of A_A/E_D without mentioning how a value of A_A was obtained.It does not seem to an outside reader that such an analysis somehow disproves Ferenc’s claims.”
That is not quite the case. I did not ‘compute’ any such ratios (from 1st principles) – I merely pointed out that the ratio A_A/E_D can be easily extracted (inferred) FROM THE GLOBAL HEAT BUDGETS PUBLISHED BY K&T97, ISCCP-FD, NRA, JRA, Loobe et al 09 and F,T&K09. That is a trivial exercise BTW. This means that the argument is really between Miskolczi and all the above, not between Miskolczi and I. The fact that all those ratios for the various approximate global heat budgets from all those groups only range 1.07 – 1.08 is indeed good evidence that it is not 1.00. Therefore, I note that Mark’s claim that:
“I would take exception to the claim 1.08 is significantly different than 1.00. It may be, but without the added information, claiming so is specious at best.”
is itself a specious argument. I also add that that there are plenty of other instances in the mainstream literature where one can obtain the A_A/E-D ratio for, for example, regional studies. It is impossible to find examples where A_A~E-D within measurement error in other than cloudless cases. I cited examples quite some time back on Niche Modeling. Neither Ferenc nor Zagoni commented. If I (or anyone else interested) had been able to find a body of empirical evidence that A_A~E-D then we would have sat up and taken more notice of Miskolczi’s claims in that regard. But instead we have had to listen to endless unsupported claims over 3 years than only he knows best and no-one else can measure this or are publishing b******t. If that does not fit the definition of idiosyncrasy I don’t know what does.
Ferenc says:
“You have that rather idiosyncratic claim that Ramantahan in 2006 was not aware of the Miskolczi & Mlynczak 2004 Idojaras paper where we wrote on page 238 ….”
The very easy reply to that is that Ramanathan and Inamdar did not cite the Miskolzi and Mlynczak 2004 nor did they give any fundamental ‘proof’ that it should be 1/3 – presenting it an an empirical fact only.
Ferenc says:
“The referred equation is g=(tau+exp(-tau)-1)/(tau+exp(-tau)+1). Since
g(tau=1.87)=0.338, I take Ramanathan’s measured global average g=1/3 as the empirical proof of my theory.”
The very easy replies to that are:
(a) the clear sky g is only known to about 0.33±0.02 or so (the exact value of the error is not important) as there are numerous difficulties with defining precisely a clear sky extreme experimentally – visually or otherwise.
(b) it is an exceedingly tiny curiosity that the value 0.338 = tau+exp(-tau)-1)/(tau+exp(-tau)+1) when tau = 1.87 given that there has been no general acceptance of any proof that g = tau+exp(-tau)-1)/(tau+exp(-tau)+1) nor that tau = 1.87.
When Ferenc is invited back to an annual Heartland Conference to present significant new real world data that supports his ‘theory’ e.g. consistently declining humidity in the lower troposphere with rising CO2, and/or I start to hear that reputable sceptics like Lindzen, Spencer, Christy etc are going around saying e.g. yes, g = tau+exp(-tau)-1)/(tau+exp(-tau)+1) etc., etc then I promise to sit up and take more notice.
In a way, there is a good case for saying that Miskolczi really only had (the easier) task of getting such people ‘on board’ with his theory for others to start taking notice. This was ‘first base’ for Miskolczi. He didn’t even get to first base.
Until then, Miskolczi Theory remains in isolation as just a distraction to the body of sceptical science. I’d much rather people paid more attention to more interesting, more recent, empirical or theoretical stuff which is far easier to follows logically like this:
http://www.rocketscientistsjournal.com/2010/03/sgw.html
214#
Steve,
Thanks for the link…Actually my Su=OLR/f equation tells that there is no AGW and the Sun or other astronomical reasons are behind any long term changes in Su. I am patient enough, and will wait until you understand.
In the planetary greenhouse effect you know everything if you know tau, or A_A or S_T. Mark is right. All those groups should say something about how they got it. The K&T ‘ad-hoc’ method is not good eough. It can not be measured, so what is their A_A?
“(b) it is an exceedingly tiny curiosity that the value 0.338 = tau+exp(-tau)-1)/(tau+exp(-tau)+1) when tau = 1.87 given that there has been no general acceptance of any proof that g = tau+exp(-tau)-1)/(tau+exp(-tau)+1) nor that tau = 1.87.”
This equation for g works also for the Mars…There are no clouds there and the tau is totally different…
By the way, Zagoni was invited to the Heartland Conference this year. Did you hear about that?
Now I guess there is not too much merit in continuing our discussion. Too many side tracks.
Just keep remember that in science, there is no such thing that a new theory is wrong because the others do not like it or do not understand it ( no matter if it is you, Lindzen, Spencer, or other “main stream” scientists.
If Ferenc is right a warming surface will mean an increase in OLR; this is why Lindzen and Choi’s paper is important; it would verify a predicted effect. So to for Paltridge and Soloman’s work on SH; and likewise for NASA measurements of TIOD. As for K&T, hasn’t Trenberth conceded that the K&T cartoon has a number of guessestimates, particularly S_T? Just to be clear, Su is Sg from Fig 1 of the Miskolczi 2007 paper?
216#
Cohenite,
In Fig 1 Su is Sg. It’s meaning is a common surface and surface air temperature…At the air-surface interface the thermal equilibrium is assumed…
217#
Sorry. Correctly Su and Sg are fluxes corresponding to the common surface and surface air temperatures…
Oops, did you hear? Zagoni is not a speaker:
http://www.heartland.org/events/2010Chicago/speakers.html
Oops, did you hear? Zagoni is not on the program (or in a Session):
http://www.heartland.org/events/2010Chicago/program.html
So that’s a rather unique ‘invitation’! Maybe FM means an ‘invitation’ like in the sense that simply anyone in the world can apply to attend and be confirmed while the attendance limit is not yet reached?
Cohenite:
“If Ferenc is right a warming surface will mean an increase in OLR; this is why Lindzen and Choi’s paper is important; it would verify a predicted effect.”
Aw come on! Whose leg are you pulling? Where does this shonky “if Ferenc is right” stuff come from? What ‘predicted effect’? You really have to do your science homework a lot, lot better than that Anthony!
There is simply no need for OLR to going up (in absolute terms) with rising Tsurf (and it doesn’t) if rising Tsurf:
increases moist convection (via ET) by comparison with dry convection (AS IT DOES); hence
increases cloud cover (AS IT DOES); hence
increases Bond Albedo (AS IT DOES); hence
increases the realization of latent heat (rain/ice) at altitude (AS IT DOES).
You should know better than most that Miskolczi had absolutely nothing mathematically useful to say about moist and dry convection, the relationship (if any) between Tsurf, cloud cover and albedo. Miskolczi was not interested one iota in any of this stuff which he stashed all away in a brain dead throwaway ‘K’ term, having no interest in non-radiative matters whatsoever.
Which of course is the heart of the matter.
There is absolutely no need whatsover for OLR to go up in absolute terms as Tsurf rises (and in fact it just doesn’t occur) .
BUT THERE IS a need for the ratio OLR/ASR (where ASR = Absorbed Solar Radiation) to go up, because that is how the globe then cools (due to increased albedo) as it tries to return to radiative equilibrium. You clearly haven’t yet even read Jeff Glassman’s stuff (yet still content to promote the Miskolczi stuff) – shame on you.
So here is a little surprise for you. This little spreadsheet took me all of 5 minutes to knock up (with a beer in one hand too).
Out of the following 7 well known ‘global heat budgets’ i.e. ISCCP-FD, NRA, T,F&K09, K&T97, Loeb et al 09 ‘old’ estimation, Loeb et al 09 ‘optimal’ estimation, and JRA some 6 out of the 7, excluding JRA are compatible with the notion of a rising OLR/ASR ratio with increasing Albedo (hence increasing cloud cover) with an Rsquared of 0.82. Only JRA seem to have got their sums wrong and gone a bit overboard(too much OLR for too little Albedo).
https://download.yousendit.com/bFFOcHBOWkJqV0R2Wmc9PQ
Therefore, don’t you think it would be much fairer to say that “If Kiehl, Trenberth, ISCCP-FD, NRA, Loeb et al are right a warming surface will mean an increase in OLR/ASR”? and I’m only being half flippant here.
Mate, you loosely toss off credits where they simply ain’t deserved. Lindzen and Choi would cringe. I cringe.
Cohenite:
“If Ferenc is right a warming surface will mean an increase in OLR; this is why Lindzen and Choi’s paper is important; it would verify a predicted effect.”
There is simply no need for OLR to going up (in absolute terms) with rising Tsurf (and it doesn’t) if rising Tsurf:
increases moist convection (via ET) by comparison with dry convection (AS IT DOES); hence
increases cloud cover (AS IT DOES); hence
increases Bond Albedo (AS IT DOES); hence
increases the realization of latent heat (rain/ice) at altitude (AS IT DOES).
Miskolczi had absolutely nothing mathematically useful to say about moist and dry convection, the relationship (if any) between Tsurf, cloud cover and albedo. Miskolczi was not interested one iota in any of this stuff which he stashed all away in a throwaway ‘K’ term, having no interest in non-radiative matters whatsoever.
Which of course is the heart of the matter.
There is absolutely no need whatsover for OLR to go up in absolute terms as Tsurf rises (and in fact it just doesn’t occur) .
BUT THERE IS a need for the ratio OLR/ASR (where ASR = Absorbed Solar Radiation) to go up, because that is how the globe then cools (due to increased albedo) as it tries to return to radiative equilibrium. You clearly haven’t yet even read Jeff Glassman’s stuff (yet still content to promote the Miskolczi stuff) – shame on you.
So here is a little surprise for you. This little spreadsheet took me all of 5 minutes to knock up (with a beer in one hand too).
Out of the following 7 well known ‘global heat budgets’ i.e. ISCCP-FD, NRA, T,F&K09, K&T97, Loeb et al 09 ‘old’ estimation, Loeb et al 09 ‘optimal’ estimation, and JRA some 6 out of the 7, excluding JRA are compatible with the notion of a rising OLR/ASR ratio with increasing Albedo (hence increasing cloud cover) with an Rsquared of 0.82. Only JRA seem to have got their sums wrong and gone a bit overboard(too much OLR for too little Albedo).
https://download.yousendit.com/bFFOcHBOWkJqV0R2Wmc9PQ
Therefore, don’t you think it would be much fairer to say that “If Kiehl, Trenberth, ISCCP-FD, NRA, Loeb et al are right a warming surface will mean an increase in OLR/ASR”? and I’m only being half flippant here.
Please don’t toss off credits where they simply ain’t deserved. Lindzen and Choi would cringe. I cringe.
Did you hear? Zagoni is not a speaker:
http://www.heartland.org/events/2010Chicago/speakers.html
Did you hear? Zagoni is not on the program (or in a Session):
http://www.heartland.org/events/2010Chicago/program.html
So that’s a rather unique ‘invitation’! Maybe FM means an ‘invitation’ like in the sense that simply anyone in the world can apply to attend and be confirmed while the attendance limit is not yet reached?
221#
Steve,
Like all the time, you did not want to read what I wrote. I did not write he is a speaker. I wrote he was invited.I have seen the invitation e-mail from Heartland, and the allocated time for his talk. Why Zagoni did not accept it is a different matter. If you are curious ask him….
219#
Steve,
“So here is a little surprise for you. This little spreadsheet took me all of 5 minutes to knock up (with a beer in one hand too).”
You may line up with R. Pierrehumbert, Gavin Schmidt, and the other Supermen.
It took me ten years to compute the correct clear-sky tau. What you can do in radiatiative physics in five minutes probably does not worth to look at, although, it is still possible that you have something revolutionary to say.
(Especially about the Heartland conference…)
“Please don’t toss off credits where they simply ain’t deserved. Lindzen and Choi would cringe. I cringe.’
Please feel free to cringe. The Earth-atmosphere system still will maintain its optimal energy minimum state, it does not need the permission from you, or Lindzen, or Obama or IPCC, and it will not follow the prescribed behavior of the mighty GCM’s , or the skilled radiative budget estimates (without proper LW transmitted flux density computations) of your favorite groups.
Irrelevant difference. You did not measure it, and did not provide any proof that anybody else did measure it. Miskolczi claimed it was not measurable, and you provide a reference in which it is inferred. Explain to me how that disproves his claim it is not measurable?
It is not specious at all. You can’t use the terms “inferred,” and “approximate” while making claims about significance without providing additional information. Simply stating that 1.08 is near the value that others approximate is not sufficient to meet this burden, particularly since the term “appproximate” is involved. Plain old statistics here, that is all.
