Tom Vonk wrote an interesting post at WUWT in which he describes some of the quantum mechanics of IR absorption and makes the conclusion that radiative energy delay effects of CO2 are flatly false. Click the headline for Tom’s excellent article.
CO2 heats the atmosphere…a counter view
Guest post By Tom Vonk (Tom is a physicist and long time poster at many climate blogs. Note also I’ll have another essay coming soon supporting the role of CO2 – Anthony)
The simplistic view of CO2 heat trapping
If you search for “greenhouse effect” in Google and get 1 cent for statements like…
“CO2 absorbs the outgoing infrared energy and warms the atmosphere” – or – “CO2 traps part of the infrared radiation between ground and the upper part of the atmosphere”
…you will be millionaire .
Even Internet sites that are said to have a good scientific level like “Science of doom” publish statements similar to those quoted above . These statements are all wrong yet happen so often that I submitted this guest post to Anthony to clear this issue once for all.
Of course the Air Vent is one of those sites he claims is wrong, I left a comment explaining where he went wrong in his analysis, it seems to have vanished from the moderation queue it’s up now.
Tom really did do a good job, so I’m not disparaging his work, what it does do though is create a lot of confusion in the crowd which is something Tamino accuses every non-extremist warmer of doing. Here is an experiment he defined as proof that the energy in equals energy out so that CO2 simply cannot cause warming.
For those who prefer experimental proofs to theoretical arguments , here is a simple experiment demonstrating the above statements . Let us consider a hollow sphere at 15°C filled with air . You install an IR detector on the surface of the cavity . This is equivalent to the atmosphere during the night . The cavity will emit IR according to a black body law . Some frequencies of this BB radiation will be absorbed by the vibration modes of the CO2 molecules present in the air . What you will observe is :
- The detector shows that the cavity absorbs the same power on 15µ as it emits
- The temperature of the air stays at 15°C and more specifically the N2 and O2 do not heat
These observations demonstrate as expected that CO2 emits the same power as it absorbs and that there is no net energy transfer between the vibrational modes of CO2 and the translational modes of N2 and O2 . If you double the CO2 concentration or make the temperature vary , the observations stay identical showing that the conclusions we made are independent of temperatures and CO2 concentrations .
It’s a simple concept the gas in a sphere filled with CO2 has the same temperature as a sphere filled with N2. It’s also correct. However, it is moot with respect to AGW. The basis of his claims is essentially that energy in = energy out. Which it does, if you take the time to read his post though, he uses correct physics to come to an incorrect conclusion. Deciding that radiative effects of CO2 aren’t real and AGW cannot exist. My comment at WUWT, rewritten for clarity, is below.
If define an experiment this way:
A thin rectangular box having two very large sides A and B parallel and opposite to each other, the other 4 sides having negligible area. Side A is a 1000Watt 15um IR emitter, side B is a perfect IR absorber.
If we take N2 and fill the volume, the N2 will reach an equilibrium temperature based on the temperature of the box and whatever radiation is absorbed. Now if we instantly change the gas content to be 50/50 N2 and CO2 which has better absorption of the 15um IR wavelength, an IR detector at side B would detect an instantaneous drop in IR energy at the 15um wavelength. I’m sure we can agree on that.
Co2 is basically black stuff at 15um, so when it is first introduced, side B would receive less than the equilibrium 1000 watts.
What would then happen over time, is the gas inside the box would stabilize to an equilibrium temperature representing the temperature of the box and the radiation absorbed. As the system stabilized, an energy detector at the absorbing B side would eventually record the same 1000Watts of energy transfer from the A side as before.
However, the gas temperature will stabilize slightly higher than the N2 gas. An effect guaranteed and in fact proven by the initial drop in IR at your detector and the time delay until the system re-stabilizes.
None of this violates your equations or assumptions.
Good try though.
The immediate drop in IR at side B when the gas is first exchanged, proves energy is being added to the gas – which means heat.
