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Radiative Physics – Yes CO2 Does Create Warming

Posted by Jeff Id on April 19, 2010

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.

Fig 1

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.

Figure 2 - nanometers. 5000 nanometers is 5 microns in Figure 1. 1000 is 1, 2000 is 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.

Figure 3

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.

Figure 4 - no idea who get's credit for this plot

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.

1. RBsaid

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.

2. RBsaid

urk.. are “aware of that as well.”

3. Bregosaid

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.

4. Jeff Idsaid

#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.

5. timetochooseagainsaid

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”.

6. Jeff Idsaid

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.

I think so too.

7. Bregosaid

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.

8. Jeff Idsaid

Faith in a blackbody curve and the absorption spectra of CO2?

as I said before — weird.

9. gallopingcamelsaid

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

10. Jeff Idsaid

#9 Thanks, I was too lazy to look it up.

11. gallopingcamelsaid

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.

12. Gary Psaid

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.

13. Dave Dardingersaid

#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.

14. steven moshersaid

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.

15. kevoikasaid

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?

16. tetrissaid

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?

17. RBsaid

@#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.

18. Carricksaid

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.

19. Chriskafesaid

#11

That song was adopted by the Faculy of Science at Sydney University as the Faculty song.

20. kuhnkatsaid

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.

21. Carricksaid

Tetris:

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?

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?

22. Carricksaid

kuhnkat:

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.

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).

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?

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.

23. gallopingcamelsaid

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.

25. timetochooseagainsaid

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!

27. Billsaid

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.

29. Curieuxsaid

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.

30. scienceofdoomsaid

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.

31. Steve Fitzpatricksaid

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.

32. GregOsaid

#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.

33. Dereksaid

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”……

34. Ausie Dansaid

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.

35. scienceofdoomsaid

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.

36. Ausie Dansaid

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?

37. Geoff Sherringtonsaid

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?

38. Nick Stokessaid

Re: Geoff Sherrington (Apr 20 08:05),
For high optical thickness, the Rosseland approximation to the RTE is the one to use.

39. scienceofdoomsaid

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.

40. Steve Fitzpatricksaid

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.

41. GregOsaid

Thanks scienceofdoom for the patient explanation.

42. RBsaid

#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.

43. JAEsaid

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.

44. Josh Keelersaid

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.

45. tarponsaid

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.

46. Jeff Idsaid

#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.

47. Jeff Idsaid

#45, Adding more CO2 will always cause more warming, but the increases are diminishing as concentrations rise.

48. tarponsaid

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.

49. Dan Hughessaid

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.

50. Andrew_KYsaid

OK

For clarity…

The assertion is not that increased C02 causes Global Warming

The assertion is that increased C02 causes ‘warming’, immeasurable currently.

Andrew

51. JAEsaid

49, Dan Hughes. Wow, lots to think about there. Thanks!

52. Dereksaid

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.

53. steven moshersaid

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/

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:

54. steven moshersaid

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.

55. steven moshersaid

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.

56. steven moshersaid

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.

57. michelsaid

#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.

58. steven moshersaid

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.

59. JAEsaid

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.

60. RBsaid

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 :)

61. Nullius in Verbasaid

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.

62. Jeff Idsaid

#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.

63. Pat Franksaid

#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.

64. Iridiumsaid

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.

65. Jeff Idsaid

#63, I hope you understand that I don’t hold radiation theory to describe response, just that it exists and it works.

66. Iridiumsaid

“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 ;)

67. Jeff Idsaid

#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.

68. Carricksaid

Pat Frank:

I don’t understand how so many well trained people come to think that radiation physics is an adequate theory of climate response

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.

69. scienceofdoomsaid

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.

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.

70. scienceofdoomsaid

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).

71. JAEsaid

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.

72. Pat Franksaid

#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. :-)

73. DeWitt Paynesaid

If you deny RTE you are denying something YOU DON’T 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.

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.

74. Nullius in Verbasaid

#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!

75. DeWitt Paynesaid

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?

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.

76. steven moshersaid

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.

77. DeWitt Paynesaid

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.

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.

78. Geoff Sherringtonsaid

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.

79. Steve Fitzpatricksaid

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.

80. Cement a friendsaid

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

81. DeWitt Paynesaid

So high in the atmosphere a lot of re-emission takes place with much less conversion to sensible heat.

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.

267. manackersaid

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

268. DeWitt Paynesaid

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.

269. RBsaid

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 .

270. Steve Shortsaid

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!

271. Jan Pompesaid

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.

272. DeWitt Paynesaid

From the review on Amazon.com:

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.

Just because something appears in the peer-reviewed literature does not make it worth reading, much less spending $150 on it. 273. Steve Shortsaid 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 (;-)! 274. Steve Shortsaid 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!!! 275. Steve Shortsaid http://en.wikipedia.org/wiki/Wikipedia:Articles_for_deletion/Law_of_maximum_entropy_production 276. manackersaid 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 277. manackersaid DeWitt Payne Earlier you stated: 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. 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 278. DeWitt Paynesaid 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.

279. DeWitt Paynesaid

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.

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.

280. Nick Stokessaid

Re: DeWitt Payne (May 15 18:33),
Free version here.

281. DeWitt Paynesaid

Either they’ve taken it down or the link’s broken. I get a 404 error.

282. DeWitt Paynesaid

Went back to the original WUWT article and found a working link to the paper at http://www.leif.org

Thanks.

283. DeWitt Paynesaid

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.

284. Steve Shortsaid

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.

285. Steve Shortsaid

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…..

286. Steve Shortsaid

And this is always worth a read (or re-read):

http://climateaudit.org/2008/01/14/from-lacis-et-al-1981-to-archer-modtran/

287. DeWitt Paynesaid

Uh, Nature Geoscience is fully online…..

293. Dereksaid

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.)

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.

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,

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…

294. Ferenc M. Miskolczisaid

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.

295. Dereksaid

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.

296. Ferenc M. Miskolczisaid

#

Dear All,

I made a new attempt to clarify my opinion about AGW – and the Government Greenhouse Effect:

ae474618bfb4102&pi=8

I hope not everyone is jobless scientist like me, and you may afford the article.

297. Carricksaid

Corrected version of Ferenc’s link.

Or not…

Try this

299. Jeff Idsaid

#296 – would you mind emailing a copy of the paper? I don’t have university style access to these things.

300. Dereksaid

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.

301. Ferenc M. Miskolczisaid

#299

Jeff, send me an e-mail to fmiskolczi@cox.net .
I will send you a reprint.

Ferenc

302. kimsaid

Ah, theory and observations. Now we are getting somewhere.
===============

303. Ferenc M. Miskolczisaid

#

Dear All,

In case you read the

article, there is a typo in page 253. In the 6th line from the top there is a missing hat, ‘^’, from above tau_A.

304. Ferenc M. Miskolczisaid

# 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….

305. kimsaid

Heh, it’s a travesty that they can’t find the missing refutation.
==============

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308. Paulsaid

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

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310. olsonjs444said

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

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312. dboehlersaid

Reblogged this on emisciency and commented:
Good explanation of how CO2 warms up the atmosphere – more scientific than the “blanket” but still comprehensible.

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315. Mark Rubinsaid

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.

316. Mark Rubinsaid

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.

• Jeff Idsaid

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.

• Mark Rubinsaid

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.

• Jeff Idsaid

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.

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318. Triffidsaid

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 ?

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