There was no argument, just a point that you need to back up your statistical claims with… actual statistics (not that the term “significance” really means anything without context anyway).
Mark
Hehe, shouldn’t be a comma after “inferred” above… it started out a longer list but the third term got cut.
Mark
Just to get all our lovely acronyms in sync first up:
ERB = Earth Radiation Budget (definitely not to imply a Balance) – right?
Not to be confused with the March 2000 – May 2004 CERES Earth Radiation Budget Experiment – right?
GMST = Global Mean Surface Temperature – right? This would be at the Global Mean Cloud Cover (GMCC) – right? And at a Global Mean Bond Albedo (GMBA) – right?
But this not necessarily a state of actual Global Heat Balance – right?
Don’t forget the all important ET (EVAPOTRANSPIRATION) and LH (LATENT HEAT) – the BIG ONES that YOU forgot, yeah?
Depending upon who you are in the warmist science camp the global heat imbalance (heating = OLR – ASR) at the present GMCC and GMBA might range from about -0.9 – -2.1 W/m^2.
In the attached spreadsheet it is about -1.5 W/m^2 at GMBA = 0.300 and GMCC = 66.5%.
Yes, it does show a rising GMST but not by much over a typical cloud cover range of (say) from about 61% (A = 0.280) (Row 7) to about 78% (A = 0.340) (Row 27). For a reasonable surface emissivity of 0.997, actual Tsurf would rise from about 14.52 C to about 16.78 C (Column AE).
BUT rising Tsurf increases ET which increases cloud which increases albedo (as Jeffrey Glassman clearly points out and YOU didn’t). At the same time the ratio OLR/ASR is rising due to the increasing REALIZATION of LH.
This is the first KEY POINT.
BUT WHEN the system decays back to a global heat balance of Pin = Pout, i.e. according to the simple well-known heat balance formula I posted in The Air Vent #207 above, the subsequent Tsurf would then range from about 16.54 C (at cloud cover ~61%; A ~0.280; g ~0.396) down to about 13.78 C (at cloud cover ~78%, A~0.340; g~0.421).
This is the 2nd KEY POINT
I have highlighted those rows for you in a lovely pink color.
So as Jeffrey Glassman rightly pointed out, NOT YOU Ference, rising Tsurf (due to increasing GHG) increases ET which increases cloud which increases albedo and latent heat release which then cools the planet as the system goes back to a radiative balance AT THE NEW ALBEDO. This is the fast response.
IMHO the slower long term one (which reduces CO2 sensitivity) is mostly increasing GHGs cause increased oceanic cyanaobacterial and land plant growth which increases CCN production which accelerate cloud formation (and the rate realization of Latent Heat as rain/ice).
BTW, just for your interest, in Column S, I have also tabulated the ‘consensual’ OLRs which would apply if OLR/ASR = 0.6856 exp(1.2397A) which is a (R^=0.82) line of best fit through 6 of the 7 published ERBs (refer Book1.xls).
As you can see, it produces OLR numbers very close to the OLRs predicted by my crude spreadsheet model except for the clear sky end (where I have assumed A = 0.068).
As you well know, the major difficulty in computing OLR is at the clear sky end where there is always more uncertainty in S_U, surface emissivity and surface albedo (from dry aerosols, high seasonal effects on vegetation, ice/snow cover etc). So the assumed mean surface albedo of 0.068 in my little model is very approximate and intended only to apply to cloudy systems (rather than as an accurate reflections (ha!) of the clear sky surface albedo.
However, for an A = 0.068 my very crude spreadsheet model still give a clear sky S_U of ~370 W/m^2, a clear sky S_T of ~100 W/m^2 a clear sky tau of ~2.39 (please note), a clear sky g of 0.30 (‘King’ Ramanathan et al say 0.33) and a clear sky G of ~111 W/m^2 (‘King’ Ramanathan et al say 131 W/m^2).
The actual real mean clear sky albedo is probably more around 0.10 – 0.14.
So, what am I saying about the ‘bottom line’ here as the Americans might say?
IMO the ‘bottom line’ is that it is now crystal clear your arcane model completely ignored and failed to explain mechanistically simply how the generation of cloud (via ET) by a rising surface temperature synchronously increases Albedo and increases OLR/ASR due to increased Latent Heat release (and the fraction of that escaping TOA).
Subsequently, the system moves back to radiative equilibrium as it must (sure – I’ll agree with you that your model ‘explains’ that in a sense) which produces a lower Tsurf.
Ferenc – you got so excited about the chicken you failed to accurately describe the egg – or vice versa (and thereby left your audience behind).
Welcome to ‘Sunshade Earth’!
https://www.yousendit.com/download/OHo3a3NlYStGOFR2Wmc9PQ
226#
Steve,
“Ferenc – you got so excited about the chicken you failed to accurately describe the egg – or vice versa (and thereby left your audience behind).”
First there is the warm surface which radiates, then there is the atmosphere which partly absorbs this radiation, then the greenhouse effect comes (and then the government with its AGW and carbon tax).
Now smart Steve why do not you tell us how you, Lindzen, K&T, or anybody can get the accurate absorbed surface radiation (A_A)? Apparently not your cyanaobacteria but A_A is the only crucial point in the AGW debate. Can you measure it or compute it correctly (maybe in five minutes with or without a beer) ?
Or you may give us references of published acurate global averages of A_A (or tau), preferably from Lindzen, Ramanathan, Ohmura, Lorenz, Kiehl, Pierrehumbert, Schmidt, Fu, or even from LBL giants at AERI or GFDL…
You must understand that talking about A_A=E_D requires A_A. When I first computed it 10 years ago the NASA people were quite surprised, and tried to force me to accept, that the true A_A must be computed from their measured AQUA or CERES window radiation. I showed them that this is possible only with extensive parametrizations based on theoretical computations.
The problem here is that once you acknowledge that A_A=E_D then the AGW will be in ruins (together with the IPCC and carbon trade).
“So, what am I saying about the ‘bottom line’ here as the Americans might say?”
I think the ‘bottom line’ in greenhouse science not yet reached, and still there is a very long way to go. By the way, did you ask Dr. Zagoni about his recent Heartland invitation?
Re: cohenite (May 8 08:58),
It depends on what you mean by saturation. If you mean that the total radiative forcing will stop increasing at some concentration of CO2, then no it won’t saturate at any level that is likely to be reached in the future or has been reached in the past. There are lots of weak lines on the wings of the CO2 band at 667 cm-1 and as the concentration increases, they start to become important and the width of the band increases.
OTOH, if you mean that the optical depth is very large near the center of the band and the percent absorption is greater than 99.9%, then yes that’s true. That’s also the reason that CO2 is major contributor to the magnitude of the ‘greenhouse’ effect. The surface sees emission from the atmosphere in the CO2 band at a brightness temperature very close to the surface temperature. But because temperature declines with altitude and the peak emission to space doesn’t happen until the percent absorption drops to 50%, the brightness temperature of the CO2 band observed from space is about 220 K. Emission over the rest of the spectrum must increase to achieve approximate balance which can only happen by an increase in temperature.
228#
DeWitt,
“Emission over the rest of the spectrum must increase to achieve approximate balance which can only happen by an increase in temperature.”
Not true DeWitt. Why are you so sure? This sounds like Lindzen…
Do you know, that in the real atmosphere the IR tau is decreasing with increasing temperature? Do you know that any change in the amount and vertical (or meridional) distribution of other GHGs can easily compensate your approximate radiative imbalance?
Ferenc:
If, as you say, A_A = E_D not only under clear sky conditions, but under all conceivable conditions of global average cloud cover and hence of global average Bond Albedo (at any one point in time) may I invite you to modify the simple ‘play tool’ Excel spreadsheet which I have posted in #226 in order to demonstrate to us all just how that would lead to a homeostatic condition of automatic CO2 saturation of the greenhouse effect.
The (7) ERBE and CERES-based Earth Radiation Budgets which I have mentioned before, and for which the OLR/ASR ratios of all are listed in the spreadsheet can of course be found in K&T97, Loeb et al. 09 and T,F&K09 etc.
I’m sure you are very familiar with those papers.
You would be free to modify the spreadsheet as you wished and to modify the terms and their explanations on the left hand side where I have listed them as you wish.
For my part, I would be happy to accept that A_A=E_D on the basis of your long, intimate experience of atmospheric radiation physics if you could show in relatively transparent terms how that stabilizes the world’s climate.
This would also give us all a simple, well known logical platform (MS Excel), which many are familiar with, upon which to see how the elements of your Theory fit together to produce that stabilization.
Over to you?
Steve Short:
If I read all the above correctly. You and the rest were advised to stop being a believer and start doing science. The closest any one has come to understanding what was said was JAE. Your mentioning K&T reduces your credibility.
230#
Steve,
Although I do not have excel and I am not familiar with spreadsheets, I shall be happy to go through your work – if you make it available in a simple text file…
My first question:
in 207# You say that:
“Tsurf^4=(1-A)[C/(4σ(1-g))]
This means that the Bond albedo, together with solar irradiance and the greenhouse effect, directly controls the Earth’s temperature. Global warming would result if either A decreased or g or C increased.”
Let us put this into a more convenient flux form: Su(1-g)=So(1-a). I do not think that this is a functional relationship among the variables, and can be interpreted as you said above. Since (by definitions) g=(Su-OLR)/Su, a=(So-Fo)/So, this equation is independent of the Su and So and it is just stating that OLR=Fo, or let us say (after K&T) 235=235 wm-2. To me this is simply the energy conservation principle and not suitable to infer Su. What you say? And what it means “IF repeat IF the planet is in radiative equilibrium, Pin=Pout, then we have….” ?. Climate is about long term average quantities..the OLR must be equal to Fo (or ASR in your terms).
Re: Ferenc M. Miskolczi (May 11 14:01),
I was going to say something, but then I remembered the adage attributed to Mark Twain: “Never argue with a fool; onlookers may not be able to tell the difference.”
Re: Ferenc Miskolczi #232
“Although I do not have excel and I am not familiar with spreadsheets, I shall be happy to go through your work – if you make it available in a simple text file… ”
What can I say but ….. TOTALLY STUNNED!!!!!!
A middle-aged physical scientist! Ex-NASA! In the year 2010 – only some 27 years after the release of Lotus 123? Turning a spreadsheet into a text file…..!
I thought the former acolyte Jan Pompe was pulling my leg way back on Niche Modeling when he said much the same thing.
So what about solving matrices in LBL codes? What about Jacobian arrays solving finite difference/finite element formulae e.g. in GCMs? What about the 77 year old Jeff Glassman, 30 years with Hughes Aircraft Corporation discussing the fine points of cell formulae?
I give up. This is hopeless.
So fittingly preceded by #231 too (;-) Mark Twain we honor you.
CO2 is an infrared absorber, as the lead article demonstrates.
But most of the projected future warming is expected by IPCC to come not from CO2 itself (or other GHGs), but from assumed net positive feedbacks from water vapor and clouds.
Measuring LW radiation tells us only a part of the story regarding cloud feedbacks. Do low level clouds increase with higher surface temperature, thereby increasing SW reflection and acting as a “natural thermostat”? Both the observations by Spencer et al. and of Lindzen and Choi seem to point into that direction.
Then there is the question of water vapor. Does it follow the Clausius-Clapeyron equation in goose-step as the surface temperature warms? Short-term studies seem to show an increase in water vapor content, although some studies show that this is not enough to maintain constant RH, as assumed by the IPCC models. But the NOAA record shows a decrease not only in RH, but also in SH (atmospheric water vapor content) over the long-term period, at the same time as both CO2 and temperature were increasing. [See plot].
It is easy to simply say that the NOAA record must be wrong and radiosonde sensors were much too inaccurate, etc. But this is basically a cop-out.
Yes. CO2 is a greenhouse gas. But what will be the real role of water (as vapor, liquid droplets in low level clouds or ice crystals in high level clouds) with warming surface temperatures? I believe the answer to this question is still wide open.
Max
234#
DeWitt, Steve,
“So fittingly preceded by #231 too (;-) Mark Twain we honor you.”
Mark Twain is right but you are not.
You did not notice, that I am not arguing with you people? Instead of reading and trying to understanding things, you started to argue with me, based on your ancient view of greenhouse theory.
DeWitt, when I am writing: “Do you know, that in the real atmosphere the IR tau is decreasing with increasing temperature? Do you know that any change in the amount and vertical (or meridional) distribution of other GHGs can easily compensate your approximate radiative imbalance?”