I say both experiments are right, but Tom’s conclusions are wrong. So I wonder who can describe what the difference is between my experiment and Tom’s?
the Air Vent 
Jeff,
“who can describe what the difference is between my experiment and Tom’s”
Well, yours simulates heat transfer between two places, and his does not (eg heat transfer from the surface to the emitting level of the atmosphere). Which means his has nothing to do with the ‘greenhouse effect’, and yours does.
Or more briefly, his experiment doesn’t at all test what it is claimed to test.
Or even more briefly, his experiment is silly.
I followed the link here from WUWT hoping to learn something, but still baffled. Can anyone please explain in simple language, how much energy would be available in the 15 micron band if the surface temperature was say 15C. Also if the surface temperature changes the available energy in the 15 micron band would follow.
So can this be expressed as a percentage? I have read unexplained posts elsewhere that put this figure as between 4% and 8% of the total IR energy radiated from any surface at any temperature.
Thanks for the main post even if I don’t understand it yet. I’m working on it. <:-)
Take a cell with transparent ends and perfectly insulated walls. The length doesn’t really matter. Now put a blackbody source at temperature T at one end and a spectrophotometer at the other. At equilibrium, the spectrophotometer will see the same blackbody curve and total flux for T whether the cell is evacuated or filled with any gas or mixture of gases. SpectralCalc actually had a bug in their software for a while where this wasn’t true. If the cell contains an absorbing gas, you will see absorption dips and lower total flux at the detector if the temperature of the cell is maintained below T and emission peaks if the cell is maintained above T. We see a greenhouse effect in the atmosphere because the temperature of the gas (atmosphere) on average is less than the temperature of the source (surface). That means the temperature of the source has to be increased to get the same flux at the detector (space) that would be present if the atmosphere were perfectly transparent.
Re: DeWitt Payne (Aug 5 13:57),
If pressed, I’ll pony up the $25 for another month’s subscription at SpectralCalc and calculate and post the spectra.
#2,
To know the approximate “energy available” in the 15 micron band at 15C, you would need to get the black-body radiation curve for 15C (288K), and see what fraction lies in the 15 micron region. But the ’15 micron’ absorption band is itself a curve which has considerable width and a certain “shape”… it’s not like the ’15 micron’ band is a perfectly defined wavelength range with zero transmission… so the amount of energy absorbed is a messy calculation involving both the black body radiation curve and the shape of the absorption band. Sorry, it just can be made very simple. Unfortunately, it is even a bit more complicated than the above suggests, because the net “shape” of the absorption band is different at different altitudes; the higher up you go, the more narrow the apparent width of the band, and the less energy is absorbed. Again, sorry, there is no really simple way to calculate the number you want.
#1 That didn’t take long.
#6,
Nope.
But I sure don’t suggest you try to convince people at WUWT! You can spend an umlimited amount of time trying, and you won’t likely make much progress; been there, done that.
I was rather hoping Anthony would pick this post up. I don’t think that Tom’s analysis does much for WUWT, but it was a fun argument — Unfortunately, it confused most of the readers.
Jeff,
The key is the temperature of the gas in the box compared to the source temperature. Your experiment doesn’t define the box temperature or the source temperature or the detector for that matter. You can’t calculate the effective source temperature without knowing its bandwidth. You can’t calculate the box temperature at all. For a given bandwidth and temperature, an instantaneous addition of CO2 could decrease or increase the observed total (over all wavelengths) flux. A 1,000 W laser source with very narrow bandwidth is going to have a very high effective temperature so it’s virtually certain that the addition will decrease the flux of the laser line and the emission bandwidth will be much greater than the source bandwidth (you’ll likely get emission at the shorter wavelength CO2 bands as well as the 15 micrometer band) so the equilibrium temperature of the box with CO2 will be much less than the effective temperature of the source. If the detector is narrow bandwidth too, then the flux out in the presence of CO2 will never reach 1,000 W. In other words, your experiment is not really so simple as it first appears.
#8,
It sure does NOT do anything good for WUWT, nor the readers of the blog.