Here I do not mean to argue, these are straightforward questions reflecting my curiosity.
Steve, I am jobeless from 2006 and have no resources to by MS Office to read your artwork. And I am a living Dinosaur and do not want to know Excel. If you wish, we may switch to Fortran or Matlab or other macro languages – as I did with your old frend Jan Pompe when things became more complex…
“I give up. This is hopeless.”
Steve, now you are right, let it be. I am out.
Ferenc
I’m 61 and have been a physical scientist (chemothermodynamics, physical chemistry, geochemistry etc) since 1972 (about 65 peer reviewed papers, 3 book chapters, 2 patents). Also 11 years in an Australian Govt. nuclear research agency and 3 years in a Swiss one. So my posted name links to tell exactly who I am – nothing to hide.
I too am another ‘living dinosaur’ who can do Fortran, Matlab, Mathematica etc. When I got started it was punch cards on an IBM 370!
But there is no need to switch to these – especially when blogging with a mix of people from all walks of life.
A robust spreadsheet is all that is needed to test Earth Heat Balances and basic ‘what if’ scenarios. These have been in existence as a powerful basic tool for about 30 years (e.g. since Visicalc)!
Most people with a reasonably good education can use/read them.
It tells me a lot that after 30 years of the use of spreadsheets as the most basic tool for data analysis statistics and manipulation of arrays and matrices through much of our society you still can’t use one.
It is thus ‘artwork’ only to your very strange perception.
Sure, if it makes you both feel good you can switch to Matlab with old friends like Jan Pompe when things get really obscure – I have already seen just how obscurantist it can get – and how little it achieved over 3 years now.
After Jan you would be the only physical scientist I have ever found in a 35 year career who can’t use a spreadsheet. That would probably be the case for almost very physical scientist who reads this blog.
That is why Twain applies.
Re: manacker (May 12 06:45),
Yes, pretty much. But we can put some constraints on the problem. Increasing CO2 should make it warmer than it would have been. A very large negative feedback leading to no effect seems just as unreasonable as a large positive feedback leading to a climate sensitivity of greater than 5 C/doubling. A range of 0.75 to 2.2 C/doubling, i.e. the IPCC range divided by 2, would be in better agreement with the observed data absent the aerosol fudge factor used by the modelers.
Why is a large negative watervapor feedback unreasonable?
Jeff ID:
Because the Earth would be at least 35°C cooler?
Garrick
Not really.
The combined natural water GH effect (est. at 20-25°C) really has nothing to do with the natural CO2 GH effect (est. at 5-7°C), i.e. there is no conclusive evidence that it is a “positive feedback” to warming from CO2.
Max
DeWitt Payne
This might well be so, if we assume that the unusually high level of solar activity had no significant warming impact over the 20th century (as IPCC does). The recent superparameterization studies on clouds have concluded that the 2xCO2 CS is somewhere around 1.5C (i.e. the middle of your range).
Spencer et al. (or Lindzen + Choi) might have it a bit lower, based on physical observations, but your range sounds plausible, based on all the latest data out there.
Max
Re: Jeff Id (May 12 11:17),
Either you assume that there’s some magical mechanism where a large negative feedback starts at ~300 ppmv CO2 or you have to assume that it applies to all CO2 concentrations. We know there’s no mechanism that keeps the planetary temperature or better, heat content, constant. It’s bounded almost certainly but not constant. It’s been both much colder and much warmer than today over the last 100 million years. Saying that doubling CO2 from pre-industrial levels will have no effect when we are reasonably certain from RTE calculations that it does make the surface warmer than it would be otherwise, and by just the right amount to account for current temperatures, is not reasonable IMO.
Ice/albedo alone is not sufficient to account for the glacial/interglacial temperature change. If you say that warming from more CO2 will make more clouds, reducing the effect of CO2, then you also have to say that lower temperature means less clouds and lower albedo and once again, you probably can’t get to glacial conditions.
An excerpt from my post 33 in this thread.
H20, is peculiar, it is a very light gas, but yet a very heavy liquid, and then a lighter solid.
Elsewhere physicists say CO2 (gas) has a very high specific heat content, yet
chemists say their mass equations work with CO2 having a very low heat content. ?
In short, what “we” know CO2 does in a laboratory, ain’t necessarily what it does in the real world mixed atmosphere.
Indeed, it appears to do the exact opposite.
Quite confusing really….
Dr. Miskolczi,
A few bad statements have been made by people who should know better.
Science is all about investigation and a sense of “not knowing.” It drives people to not cite what somebody said 100 years ago or 10,000 years ago (argument from authority). I’m no specialist in the field of radiative physics. But I do know this: Better people than some who have posted here couldn’t hold your dirty jock. I thank you for being so patient with them.
Now I will post this. It brings back fond memories, although a few folks here don’t remember. OK, here it is:
Where is the science?
Does this remind you of anything?
“From his work with rotary magnetic fields, Tesla devised a system for generation, transmission, and use of AC power. He partnered with George Westinghouse to commercialize this system. Westinghouse had previously bought the rights to Tesla’s polyphase system patents and other patents for AC transformers from Lucien Gaulard and John Dixon Gibbs.
“Several undercurrents lay beneath this rivalry. Edison was a brute-force experimenter, but was no mathematician. AC cannot be properly understood or exploited without a substantial understanding of mathematics and mathematical physics (see AC power), which Tesla possessed. Tesla had worked for Edison but was undervalued (for example, when Edison first learned of Tesla’s idea of alternating-current power transmission, he dismissed it: “[Tesla’s] ideas are splendid, but they are utterly impractical.”[3]). Bad feelings were exacerbated because Tesla had been cheated by Edison of promised compensation for his work.[4][5] Edison later came to regret that he had not listened to Tesla and used alternating current.[6]”
Thanks, Dr. Miskolczi, for remaining a scientist. There are not many of them around now.
Kirk
It is simply not a sustainable or sane argument to suggest that any single scientist, including one who left NASA 4 or 5 years ago (for whatever reason), can be the sole repository of what we should know about (or how we should measure) any single parameter such an ‘A_A’ or an ‘E_D’ or any other data part of global or regional radiation budgets.
This is a field in which 100s if not 1000s of scientists work, where the literature goes way back, is voluminous and is by no means monolithic or blinkered in its thinking. Painstaking is the most appropriate adjective.
http://eosweb.larc.nasa.gov/HPDOCS/projects/rad_budg.html
By the same token, there are rigorous, respected, sceptical scientists such as Roy Spencer, John Cristy, Lindzen etc who are comfortable working within the body ALL those data sources and actively publishing their interpretations in the cutting edge literature.
They get my respect.
DeWitt #243
“Ice/albedo alone is not sufficient to account for the glacial/interglacial temperature change. If you say that warming from more CO2 will make more clouds, reducing the effect of CO2, then you also have to say that lower temperature means less clouds and lower albedo and once again, you probably can’t get to glacial conditions.”
DeWitt, it is quite easy to show that under cloud free conditions and current Milankovitch conditions i.e interglacial (TSI ~1365.5 W/m^2) that a full non-equilibrium shift (maximal growth of cloud cover and Bond albedo) from clear sky conditions (g~0.33) to total cloud cover (g~0.46) will depress surface temperatures from about 19 – 20 C to about 9 – 10 C.
This is already about the ballpark range between average peak and trough interglacial/interglacial mean global equilibrium temperatures.
This just serves to highlight the fact that a fairly small change in TSI (or more especially average ASR at 60 N due to the Earth’s tilt) under the Milankovitch oscillation is easily sufficient to initiate glaciation. This is why precisely why the last 17 – 19 or so interglacials have been so so short and their (17 – 19) glacials been so long.
It is easy to be tipped into an ice age – much harder to be tipped into a super greenhouse. That is why the latter have been so rare (thus far). The latter requires something else to ensure persistent low cloud cover e.g. a sustained insufficiency of biogenic CCNs (e.g. Kump and Pollard, 2008).
Re: Steve Short (May 12 22:40),
I’ll sing my song again. We aren’t tipped into glacial periods. Glacial is the current norm. How anyone can look at the Vostok ice core record and think anything else is beyond me. It’s as obvious as the fit of South America to Africa. The Milankovitch cycles, if they are indeed the cause, tip us temporarily out of the glacial. Some sort of amplification ensues, the temperature spikes and then decays back to glacial again. The flatness of the Holocene is, IMO, due to the interruption of the cycle by the Antarctic Cold Reversal which led to the Younger Dryas cooling in the NH. Meltwater pulse 1A may have had something to do with it too. As a result, the peak temperature was not as high as the Eemian and hasn’t decayed as fast. It’s possible that human land use changes associated with the invention of agriculture played a part as well.
Gentlemen,
Re 219
I was invited to Heartland, Miskolczi was not. I asked the organizers to pass my time-frame to him. They didn’t answer.
Re 247
Most of the concerns here is going on whether Ed/Aa=1. A common literature value is 1.08 , Miskolczi has given an explanation for the difference (emissivity, anisotropy). It might be enough to start thinking on the physics behind. Try to imagine what the heated Earth is doing in its cold space environment, what GHG’s are doing with this heat radiation, and what physical principles could drive these processes. If you could make one step forward here, all what remains will be much easier.
Best regards, Miklos Zagoni
Correction:
Sorry Dr Short, your #230 was meant.
Miklos Zagoni
And, of course, the ratio is the opposite (I must be a bit tired).
DeWitt Payne #248
I agree with what you say. However, I would point out the following:
Maximal temperatures in most Pleistocene interglacials were not much different from the present although sea levels were very often up to 10 m higher than present – how to explain that?
It is often stated (AGW school) that modern CO2 levels are unprecedented for at least the last million years i.e. by comparison with Pleistocene interglacials. I am not so certain off this claim as the time resolution of ice core slices may have been overstated and the ubiquity of higher sea level stands than now would tend to cast doubt on the claimed ice core resolutions. There is also some issue about the roles of aqueous diffusion and co-deposited calcium carbonate/dissolved CO2 dynamics in ice as it packs down – noting that polar ice is usually laid down in a high wind context and carbonate-secreting cyanobacteria (‘coccolithophores’) are ubiquitous in polar region seas.
Almost all interglacials were characterized by multiple peaks – typically 2 – 3. Notwithstanding the development of agriculture (which should have increased pCO2 and reduced land-based biogenic CCN production) why should we think that the present interglacial (Holocene) cannot have multiple peaks and that the present trend is not somehow the start of a natural 2nd Holocene peak, regardless of any CO2 level driver?
Lots to think about, not enough known with any great certainty/precision. Here’s hoping this century teaches mankind more humility and reduces it’s hubris.
Miklos
I really do appreciate the civility of your comments.
As noted, I would like to see A_A/E_D = 1.00 rather than ranging 1.00 – ~1.10 as seems to be the case.
So, we all know that A_A = S_U – S_T = upwelling LW radiance from BOA absorbed in the atmosphere.
But what exactly is E_D (the downwelling LW to BOA)?
This is the really interesting question is it not?
One reason for the establishment of my spreadsheet ‘play tool’ was that I ‘discovered’ over two years ago that, over the entire albedo range from clear sky (say A~0.125) to a total cloud cover (say A~0.415):
E_D ~ (1-k)(F+A_A+LH+SH) ~0.675(F+A_A+LH+SH)
where k ~0.375
and
F = SW absorbed in the atmosphere
LH = Latent Heat (realized i.e. absorbed in the atmopshere)
SH = Sensible heat (realized i.e. absorbed in the atmosphere)
In other words, all 4 fluxes absorbed in the atmosphere (F, A_A, LH and SH) seem to subsequently partition themselves roughly equally (as LW IR) ~62.5% -> TOA and ~37.5% -> BOA.
This then gives OLR ~ S_T + k((F+A_A+LH+SH) of course.
This simple picture enables one to reproduce the outcomes of most published modern global heat budgets if one then adds in the relatively trivial relationship that Cloud Cover (CC) ~ (A-0.068)/0.35 – this being similar to empirical relationships estblished in the 1980s – 1990s.
For example this gives:
a clear sky A_A/E_D ~ 1.027, a clear sky S_U ~ 380, a clear sky Tsurf ~ a clear sky G ~ 114 and a clear sky g ~ 0.30.
Such a simple model both enables us to ‘scope out’ just how a
(1) (low cloud) rising Tsurf generates cloud and hence both Albedo and an increased OLR/ASR (global/regional) non-equilibrium state (through an increased LH portion escaping -> TOA)
(2) which state then subsequently ‘decays’ back to (global or regional) radiative equilibrium as the increased Albedo and atmospheric/surface heat loss leads (radiatively) to a reduced Tsurf.
But it also seems to me that such a simple model also enables us to explore just what likely the consequences of a universal A_A = E_D (from clear sky through to total cloud cover) would be.
I tried hard to get Ferenc to look at this approach to showing/ maybe convincing me or anyone else that (perhaps) A_A=E_D but he doesn’t understand spreadsheets which was a very great surprise.
Regards
Steve
Sorry missed out …a clear sky Tsurf (before heating) ~9 – 10 C….
Oops again (I am tired too)!
In other words, all 4 fluxes absorbed in the atmosphere (F, A_A, LH and SH) seem to subsequently partition themselves roughly equally (as LW IR) ~62.5% -> BOA and ~37.5% -> TOA.
Re: Steve Short (May 13 04:47),
Step 2 is where you lose me. Is Tsurf new greater than or equal to Tsurf original? If it’s equal, then what happens to the lapse rate? I don’t see how the increased cloud cover can be maintained at the same surface temperature as before. Or putting it another way, I don’t see how you can justify having 100% of the increased surface heating be carried away by convection (latent and sensible) alone.
Dear Dr. Short,
Your calculation is flawless. If your k=0.375, then
Ed=0.625(F+K+Aa) (let be K=LH+SH), then taking 0.625~2/3-2/50~16/24-1/24=5/8, and taking (for the moment) Ed=Aa (and hence Eu=F+K), you will have 3Ed=5Eu, as at Miskolczi. The difference is less then 1/25.
So I think you see this right. But let me suggest here a bit different optics.
Let’s start from Aa=Su-St and OLR=Eu+St, and clear sky case.
The question is, whether Aa Ed.
If AaEd, then Aa=Ed+X, where X is some radiation upward from the atmosphere.
As OLR is kept fixed by the incoming available SW Fo (for a given albedo), our formula for OLR is now:
OLR=St + (Eu-X) + X.
The difference of Aa and Ed would diminish the upward atmospheric radiation. (We have fixed Aa, St, Su, OLR here, it is just a thought experiment for different Aa-Ed ratios.)
If you could agree with me so far, I explain this further next time, answering the question: What would be the consequence of this?
Thank you for your attention.
Yours sincerely,
Miklos Zagoni
Oops, the system ate some of my signs.
Here:
he question is, whether Aa Ed.
If AaEd, then Aa=Ed+X, where X is some radiation upward from the atmosphere.
I wrote whether Aa is less then, or equal, or grater then Ed. I have written AaEd.
And I wrote also: If Ed>Aa would be the case, it would be a real surprise in global average, as we think the energetic source of the downward atmospheric (back-) radiation is the presence of GHG’s in the air.
But what if Aa>Ed ? In this case, Aa=Ed+X, …. (and hence the text is OK.)
Let’s see the signs….
Still not perfect…. But I hope it is at least understandable now. Dr Short please check it back.
Miklos
245#,249#
Kirk and Miklos: Thank you very much for your comments.
I am only a “mere Miskolczi” to Steve, and I do not know what you think about expert Dr. Steve Short and deWitt, but be careful with them. When Steve is saying (202#)that:
” the true cloud free LW IR tau is probably closer to about 2.3 and is nowhere close to 1.87 ”
Unfortunately he is not saying how probable his tau=2.3 is. Now, according to T,F&K09 (Steve’s “cutting edge literature”) the clear sky tau is tau=-log(40/396)~2.3 with 1.42 prcm h2o column amount. It seems that the cutting edge tau and Steve’s spreadsheet tau is about the same.
With a quick check on the real clear sky tau I can say this:
The NOAA global annual average h2o in the last 61 years is 2.6 prcm.
My LBL code with 2.6 prcm global average h2o gives tau=1.869 . Here LBL means that this is computed using only first principles and monochromatic radiative transfer.
With the NOAA 288.9 K global average surface temperature this tau gives the clear-sky transmitted flux density: S_T=395exp(-1.869)=60.9 Wm-2. (If I remember well you confirmed a similar value with the CERES team, Kiehl, Kratz and Loeb.)
Since tau depends mostly on h2o, apparently Steve is saying that
tau(1.42 prcm_h2o)=2.3 > tau(2.6 prcm_h2o)=1.8 <——
that is, H2O increasing, tau decreasing. This reminds me to the GCM feedback processes where the enrgy is not conserved. Something must be wrong with Steve's spreadsheet (or the "cutting edge literature"). But at least Steve had fun. Maybe DeWitt also had, I am not sure.
Miklos, think of Mark Twain, do not waste time. I computed this tau for NASA while I was there and it semms they (the CERES team) are using it, but still they do not know how to compute. (It is not the direct output from HARTCODE.) This tau=1.87 was obtained from a different data base many years ago, and was first published in Miskolczi and Mlynczak 2004.
And here comes the belief in Steve's "cutting edge literature" and competence. Who is right Steve, KT, IPCC or "mere Miskolczi"? Or 20 Wm-2 difference in S_T (or A_A)does not matter in AGW? Only the 0.024 changes in tau due to stupid CO2 doubling and the related ~ 1.3 Wm-2 canges in A_A is important?
One more thing. Steve was so kind to give us his credentials. His kind of people always end up questioning the authority and qualifications. (You can see his "Heartland invitation" comments here and there). At some other blogs I was already blamed not having proper training in atmospheric radiative transfer. My answer to them is repeated here:
I have an MS. Degree in nuclear physics, a Ph.D. in astronomy, another Ph.D. in earth sciences, a degree in software engineering, a degree in philosophy and 30 years of work experience in atmospheric radiative transfer, radiation measurements and remote sensing. I worked at several places: ICTP Italy, Paul Scherer Institute in Switzerland, University of Maryland, Raytheon and NASA in USA, ect. This should be sufficient to develop a decent view of global warming.
Ferenc
249#
Miklos,
As I see Steve has a wish list:
“Miklos…
As noted, I would like to see A_A/E_D = 1.00 rather than ranging 1.00 – ~1.10 as seems to be the case.”
I made a HARTCODE run for Bill Kininmonth half a year ago to see if there are observed A_A=E_D cases. Here is one, maybe you can feed this into his spreadsheet. There are many more cases if you need.
====
% HARTCODE numerical accuracy is set to four significant digits.
Ta=0.3475
tau=1.057
su=198.0000 w/m^2
st=68.80355 w/m^2
ed=129.1985 w/m^2 su-st=ed
————————————————————————–
Antarctic sounding, June 21, 1984 Latitude: -67.40 deg, Longitude: -45.51
Column format, 40 levels: Pressure (mb) Temperature (K), h2o(g/g), o3(g/g)
—————————————————————————
1013.00 243.15 0.23323E-03 0.37433E-07
955.00 248.95 0.37257E-03 0.39929E-07
900.00 247.25 0.31290E-03 0.43220E-07
848.00 245.45 0.29939E-03 0.46512E-07
800.00 242.95 0.27455E-03 0.49803E-07
724.00 243.65 0.28754E-03 0.55250E-07
651.00 242.45 0.22771E-03 0.60017E-07
584.00 237.45 0.15105E-03 0.64166E-07
525.00 233.55 0.10168E-03 0.68353E-07
471.00 229.65 0.68661E-04 0.74819E-07
423.00 225.24 0.44966E-04 0.83468E-07
380.00 220.65 0.29252E-04 0.92116E-07
342.00 215.85 0.18104E-04 0.10068E-06
307.00 211.35 0.11255E-04 0.10933E-06
276.00 208.75 0.81577E-05 0.14540E-06
248.00 206.85 0.59122E-05 0.19005E-06
222.00 207.45 0.42849E-05 0.23469E-06
200.00 208.05 0.31057E-05 0.27891E-06
161.90 205.95 0.20000E-05 0.41917E-06
131.20 203.85 0.20000E-05 0.65859E-06
106.20 201.65 0.20000E-05 0.95690E-06
86.07 200.45 0.20000E-05 0.15530E-05
69.70 199.85 0.20000E-05 0.22839E-05
56.50 197.55 0.20000E-05 0.34192E-05
45.70 196.25 0.20000E-05 0.46132E-05
37.00 194.76 0.20000E-05 0.58860E-05
24.80 197.50 0.20000E-05 0.83177E-05
16.60 205.70 0.20000E-05 0.10530E-04
11.11 215.08 0.20000E-05 0.11976E-04
7.40 228.77 0.20000E-05 0.12500E-04
4.90 240.78 0.20000E-05 0.12377E-04
3.33 247.54 0.20000E-05 0.10934E-04
2.23 251.71 0.20000E-05 0.95008E-05
1.50 251.95 0.20000E-05 0.80791E-05
1.00 250.94 0.20000E-05 0.66280E-05
0.55 249.58 0.20000E-05 0.40383E-05
0.30 241.67 0.20000E-05 0.22458E-05
0.17 232.97 0.20000E-05 0.15898E-05
0.09 223.23 0.20000E-05 0.99378E-06
0.05 214.22 0.20000E-05 0.64399E-06
249#
Miklos,
It seems Steve has a wish list, see 253#:
“Miklos
I really do appreciate the civility of your comments.
As noted, I would like to see A_A/E_D = 1.00 rather than ranging 1.00 – ~1.10 as seems to be the case.”
About half a year ago I run a sounding case for Bill Kininmonth, who has the same problem. Here is the data.You may feed this into Steve’s spreadsheet…
There are many more cases if you need.
Ferenc
=====
% HARTCODE numerical accuracy is set to four significant digits.
Ta=0.3475
tau=1.057
su=198.0000 w/m^2
st=68.80355 w/m^2
ed=129.1985 w/m^2 su-st=ed
————————————————————————–
Antarctic sounding, June 21, 1984 Latitude: -67.40 deg, Longitude: -45.51
Column format, 40 levels: Pressure (mb) Temperature (K), h2o(g/g), o3(g/g)
—————————————————————————
1013.00 243.15 0.23323E-03 0.37433E-07
955.00 248.95 0.37257E-03 0.39929E-07
900.00 247.25 0.31290E-03 0.43220E-07
848.00 245.45 0.29939E-03 0.46512E-07
800.00 242.95 0.27455E-03 0.49803E-07
724.00 243.65 0.28754E-03 0.55250E-07
651.00 242.45 0.22771E-03 0.60017E-07
584.00 237.45 0.15105E-03 0.64166E-07
525.00 233.55 0.10168E-03 0.68353E-07
471.00 229.65 0.68661E-04 0.74819E-07
423.00 225.24 0.44966E-04 0.83468E-07
380.00 220.65 0.29252E-04 0.92116E-07
342.00 215.85 0.18104E-04 0.10068E-06
307.00 211.35 0.11255E-04 0.10933E-06
276.00 208.75 0.81577E-05 0.14540E-06
248.00 206.85 0.59122E-05 0.19005E-06
222.00 207.45 0.42849E-05 0.23469E-06
200.00 208.05 0.31057E-05 0.27891E-06
161.90 205.95 0.20000E-05 0.41917E-06
131.20 203.85 0.20000E-05 0.65859E-06
106.20 201.65 0.20000E-05 0.95690E-06
86.07 200.45 0.20000E-05 0.15530E-05
69.70 199.85 0.20000E-05 0.22839E-05
56.50 197.55 0.20000E-05 0.34192E-05
45.70 196.25 0.20000E-05 0.46132E-05
37.00 194.76 0.20000E-05 0.58860E-05
24.80 197.50 0.20000E-05 0.83177E-05
16.60 205.70 0.20000E-05 0.10530E-04
11.11 215.08 0.20000E-05 0.11976E-04
7.40 228.77 0.20000E-05 0.12500E-04
4.90 240.78 0.20000E-05 0.12377E-04
3.33 247.54 0.20000E-05 0.10934E-04
2.23 251.71 0.20000E-05 0.95008E-05
1.50 251.95 0.20000E-05 0.80791E-05
1.00 250.94 0.20000E-05 0.66280E-05
0.55 249.58 0.20000E-05 0.40383E-05
0.30 241.67 0.20000E-05 0.22458E-05
0.17 232.97 0.20000E-05 0.15898E-05
0.09 223.23 0.20000E-05 0.99378E-06
0.05 214.22 0.20000E-05 0.64399E-06
#260
Quick reply due to work time constraints.
I do not think the clear sky S_T is anywhere near 60.9. Your memory is wrong. As my little spreadsheet shows (if you had bothered to look at it) I think it is in the range 90 – 100. This has always seemed to me to be consistent with Miskolczi/Zagoni? Let me know what you think.
However, I do know that you also consistently claimed the average cloud cover S_T (A~0.3) is ~ 60. This I do not see and think it is ~40 (similar as computed from F,T&K09) or probably even a bit less i.e. it is in error by at least +20 – +25. This is the source of of the tau issue.
I think the problem is that your theory does not deal with LH and SH and the opening and closing of the cloud-based window to LW IR transmission accurately enough. It always seemed to me to not be such a big step to fix those issues.
I am not questioning your credentials – they are impeccable.
I was only questioning why, after spreadsheets have been an essential basic tool of science for ~30 years you somehow cannot do them?
When you turn a spreadsheet into a text file the formulae are lost and only the values remains. The beauty of a spreadsheet is that you can change any formulae and/or any constant you wish and see how the altered outcomes ripple though the whole matrix. Can’t do that with a text file table of fixed values – it is just an inert thing
The silly insinuation that you cannot afford MS Office is just not credible – why do you bother with such childlike assertions? You can use any spreadsheet for a trivial cost e.g. the excellent German SoftMaker Office costs something like EUR 60. It has always been so.
Interesting about your background. I was at Uni. Bern 91 – 92 and Paul Scherrer Institute 93 – 94 (nuclear waste repository engineering-related studies for NAGRA) und sprach Deutsch auch.
As you know I am a sceptic – not an AGW fanatic. Can we please get away from the fear and paranoia (same as on Niche Modeling) and just do science? Miklos’s comments show clearly that there is no need for such stuff.
DeWitt Payne #256
“Step 2 is where you lose me. Is Tsurf new greater than or equal to Tsurf original? If it’s equal, then what happens to the lapse rate? I don’t see how the increased cloud cover can be maintained at the same surface temperature as before. Or putting it another way, I don’t see how you can justify having 100% of the increased surface heating be carried away by convection (latent and sensible) alone.”
As I see it the cloud window opens which allows greater surface heating (Tsurf increases and ET builds up). This then leads (in a regional sense which is then out of thermodynamic equilibrium with the whole globe) to increasing moist convection but decreasing dry convection (noting dry convection occurs more or less in between cloud and hence moist convection and dry convection move in different directions in relation to cloud cover).
However, ultimately, the resultant cloud cover reaches some maximal level during which a certain amount of rain/ice forms releasing latent heat (LH), of which ~37.5% radiates through TOA and ~67.5% radiates back to BOA.
Nevertheless, the spreadsheet model shows that, provided OLR ~ S_T + 0.375(F+LH+SH) where S_T is the LW IR from BOA transmitted to TOA (in the cloud free window), F is the incoming absorbed SW, LH is realized latent heat from the clouds, and SH the sensible heat from the residual dry convection, then
(1) OLR/ASR has increased while there is increasing cloud cover (exporting more heat off the planet than would apply under an equilibrium, fully heat balanced situation); and
(2) Albedo (A) has increased.
The very next thing that happens is that, at some point the process must halt (for any one of a number of reasons – including meridional heat transfer) and the situation must then ‘decay’ back towards the equilibrium (balanced) situation because:
(1) there is no more LH to be realized (i.e. the clouds have fully ‘rained out’ or crystallized); and
(2) the increased A has already reduced ASR back to OLR (or lower) and hence the rate of Tsurf increase has slowed to zero and then reversed.
So this combined heat pump and atmospheric dehumidifier (the 1st tow engines; refer Pauluis, 2005) has finally stalled.
As the clouds dissipate, must Tsurf continue to fall because S_T and the dry thermals increase (this is the 3rd sensible heat engine) until the local equilibrium balance is once again restored.
The equilibrium balance is, by definition, where Pin = Pout and hence Tsurf^4=(1-A)[C/(4σ(1-g))]. I agree with FM that g must have a fixed value at that point – I am just not convinced by his argument that it should be 0.333.
If you look at my spreadsheet you will see that, as a function of albedo (or cloud cover) the two Tsurfs (non-equilibrium and equilibrium) run (in relation to Albedo and Cloud Cover) in reverse order to each other.
This is Jeff Glassman’s important point, i.e. albedo (aka cloud cover) must, for a period, go up with increasing (non-equilibrium) Tsurf for the whole ‘Sunshade Earth) system to work.
Note that we must not forget any cloud-based sunshade itself is still radiating all the time (to BOA and TOA).
DeWitt, beyond reading Jeff Glassman’s latest monograph (I have a .pdf if you want me to upload it) may I suggest you get a copy of the ‘Red Book i.e. Non-equilibrium Thermodynamics and the Production of Entropy. Life, Earth, and Beyond. (Axel Kleidon and Ralph D. Lorenz, Eds.) Springer, 2005.
Re: Steve Short (May 13 20:19),
I’ll reduce my question to the basics. If we take the current value of surface radiation (Su?) from Trenberth et. al. of 396.1 W/m2 as the reference point for 380 ppmv CO2 (or whatever it was), what will it be after everything settles down if CO2 is increased to 760 ppmv? What I would really like to see is the complete energy balance numbers. Does your spreadsheet do that?
Re: Steve Short (May 13 20:19),
I just looked that up on Amazon. Sorry, not going to spend $149 on a book with only two reviews, one a detailed one star review that tears the book to shreds.
DeWitt Payne and Steve Short
With all due respect for spreadsheet forecasts, atmospheric CO2 is at 390 ppmv today. Over the past 50 years it grew at a compounded annual growth rate (CAGR) of 0.04%, and over the most recent 5 years at 0.042%.
If we assume it will continue to grow at the most recent CAGR, it will take 159 years to reach 760 ppmv (i.e. by year 2169).
So many unforeseen things will happen between now and then (new technologies, natural climate changes, etc.) that it does not make much sense to guesstimate what the GH warming would be from this increase, even if the spreadsheet were perfect.
Max
Re: manacker (May 14 15:48),
I think you added a decimal point, shouldn’t be 0.4% CAGR (slightly less than 2 ppm/year) not 0.04%.
Fossil fuel consumption has been increasing approximately linearly. That means that cumulative emissions must be increasing as at least t^2. In fact, if you fit the MLO data, the best fit I found was an exponential function with a time constant that increased linearly. If that were to continue (highly unlikely IMO) the concentration would be 780 in 2100. The A1F1 family of IPCC SRES has CO2 at 970 ppmv in 2100 (complete fantasy) and the somewhat more likely A1B is 723 ppmv. If I were a betting man and was likely to live long enough to collect, I’d say we won’t see 600 but we probably will see a doubling from the pre-industrial level of ~280 ppmv. I picked 760 not because I think we will get there but because I want to see the calculated effect of doubling CO2.
I’ve looked at Steve’s spreadsheet and it doesn’t look like it will do what I want. At a glance, it seems to be full of questionable assumptions like the ratio of outgoing long wavelength radiation to space at the top of the atmosphere to down welling long wave radiation to the surface at the bottom of the atmosphere is constant. The relationship of cloud cover to surface temperature seems to be somewhat circular, not to mention that it’s probably not linear except over a narrow range of temperature. The relationship of cloud cover to albedo cannot possibly be valid near 100% cloud cover. not to mention that the difference between high, middle and low altitude cloud cover is completely ignored.
There are a couple of interesting looking web interfaces for playing with the carbon cycle per IPCC – Archer’s here – unfortunately not as clear graphics as I would like. You could play with the IPCC emission scenarios using the applet available here .
DeWitt Payne #265
For a present K factor of 0.377, the non-equilibrium and equilibrium Tsurfs balance out at about 15.21 and 15.25 C respectively (say) and OLR is about 237.5 W/m^2. Tsurf should probably be a little lower but my surafce emissivity is arbitrarily set at 0.997. Optimal Albedo is about 0.304 and optimal cloud cover about 67.4%.
For a new K factor of 0.370 the non-equilibrium and equilibrium Tsurfs (same emissivity) balance out at about 15.17 and 16.86 C (say) and OLR is about 233.5 some 3.8 W/m^2 lower i.e I have assumed doubling of CO2 would reduce OLR by 3.8 W/m^2 (hence changed K and g factors). Optimal Albedo remains about 0.304 and optimal cloud cover remains about 67.4%.
My model’s sensitivity to a doubling of CO2 to 760 ppmv is therefore about 16.86 – 15.17 C = 1.69 C say 1.7 C. Due to tweaking issues with my model I’d say that is good to about ±0.2 – 0.3 C.
I have already explained above to Miklos what the K factor is (note he like the 0.375 which is what I said it appeared to approximately be.
Gotta go now – it is Saturday morning here – nice things to be done!
DeWitt
“Sorry, not going to spend $149 on a book with only two reviews”
Steve might correct me but I think every paper in that book also appears in the peer reviewed literature so it depends on what you think your time is worth because you can buy the book or spend hours looking for the same material elsewhere and pay $30 + per paper from the Journals’ sites.
Re: Jan Pompe (May 14 19:42),
From the review on Amazon.com:
Just because something appears in the peer-reviewed literature does not make it worth reading, much less spending $150 on it.
DeWitt Payne #272
Another quick comment on a simply glorious Sydney Saturday (to be treasured).
DeWitt, Jan is correct and also that is a deeply eccentric Amazon review by some antediluvian still lost way back at Prigogine (who started all this, admittedly). Even our Garth Paltridge is a contributor for example – the most mature climate scientist I’ve ever listened-to.
If you don’t believe me, just Google something like Maximum Entropy Production or MEP. You will find that there are simply hundreds of papers on the subject and Lorenz (Ralph not the older E) and Axel Keleidon are leading researchers in the field. There is a whole group led by Klaus Friedrich at the Max-Planck Intsitut in Hamburb near the Uni of Hamburg-Harburg (where I taught some summer seminars in the late 90s) which is deeply involved in MEP work and have a very nice Earth climate simulator used to test MEP-based ideas.
Incidentally – getting back to my little spreadsheet model it predicts a (Earth) balanced heat budget equilibrium sensitivity to the doubling of CO2 of ~1.7 C which I think is reasonable. But what it also shows is that if the strength of the (non-equilibrium) ‘engine’ shedding heat by increasing OLR/ASR and cooling by increasing albedo increases accordingly i.e. by maintaining the ratio ~0.375: ~0.625 for the partitioning of absorbed energy between TOA and BOA (as it might) then the sensitivity would be less (than 1.7 C).
How much less I can’t yet work out and don’t have the time or expertise as I running a consultancy (with some other grumpy old men). It hinges closely on the timescales (non-equilibrium equilibrium) involved. But as I am an expect in aqueous solid/liquid chemothermodynamics and hydrometallurgy this concept comes quite easily to me. BTW at the other end of the scale I suppose you have read the paper by Gavin Schmidt and others in Nature Geoscience about the supposed very high longer term CO2 sensitivity ‘add on component’ derived from paleoclimatic studies. If that is correct we (and the planet) are truly doomed.
I find it very difficult to get across that, at the core, I agree strongly with what Miskolczi/Zagoni are saying about homeostasis about a GHG near saturation. It is just that I am not convinced FM has a tight handle on how it should all work (and don’t accept his surface flux math) and IMHO the answer probably lies in what the MEP people are saying. Also, as I and FM are very probably both Aspies, you are quite free to make of our curiously antipathetic dynamic what you will (;-)!
DeWitt Payne #272
“Bottom line, this book is an utter disaster and should be pulled by the publisher and libraries until it minimally contains a very explicit warning or can be re-edited to eliminate the deep technical errors, especially Dewar’s derivation, as well as other errors like the editors’ elementary misunderstanding of Prigogine’s minEP and corrects the remarkable lack of legitimate attributions to the people who have really pioneered and developed this work. Of course that would make it an entirely different book.”
Uh oh! The reviewer is one Bill Watts, as in:
http://www.cowboybillwatts.com/
Wild Bill is it seems an admirer of someone called Rod Swenson with numerous web sites who claims to have discovered MEP way back in 1988, as in:
rodswenson.com/
Rod Swenson write papers (in obscure epistemiological journals) with amazing language like this:
“Boltzmann’s attempted reduction of the second law to a law of disorder became widely accepted as the second law rather than simply an hypothesis about the second law, and one that we now know fails. It became the apparent justification from physics for solidifying Cartesian incommensurability and establishing the view of the two incommensurable rivers-the “river” of biology, psychology, and culture, or the epistemic dimension of the world characterized by intentional dynamics and flowing up to increasingly higher states of order, versus the “river” of physics flowing down to disorder. Such a view is entirely inimical to a science of ecological relations, since, as noted above, it is precisely through the interface of these two rivers that these relations occur, and if the interface is incommensurable then the relations are effectively prohibited, or at best, incomprehensible.”
and this little gem….
“It is just this reconciliation that sets the tolerance space with respect to uniting the otherwise incommensurable rivers and providing a principled account of the epistemic dimension and the constitutive ecological relations that instantiate it.”
Yes sir – you sure blew it there DeWitt ……but also made my day!!!
http://en.wikipedia.org/wiki/Wikipedia:Articles_for_deletion/Law_of_maximum_entropy_production
DeWitt Payne
Yes. That’s a typo. I used 0.42% compounded annual growth rate (the CAGR we have seen over the past 5 years).
And with this rate we would theoretically reach the 760 ppmv level by year 2169.
Carrying this from the ridiculous to the absurd, IPCC has several “scenarios”, most of which are totally unrealistic. The top two get us to CO2 levels that are physically impossible to ever reach, based on the carbon contained in all the optimistically estimated fossil fuels on this planet. The next three have CO2 growing at 0.65%, 0.80% and 0.86% CAGR; extremely unlikely, in view of increasing scarcity/cost, pressures to conserve energy/reduce fossil fuel use and likely new technological developments.
Using a 2xCO2 scenario (starting with today) for “convenience sake” is nice, but does not really tell us anything practical, which is also the basic problem of the IPCC projections.
One could conceivably imagine a CO2 level of 560 ppmv (or 2x the estimated “pre-industrial” level of 280 ppmv) by year 2100, which would represent a CAGR continuing at the present rate, but even this is dicey.
Remember that back in 1860 some one calculated that Manchester would be covered in 2 meters of horse manure by 1920, due to the rapidly increasing number of horse carriages.
Theoretical physics and spreadsheets are nice (climate models are even nicer). But they are all totally worthless as far as long-range climate projections are concerned, due (among other things) to the unforeseen outliers.
For a good treatise on why this is so, read “The Black Swan”, by Nassim Taleb.
Max
DeWitt Payne
Earlier you stated:
This makes sense to me (average of around 1.5C), based on the model results on clouds using superparameterization plus some of the latest physical observations on cloud feedbacks.
With a 2100 CO2 level of 560 ppmv (2x the estimated “preindustrial value”) this means we should have seen a total equilibrium anthropogenic GH warming of 1.5C, of which we have theoretically seen roughly 45% to date, leaving us added GH warming of around 0.8-0.9C from today to year 2100, all other things being equal.
This is obviously no big deal (and all other things are most likely NOT equal).
Max
Re: Steve Short (May 15 03:28),
I didn’t write that review, so I don’t see how I “blew it”. Aside from that bit of snark, your comment puts the review in context and gives good reason to ignore it. I still don’t think I’ll spend $150 though. The positive review mentioned Gaia and that doesn’t give me a lot of confidence either.
I’ve been doing some calculations with MODTRAN to look at tau and other factors. It does look like A_A and E_D are very close, but A_A is larger for every case but sub-Arctic winter. Since MODTRAN, as implemented by Archer, only covers the range from 100-1500 cm-1, the ratio of A_A to E_D is underestimated. S_U will increase more than S_T and E_D if the full spectral range were to be included. An upper bound on the ratio can be calculated using the Stefan-Boltzmann equation with an emissivity of 0.98 as used in MODTRAN and assuming that the total transmitted radiation, S_T. doesn’t change from that calculated by MODTRAN. That gives a ratio of 1.11 for every case but sub-Arctic winter. Put in a cloud layer and the ratio at the surface is almost exactly one. That really isn’t surprising considering that you have two essentially parallel planes with near unit emissivity/absorptivity. The bottom of the cloud layer can’t be warmer than the surface, but it can’t be much colder either.
Tau is also underestimated using only MODTRAN data for similar reasons. Tau for tropical atmosphere, clear sky is 1.93 and is probably more like 2.0. If you look at the atmosphere above the top of the clouds, there is a lot of room for an increase in tau, which would reduce heat loss from the cloud tops resulting in a higher temperature. For the 1976 standard atmosphere with the first cumulus cloud option (base 0.66, top 2.7 km) at an altitude of 3.5 km, tau is about 0.8 when I assume that A_A and E_D at that altitude are equal.
Re: Steve Short (May 15 00:49),
If I’m not going to pay $149 for a book, I’m even less likely to pay $32 for one paper.
There were lots of things that were different 3Mya besides the atmospheric CO2 concentration. The Isthmus of Panama hadn’t closed yet for one. That made a huge difference in ocean circulation and meridional heat transfer. One hundred or even one thousand years of high CO2 aren’t going to melt Greenland and Antarctica and we certainly don’t have 1,000 years of fossil fuels by any rational estimate. While there may be 5,000 GT of fossil carbon left, most of the easy stuff is already gone and before too much longer, certainly less than 1,000 years, the EROEI is going to decline sufficiently that fossil carbon will no longer be a primary energy source.
Using global average cloud cover and albedo in your model is a bad idea. Surface albedo and insolation vary a lot by latitude. Albedo graph based on data from Petty. Albedo near the South Pole is greater than 0.7 and greater than 0.5 near the North Pole so cloud cover would probably reduce albedo there rather than raise it. One of the problems with climate models is that they generally have the wrong amount of clouds in the wrong place.
Re: DeWitt Payne (May 15 18:33),
Free version here.
Re: Nick Stokes (May 15 19:18),
Either they’ve taken it down or the link’s broken. I get a 404 error.
Re: DeWitt Payne (May 15 19:50),
Went back to the original WUWT article and found a working link to the paper at http://www.leif.org
Thanks.
Since absorption is essentially 100% near the surface from 5 to 100 cm-1 and for wavenumber greater than 1500 (I used 3000 cm-1 as an upper limit), I can use the Planck function to calculate the flux that isn’t calculated by MODTRAN. Also, by the same logic, the average transmittance times the surface emission calculated by MODTRAN does give S_T. It turns out that A_A/E_D calculated using 100-1500 cm-1 data is quite close to that calculated using total emission using Stefan-Boltzmann and an emissivity of 0.98 for the surface and the adjusted E_D. A_A will be slightly larger than E_D unless there’s a temperature inversion, sub-Arctic winter, e.g. That means tau for tropical atmosphere clear sky is 1.9985 and 1.437 for the 1976 standard atmosphere. Since the transmittance of clouds is zero, which makes tau undefined (ln(0) does not compute), I don’t see how one can calculate a planetary average tau for the surface to space except as some sort of meaningless (IMO) mathematical construct.
DeWitt #278
I don’t think it is being snarky pointing out to you that, when you have quoted extensively from a highly negative Amazon review (implying it was valid comment) you haven’t bothered spending a minute or two on Google satisfying yourself that the review was legitimate. If you had done so you would have found it was submitted by an odd ball embedded in some looney backwater of pseudo-science. Your mistake.
I too, as have very many others, have done a lot of playing around with Archers’s MODTRAN and did so long before I started the spreadsheet play tool. As you say, since MODTRAN, as implemented by Archer, only covers the range from 100-1500 cm-1, the ratio of A_A to E_D is underestimated.
“Put in a cloud layer and the ratio at the surface is almost exactly one. That really isn’t surprising considering that you have two essentially parallel planes with near unit emissivity/absorptivity. The bottom of the cloud layer can’t be warmer than the surface, but it can’t be much colder either.”
You are confused there. While E_D increases with increasing cloud cover, globally the ratio A-A/E_D also increases with increasing cloud. A_A/E_D is not always equal to ~1.10 – in fact it only attains ~1.10 at about a 100% cloud cover – below that it ranges from ~1.00 through an average of about 1.06 – 1.08 for most (mean global albedo/mean global cloud cover ranges) conditions. As Miklos pointed out a value of 1.08 is often assumed (about the global mean). It is quite easy to verify these numbers by reference to the literature.
“Using global average cloud cover and albedo in your model is a bad idea.”
This is utter rubbish. The spreadsheet is a simple 1D global model like many before it. Even Miskolcozi Theory is a simply 1D model of sorts. M Theory actually suffers terribly from not having dealt with albedo and cloud cover in a more direct fashion – the author, as clever as he is, did himself an enormous disservice thereby being then reduced having to ascribe global homeostasis to mysterious effects such as an inverse relationship between pCO2 and lower troposheric specific humidity (not happening).
It just so happens that you can take 6 out of the 7 global radiation budgets of recent years i.e. K&T97, F,T&K09, Loeb et al 09 (both budgets), ISCCP-FD and NRA and when you plot OLR/ASR against Albedo (A), for an albedo range from 0.293 – 0.315 you will get OLR/ASR = 1.2728A + 0.6126 R^2 = 0.82 or perhaps better OLR/ASR = 0.6856exp(1.2397A) R^2 = 0.82. The only odd one out is the JRA recalc of the CERES data and they must have made big mistake somewhere because they end up with a far too low albedo of 0.279 and hence a far too high ASR of 244.5. I think you really need to go away and at least read F,T&K09 and Loeb et al 09 very carefully. While you are at it read Pinkster et al, 2005 too.
Putting aside further secondary issues of what sort of cloud and their level, put simply cloud cover e.g. as tabulated by NOAA etc., etc., is the major determinant of albedo over most of the globe because most cloud, globally, is low and middle level cloud. I also note that you had previously observed that virtually no LW IR penetrates cloud. This also tends to invalidate your subsequent more recent statement above “…and assuming that the total transmitted radiation, S_T doesn’t change from that calculated by MODTRAN.”
Including global cloud cover and albedo in any simple 1D global model is critical.
DeWitt Payne #279
“If I’m not going to pay $149 for a book, I’m even less likely to pay $32 for one paper.”
Uh, Nature Geoscience is fully online…..
And this is always worth a read (or re-read):
http://climateaudit.org/2008/01/14/from-lacis-et-al-1981-to-archer-modtran/
Re: Steve Short (May 15 23:04),
It’s fully on line but it’s not free, or not free to everybody. When I go here, it says I need to pay $32 to get the full text version.
A 1D model of the planet is a toy model. It may be useful for illustration but it will always be fundamentally incorrect.
As far as albedo and cloud cover, the average of the product of insolation and albedo by latitude and corrected for area is not equal to the product of the average albedo and average insolation in any case where the albedo change is not uniform with latitude, which will almost always be the case in the real world.
I said that the 1.11 figure was an upper limit for the ratio and an overestimate, not the correct value.
I’ll consider buying the book if you can tell me three things I would learn about Physical Meteorology that the meteorologists don’t already know.
DeWitt #287
“A 1D model of the planet is a toy model. It may be useful for illustration but it will always be fundamentally incorrect.
As far as albedo and cloud cover, the average of the product of insolation and albedo by latitude and corrected for area is not equal to the product of the average albedo and average insolation in any case where the albedo change is not uniform with latitude, which will almost always be the case in the real world.”
I don’t really want to get into pious exchanges over semantics. By a 1D model I actually meant an average global energy budget (in this cases using a spreadsheet) which apportions the various fluxes appropriately. This is no different to K&T97 and other global budgets right through to F,T&K09 and Loeb et al. 09. So if the 1D term is too simplistic or inaccurate I withdraw it.
At the same time such a model can also be used to look at regional energy budgets – and indeed, in effect, numerous examples appear in the literature in numerous papers. Of course when you do a MODTRAN run with Archer’s (now rather dated) tool you are doing something even cruder.
The major deficiency of such budgets, especially regional ones, is that they have difficulty coping with meridional heat fluxes i.e. winds. Firstly this is probably the major reason why albedo change becomes non-uniform with latitude and secondly, and ironically, that this is one area where the MEP concept has been particularly useful to global climate modeling e.g. the Max Planck Institut’s Planet Simulator GCM.
http://www3.interscience.wiley.com/journal/121377806/abstract?CRETRY=1&SRETRY=0
287# DeWitt
You say:
“A 1D model of the planet is a toy model. It may be useful for illustration but it will always be fundamentally incorrect.”
This is a rather idiotic view. The smaller the dimension of the energy budget model the more real phisics is required to explain. The mighty GCMs with their ad-hoc assumptions and assumed feedbacks are the real and useless toys in the research of the long term climate change. They (on the taxpayers money) struggle to fit their predicted global energy budget components to the zero dimensional real word. Long time ago J. Neumann told us that the fate of the climate is in the behavior of the radiative componetnts at the boundaries. First you must understand the physics of that.
287 De Witt, 288 Steve Short
Have you seen the following
http://hockeyschtick.blogspot.com/2010/05/nasas-earth-energy-budget-contradicts.html
You both appear to be supporters of K&T and F,T&K
Claes Johnson http://claesjohnson.blogspot.com/2010/05/thermodynamics-of-global-climate-2.html
Also makes some observations on the 2nd law of thermodynamics.
Steve is Australia going to experience a cold winter?
Keep healthy and warm.
The evidence is that around the world there are more deaths in winter and in summer
(1) I agree with FM (and DeWitt) that A_A~E-D
(2) I agree with FM that the LW IR tau is 1.871 (such as it is – a point DeWitt appreciates well).
(3) I agree with FM that the average ratio of S_U/OLR under greenhouse saturation conditions is 1.666 (5/3).
(4) I agree with FM that the planet is near greenhouse saturation BUT with the normalized greenhouse factor g only able to range (under a global heat balance condition) from ~0.378 – ~0.405 (both Ramanathan and FM wrong about the clear sky 0.333), averaging about 0.402.
(5) I contend that under clear sky conditions S_T = not only transmitted LW IR BUT ALSO an (absorbed, retransmitted, upwelling) ~37.5% fraction of sensible heat departing TOA. Mistake by FM.
(6) I contend that the planet is rarely at heat balance at any one time but is on balance over the long term due to the dictate of Maximum Entropy Production (MEP) which maximizes internal entropy, including maximizing meridional heat transfer and the production of photoautotrophic (CO2 consuming) and dark decay (CO2 generating) microorganisms.
(7) I contend that so-called paleoclimatic cases of apparent high CO2 sensitivity are mistaken and another major perturbation e.g. high TSI, asphalt and oil volcanoes (yes they do exist), must have applied at the time. There are no reliable, unambiguous proxies for high TSI.
(8) I agree 100% with Jeff Glassman that ‘greenhouse saturation’ is largely all about cloud and albedo.
Keeping on keeping on:
https://download.yousendit.com/OHo1UXV0OW5tUUh2Wmc9PQ
Re: Cement a friend (May 28 09:39),
Oh, please, not another misunderstanding of the Second Law article.
Try reading The Science of Doom on this matter:
http://scienceofdoom.com/2010/05/28/the-first-law-of-thermodynamics-meets-the-imaginary-second-law/
http://scienceofdoom.com/2010/05/21/intelligent-materials-and-the-imaginary-second-law-of-thermodynamics/
http://scienceofdoom.com/2010/05/08/radiation-basics-and-the-imaginary-second-law-of-thermodynamics/
http://scienceofdoom.com/2010/04/05/on-the-miseducation-of-the-uninformed-by-gerlich-and-scheuschner-2009/
There is back radiation from the atmosphere. You can detect it with a $50 IR thermometer. Back radiation doesn’t violate the Second Law. The cooler surface doesn’t warm the hotter surface. The hotter surface loses heat less rapidly.
Post 290 – I think you’ll find that is an old NASA budget.
I am not certain how old it is though (does anyone know please – are there older versions of it around),
it could (possibly) be from as far back as the 1960s.
(Please see the paper in the second link in this post titled
– Greenhouse Effect on the Moon.)
Please see this page last edited in Sept. 2007.
http://eosweb.larc.nasa.gov/EDDOCS/radiation_facts.html
I wondered myself if it was a “new” plot but Mark D at Jo Nova’s blog kindly linked to the above page.
“We” have been discussing it on this thread at GWS.
http://www.globalwarmingskeptics.info/forums/thread-727-page-1.html
It would seem to me that the NASA page above linked to is the transition to a budget that includes “back radiation”,
not a “new” budget that excludes “back radiation”.
This transition was enabled by Gavin’s “trick” or misinterpretation
of radiation intensity as a heat flow as described by Terry Oldberg in Post 13 of this thread,
http://www.globalwarmingskeptics.info/forums/thread-609.html
Excerpt,
” I’ve discovered a diagram that is similar to the Kiehl-Trenberth diagram in an essay
( http://www.realclimate.org/index.php/arc…ple-model/ ) by Gavin Schmidt of NASA-GISS on “the greenhouse effect.”
Like the Kiehl-Trenberth diagram, Schmidt’s diagram confuses the radiation intensity
which the Kiehl-Trenberth diagram calls the “back-radiation” with a heat flux.
By this error, Schmidt creates “the greenhouse effect.” ”
I think that is the more likely context of the plot you mention,
ie,
I could be wrong of course…
292#
DeWitt,
‘Back radiation doesn’t violate the Second Law.’
I am curious if you will ever understand what is the physics behind the E_D=S_U*(1-T_A) relationship….
E_D does not violate the second law, However, you, your government greenhouse effect, the IPCC greenhouse effect and the AGW do violate it.
Post 294.
Ferenc, as you know I have been coming at what you mention from several different angles recently.
As yet I still do not understand how the relationship you mention and E_D does not violate the 2nd law
yet AGW / IPCC, and DeWITT do.
I have an understanding why AGW et al get it wrong, but
I am not sure how the relationship you describe differs.
Obviously my understanding is incomplete at present.
Would you be kind enough to explain to me please, preferably by email.
I’d do a post about it in due course obviously.
#
Dear All,
I made a new attempt to clarify my opinion about AGW – and the Government Greenhouse Effect:
http://multi-science.metapress.com/content/c171tn430x43168v/?p=ad1e44ae55754e548
ae474618bfb4102&pi=8
I hope not everyone is jobless scientist like me, and you may afford the article.
Corrected version of Ferenc’s link.
Or not…
Try this
#296 – would you mind emailing a copy of the paper? I don’t have university style access to these things.
The stable stationary value of the earth’s global average atmospheric Planck-weighted greenhouse-gas optical thickness
Authors
Ferenc M. Miskolczi
Abstract
By the line-by-line method, a computer program is used to analyze Earth atmospheric radiosonde data from hundreds of weather balloon observations. In terms of a quasi-all-sky protocol, fundamental infrared atmospheric radiative flux components are calculated: at the top boundary, the outgoing long wave radiation, the surface transmitted radiation, and the upward atmospheric emittance; at the bottom boundary, the downward atmospheric emittance. The partition of the outgoing long wave radiation into upward atmospheric emittance and surface transmitted radiation components is based on the accurate computation of the true greenhouse-gas optical thickness for the radiosonde data. New relationships among the flux components have been found and are used to construct a quasi-all-sky model of the earth’s atmospheric energy transfer process. In the 1948-2008 time period the global average annual mean true greenhouse-gas optical thickness is found to be time-stationary. Simulated radiative no-feedback effects of measured actual CO2 change over the 61 years were calculated and found to be of magnitude easily detectable by the empirical data and analytical methods used. The data negate increase in CO2 in the atmosphere as a hypothetical cause for the apparently observed global warming. A hypothesis of significant positive feedback by water vapor effect on atmospheric infrared absorption is also negated by the observed measurements.
Apparently major revision of the physics underlying the greenhouse effect is needed.
Anyone for surface (land AND ocean) heat retension…..
Unlike photons, it is both slow enough, and powerful enough to explain most of the observed effects.
#299
Jeff, send me an e-mail to fmiskolczi@cox.net .
I will send you a reprint.
Ferenc
Ah, theory and observations. Now we are getting somewhere.
===============
#
Dear All,
In case you read the
http://multi-science.metapress.com/content/c171tn430x43168v/?p=ad1e44ae55754e548ae474618bfb4102&pi=8
article, there is a typo in page 253. In the 6th line from the top there is a missing hat, ‘^’, from above tau_A.
# Dear All,
Something about the climate science in USA. Here is K. Trenberth view:
>
> I do not have access to this journal but I read the abstract. It is
> unfortunate that rubbish such as this gets published in obscure journals.
> Kevin Trenberth
>
Perfect ground for scientific debate….
Heh, it’s a travesty that they can’t find the missing refutation.
==============
From a Theoretical and Experimental Physicist and designer of Infra-Red Spectroscopy Systems.
Sorry Bubba!
You are wrong.
“. . . outgoing light get’s absorbed and re-emitted . . . ”
It converts by collision with air [mostly di-oxygen and di-nitrigen] rapidly to kinetic energy [heat]. It’s better than 1000 to 1 that the collision occurs before the IR Potential Energy can re-emit a photon. No fancy charts in Wikipedia are going to change that result. One more thing, if CO2 and H2O were constantly emitting IR Photons, would your IR Camera be able to take any pictures other than fuzz?.
No more photonics of CO2 or H2O within inches of the earth surface. If anything it may enhance the surface cooling by a miniscule amount.
Photonics channels are quenched near the ground, the air is mixed by wind and reaches equilibrium with the boundary layer conditions being the rule.
No IR means no Greenhouse Effect, as was demonstrated about 100 years ago when Svante Arrhenius was proposing the silly business in the first place.
Doc
Paul (and Doc) are exactly right. AGW is science fiction. Aside from the minuscule amount of IR just meters above the surface, there is also the problem of the alleged “equality” between incoming & outgoing radiative flux. Obviously, when warming is observed, the incoming must have exceeded the outgoing for some reason… but it is unclear exactly when, because the ocean is a marvelous thermal reservoir.
Incoming energy is confined to 1/2 of Earth’s atmosphere; outgoing energy is actually confined to 1/2 as well, unless one adjusts the measured “incoming” to also account for the outgoing energy on the sunny side. If incoming is “A” and outgoing is “B”, then temperature measured on the sunny side should be the result of A + B, while temperature on the dark side should be just the result from B. Drastically oversimplifying, 1360 W/m2 would be the equivalent of 907 W/m2 incoming + 453 W/m2 outgoing. However, 30% of incoming is reflected without absorption. This gives 408 W/m2 reflected even before night falls. Therefore, 1360 – 408 = 952 W/m2 net incoming energy becomes the equivalent of 635 W/m2 incoming + 317 W/m2 outgoing at the surface.
For those with sufficient background in physics, I would recommend reading an old paper by Yang, Smith & Bartman (1986). They concluded that relative humidity (i.e. water vapor, not CO2) highly changes OLWR flux, and therefore, water vapor is a dominant factor in moderating outgoing IR. No AGW science has come along to challenge YS&B’s conclusions…they are still valid today.
The paper by Yang, Smith & Bartman can be found here:
http://journals.ametsoc.org/doi/pdf/10.1175/1520-0450(1987)026%3C1134%3AAEOLRC%3E2.0.CO%3B2
Reblogged this on emisciency and commented:
Good explanation of how CO2 warms up the atmosphere – more scientific than the “blanket” but still comprehensible.
This is my first time visit at here and i am truly impressed to read
everthing at one place.
To accomplish the plan, the EU wipe out incandescent 5-step:
First environmental protection bills of all, these jobs cannot be outsourced.
‘ Nature is also our editor, and is a good portion of my first twenty
years chasing after that mysterious pulse of the endless so easily found in wilderness and
wild places.
There are a few issues not addressed.
Relative to all the heat presently escaping from earth across the full long wave length spectra, what percentage continues to escape at the wave length that CO2 absorbs? For it is only those remaining photons at that energy level which may still be penetrating the atmosphere and escaping into space, not the percentage of ones already captured, that represents the total additional heat that could possible be trapped by any further increase in CO2. There is diminishing incremental heat capture for each additional unit increase in CO2. That is a vital factor. Once all the photons that tend to be released at the specific CO2 wave length are absorbed no additional heat trapping is possible.
Secondly, it is impossible for earth to radiate away the same amount of energy it takes in from the sun, else we wouldn’t have fossil fuels to power our world today. When we burn fossil fuel we are releasing solar energy trapped and sequestered in the chemical bonds manufactured through photosynthesis. Some amount of the inbound solar energy is converted into work, it takes energy to lift the water from root to canopy, and more still is retained in the molecular structure of the growing vegetation, the future fossil fuel. I do not know what amount of energy this is compared to the entire energy budget, but given the work and carbon based material growth of living organisms, I would never expect a measurement of equal incoming and out going energy.
Take a look at the graph posted in the beginning of this thread that displays the specific portion of the long wave radiation absorbed by Oxygen, CO2 and Water. A few points for thought.
Notice how the plot for CO2 is displaced more to the right with respect to the other gases and the overall total, corresponding to its absorption of the longer wave lengths that comprise the entire spectrum.
Wave length is directly related to energy and energy to temperature. Shorter wave lengths, or higher frequencies, represent more energy. Photons absorbed by CO2 are ones of lesser energy than some of the photons absorbed by both water and oxygen.
This means the graph is a bit misleading. The area under the curve is not in proportion relative to the amount of energy being absorbed based on the frequency and the consequential impact to temperature.
Oxygen absorbs photons of the highest energy and therefore has a greater impact to temperature than CO2.
Now consider this. The production of CO2 during combustion takes existing, airborne oxygen molecules and their shorter wave length absorption, their greater energy trapping effect, and binds 2 of these molecules with carbon into CO2. This process removes oxygen from the air allowing a greater number of higher frequency photons to escape, and adds more CO2 into the air with their lower heat trapping characteristic.
The net effect of combustion and CO2 creation means more higher energy photons escape to offset more lower energy photons trapped. More energy escapes and temps should decrease by reducing oxygen and creating CO2.
Mark,
There is a lot more oxygen in the atmosphere than CO2. 21% as compared to .04% CO2. The effect of a heat trapping gas is logarithmic with respect to changes in PPM and oxygen is pretty saturated so sub percentage fluctuations don’t have much impact on warming.
Thank you for your reply. Yes I understand the logarithmic properties and the relative concentrations of CO2 and O2. Perhaps my question is poorly presented. I will try again.
Regarding the logarithmic issue, this pertains to O2 and to CO2, both are far along their respective curves where equal unit increase have increasingly small increase to heat capture. Not sure relative to each other how these curves would play out, both gases are near saturation, I believe, so changes to either gas would cause small heat trapping impact, but would a decrease in O2, as small as the heat escape increase might be, be greater than the corresponding small increase in heat trapping associated with CO2 gain. In fact, the relative logarithmic positions on the curve is another important factor I failed to consider. But my original point is this.
1. Does the earth radiate heat in the spectra of O2?
2. If point 1 is true, how much of the total band of earth heat release overlaps with the spectra of O2 and, more specifically, in comparison to the overlap with CO2.
3. Understanding points 1 and 2, any photons that are impeded from radiating into space with energy levels/frequency/wave length at the spectra of O2 are going to be of higher energy than the longer wave length photons blocked by CO2, given the longer wave length of CO2 compared to O2 and recognizing that shorter wave length/higher frequency of a particle is directly correlated to higher energy.
4. Given point 3, if a photon of lower energy is blocked by CO2 it would cause a temperature change increase. But that temperature increase would be smaller than any temperature change decrease caused by a photon that may be able to escape into space at its higher energy level due to O2 decrease.
5. Point 4 is looks at the heat impact on a photon unit basis. How many photons may be impacted by reduction of O2 and increase in CO2 would be a function of how much the respective spectra of each gas is overlapped by earths radiation band width and the logarithmic issue. How much heat does earth radiate in the spectra of O2, how much in the spectra of CO2, and both relative to the total heat release band width of earth and their relative logarithmic functions. And critically, O2 traps higher energy photons, CO2 lower energy photons.
6. The result of combustion of fossil fuels is sequestered carbon atoms (in the molecular structure of the fuel) are combined with airborne O2 to create a new molecule of CO2. So, combustion reduces already existing O2 a bit and creates a new airborne molecule of CO2. 1 O2 removed, 1 CO2 gained.
7. Combined point 6 with the issues discussed point 1 to 5,small net heat changes caused by both gases as both have a logarithmic function, but what are the respective functions compared to each other, O2 slight decrease, CO2 slight increase, how much of earths radiation is in the spectra of each gas, and recognizing that the slight decrease in O2 would afford slight increase in the number of photons able to radiate with higher energy levels, whereas the slight increase in CO2 would block more photons from radiating but these photons would be of lower energy levels.
8. All of these issues combined, what is the net impact of energy trapped/radiated? Is it possible that combustion actually affords more energy to radiate to space? That is the question.
Let me see if I can help
1 – Yes figure 3
2 – See figure 4.
3 – yes
4 – yes
5 – Yes
6 – yes
8 – No. Because the concentration levels of the two gasses are so different. Any molecule with an available excitation level of the correct energy will act as a receptor to the a photon of the correct wavelength. There are differences in concentration of available excitation levels based on the vagaries of molecular behavior but since oxygen is 500 times more prevalent, the difference in oxygen concentration cannot possibly make up for the difference in CO2 concentration. Imagine that even if oxygen were 2 or 4 times more likely to “catch” a photon in this long wavelength energy band (which to my knowledge it isn’t), it couldn’t touch a 500X difference in ratio. If that doesn’t satisfy your personal curiosity you will need to look deeper into molecular absorption mechanics. It may give comfort to you that if it were even close this would not have been missed by many who study global warming.
Hello, yeah this paragraph is actually fastidious and I have learned
lot of things from it about blogging. thanks.
If the truth is out there I hope I find it.
My understanding ,for a molecule is:
1. Energy absorbed at lower wavelengths would suggest a greater propensity to affect temperature than those at higher wave lengths
2.The total energy absorbed is more significant when determining whether a molecule has a greater propensity to affect temperature,than whether one molecule or another has an absorption spectrum that overlaps an emission
spectrum to a greater or lesser extent.
3.The solar radiation spectrum and earth reflectance spectrum are not uniform across the whole planet.
4.Concentrations of Co2,H20 ,O3,etc are not uniformly distributed around the planet.
Has anyone analyzed the different molecules and their order of importance to heating,based on items 1&2&3 ?
Apsolut Rubbish.
Can’t resist – What is?
Thanks for sharing such a nice opinion, piece of writing is
nice, thats why i have read it entirely
<<>>
Why should directionality matter?
Wow. What a woeful pile of poo. Co2 does not cause ANY warming. It acts as an insulator so we don’t return to absolute zero when the sun goes down. A portion of the heat it absorbed is returned to earth but it doesn’t make it any hotter. A hot iron in a fire does not make the fire hotter. Also, through ignorance or deception, you fail to mention that the absorption properties of co2 saturate at about 40ppm. This means that 400ppm has no discernable effect over 40ppm.
You also do not take into account that warm air rises helping to move the heat upward toward space, to be replaced with cooler air.
And don’t even get me started on precipitation
JT,
If the heat is returned to Earth, is the Earth warmer than it would be were the heat not returned?
No questions allowed?
Ok, so a day later, let me explain how this will go. I’ve been here many times before.
You will make more ridiculous unsupportable claims. I will doggedly ask basic questions which you cannot answer. IF and it is a capital “IF”, you try to answer, you will dig yourself into a deeper hole. Eventually you will stuff your head into the sand denying anyone might have a better grasp of physics than you and you will go away in a huff.
FYI, in the future, If you don’t have the physics chops to talk about physics, you may want to take it easy with the whole “conclusion” thing.
Oooh! Oooh! I have some questions!!!
The earth has been warmer than this several times. It has had higher c02 levels several times…who saved the earth all those times before you and Al Gore came along? how did they do it?
JT,
I thought you had been around here before. hmmm
Why would warmer Earth mean higher CO2? I certainly haven’t claimed that. You are under some sort of misapprehension about tAV.
Jeff. My claims are supported by science. Yours are supported by computer models. There are computer models that say I am a strapping young wizard, who rides a unicorn that farts fairies… That doesn’t mean it is reality. Convection is real… As are the limits of co2 and it’s greenhouse effect
Climate models have failed. My, and the rest of this god-forsaken rock’s true scientists all know full well that CO2 causes warming — a little at least — and it has literally zero to do with ‘models’.
What we the ‘true’ scientists of the world also know is that it doesn’t appear to be very much warming. Nor does it appear to be a problem. The left wing of the planet has captured the governments of the world and the public mind. This is no fault of my own, nor does it change the simple basic fact that CO2 does cause warming — at least a little.
What I don’t like, are these people who pretend to be scientists, or pretend to have some grasp of it, yet claim CO2 can’t cause warming — cause they are quite ignorant and they are fools. Loud and ignorant are a bad combo. –not that you are one of them.
https://noconsensus.wordpress.com/2015/04/07/thermorons/
Convection is a process which can be increased due to CO2. If we consider an increase in CO2, even a hugely negative feedback from convection, will result in microscopically increased warming.
Convection is not only warming, it is also cooling. increasing convection just increases the process. it still comes to a balance between the heat given off by the planet, and absolute zero of space.
Maybe I am mistaking what your whole point is. it seems like you have gone to a lot of trouble to prove your are right, even though what you are right about seems to be an irrelevant technicality, in the bigger picture… The amount of co2 and it’s effect caused by man is negligible, and the earth is a big boy and it can handle it without a problem…and without Al Gore
Maybe we are both spending too much time preaching to the choir and arguing over minutia. 🙂
Convection is a net cooling process as it moves heat from the lower troposphere upward toward the final emission altitude where the energy is released to space.. Aside from that, you are assuming more correctly about my point, but the minutia as you say are scientific unknowns. It seems like we might have about 1.3 C/doubling of CO2, which is not only NOT dangerous but quite likely beneficial. But science is science and we don’t get to chose what we would like to see.
I don’t believe I am spending too much time on this, I really believe it is important that climate dissent be intelligent and concise in its nature. We must be scientifically accurate, and let the consensus be the unscientific fools.
yes CO2 causes some warming, but earth’s Co2 levels have always been higher than the saturation point . Meaning that the warming properties maxed out long before 400ppm, and long before mankind roamed the earth. All more co2 does is make vegetables grow better… I see what this is…you hate people, and you don’t want them to have vegetables!!!!
Ah, I see now. What you are missing is that warming can never max out. Degree of saturation is easily calculated by a logarithmic equation and while CO2’s effects are reduced, they are still non-zero.
while true, your statement is irrelevant, because, although it may never reach zero, it’s effects become a fraction of a fraction of a fraction of a percent, and the more you add, the more zeros you have to put in front of that fraction of a percent. (and you are talking about .00003% of an effect of a gas that is less than 1% of the atmosphere) You are talking about a fart in a hurricane….a very tiny mouse fart.
From observation, the effect is quite possibly larger than you state. Observations by Nic Lewis show a higher number, but I still don’t believe he has proven your estimate wrong. The oceans can overwhelm the atmospheric temperature changes — without detection by our instruments. They are not good enough!! and this problem is a big deal for climatology.
We simply cannot measure oceans to the accuracy required to really know climate.
Y’all have to remember that the temp data sets used have been “adjusted”. Has anyone tried their studies using raw data and really depending on the law of large numbers??
A rough look at GHGs
If there were a 1 degree change in surface temperature caused by greenhouse gasses, a thumbnail estimate indicates that approximately 0.993 degrees was caused by water vapor, 0.007 degrees was caused by CO2 and 0.00003 degrees was caused by CH4. Human CO2 contribution is 0.0017 degrees per degree above the natural temperature (whatever that is).
GHGs
Water Vapor = 4% of atmosphere
CO2 = 0.04% of atmosphere
CH4 = 0.00018% of atmosphere
Humans contribution of CO2 = 0.01%
Water absorbs 50% more of Earth’s radiated heat than the same amount of CO2; see the explanation at the bottom .
Thumbnail estimate:
What proportion of temperature is contributed by each gas?
GHG total = 4% x 1.5 + 0.04% + 0.00018%= 6.04018%
WV = (4% x 1.5) / 6.04018% = 0.993 degree
CO2 = (0.04%) / 6.04018% = 0.006622 degree
Ch4 = (0.00018%) / 6.04018% = 0.00003 degree
Check:
0.993 degree + 0.006622 degree + 0.00003 degree = 1 degree
Manmade CO2 = (0.01%)/ 6.04018% = 0.00166 degrees
The above is only an estimate and the actual warming from methane would be far less because methane only has a very tiny radiation-absorption-band relative to the other GHGs in the earth’s radiative bandwidth.
Explanation:
Referring to this graph: Google Image:
Atmospheric Transmission.png
CO2 is passive and merely absorbs and re-radiates existing energy it receives; it does not create heat. CO2 only scatters heat. Water-vapor and CH4 do the same thing. If the frequency of scatter is in the sun’s radiation bandwidth, some of the sun’s heat is redirected back into space due to scattering and if the frequency of scatter is in the earth’s radiation bandwidth, some of the Earth’s radiated-heat is redirect back into the atmosphere due to scattering.
As shown in the referenced graph, the absorption frequency bandwidths for CH4 are very narrow and there are only three of them; two of them are outside the earth’s radiative frequency band. The approximate average CH4 atmospheric concentration is 0.00018%. CO2 is well within the earth’s radiative frequency bandwidth and has a wider absorption bandwidth but the concentration is still low at the approximate average of 0.04%. If you look at the water-vapor absorption bandwidth, you will see that it is significantly wider than CO2 and covers some of the same frequencies as CO2 and has many peaks. Some of the narrower water-vapor peaks are in the sun’s radiative bandwidth but the majority of water-vapor absorption bandwidth is in the earth’s radiative bandwidth. Atmospheric water-vapor concentration was estimated by NASA to be approximately 3 to 4% and one water-vapor molecule is 50% more effective at absorbing radiation than one CO2 molecule. There is 100 times more water vapor than CO2 and 27,777 times more water-vapor than CH4.