Anthony is a very good guy, but I think he should run posts like TomVonk’s past some trusted, technically trained friends. Sort of like an informal (dare I say it?) ‘peer review’. This would screen out crazy stuff… like last year’s post on how much CO2 solid might be forming in Antarctica…. but still let all the reasonable stuff through. If you, DeWitt, and I discussed this post with TomVonk, I am sure he would ultimately see what is wrong, but once it is posted, people tend to dig their heels in, and technically correct refutations are lost in the noise. Too bad.
#9,
Perfectly correct, as usual.. 🙂
I vote that you go over the WUWT and straighten this issue out! 🙂
#9 I solved the problem by 1000 watts of 15 um energy in and 1000 undefined watts out. I also used an energy detector (what ever that is) and a IR detector so I mixed my sensors to make it simpler. I do like your glass box (cell) idea though, it might be easier for people to understand.
I wish the AGW skeptic crowd was more uniform in accepting these simple facts. This says nothing about the magnitude of the warming, it says nothing about the dangers or feedback. All it shows is that CO2 does capture heat. People have to get this, before they can make a credible argument about the rest.
The reasonable argument lies elsewhere.
The reasonable argument lies elsewhere.
Ya think?
If basic physics’ thermodynamic Conservation Laws generally require that heat dissipates from open (planetary atmospheric) systems, while closed systems subside to thermal equilibrium via cooling by convective heat-exchange, it would seem that Lorenz’s Chaos Theory (1964) demonstrates that linear extrapolations of complex dynamic systems (those with three or more interacting variables) is mathematically impossible and, therefore, can not be computed/modeled.
As a former weather forecaster from the days at the dawning of satellites and mainframe computers, I’ve always been facinated about a busted wx forecast that occured in South Carolina during the 1970’s partial solar eclipse (~73%). Forecast for the day was for clear, blue skies and cool temperatures yet within minutes after the peak obscuration of the sun, a dense layer of altostratus formed at ~9,000′ AGL that persisted until well after sunset.
We busted both due to having >50% cloud cover below 10,000′ as well as missing the forecasted temperature being off by >10-F.
Likewise, being around in the days of cold war’s dooms-day warnings of a nuclear winter/ice age, I still find it hard to believe/accept the portent of a tripping point due to increases of CO2 leading to a run away AGW.
“linear extrapolations of complex dynamic systems (those with three or more interacting variables) is mathematically impossible and, therefore, can not be computed/modeled.”
Basic thermodynamic theory seem most concerned with, and therefore most experimented with the input/output aspects of systems, whether open or closed. The assumptions and simplifications made with that mindset are hopeless in the context of varying compositions versus ultimate effect, especially in a system that has NO equilibrium state. It’s like finding a string of eight eights in the 20,000th decimal point of pi and drawing the conclusion there are nine nines at the 40,000th decimal point.
Climate science will never mature until it accepts the inherent limitations in their methodology. In modeling, first and foremost. If the alarmists would cease their confirmation biased modeling long enough to develop the tools they need to do the job, they might have my respect. Frankly, as great an admirer of Lorenz as I am, I think Chaos Theory is an excuse used by lazy scientists to avoid a difficult task. This might seem contradictory to what I stated above, but I think there is a distinct difference between a chaotic system and a complex system.
#15,
I think you are just missing Jeff’s point.
Sure, catastrophic AGW and all that goes into it (especially GCM’s) may very well be nothing but hogwash. That does not mean that adding an infrared absorbing gas to the atmosphere can’t be expected to cause SOME (size not known) warming. The issue is one of basic credibility. When someone says increasing CO2 can’t possibly have any effect on surface temperature, then nobody who knows something about radiative physics is going to believe anything else they say. Not accepting long settled (late 1800’s) basic science simply destroys your credibility. Jeff wants people to differentiate between what science really is ‘settled’ and what is not.
How about an explanation that dumbs down everything bit while taking no terms or ideas as known to those you are talking to. If there is one thing that I see in many debates is that some people misunderstand what others are saying. Basically people use college level arguments over misunderstandings of an elementary school level definition/concept.
Like the “CO2 traps heat”. Isn’t the biggest problem with that simply the fact that “trap” has not been defined in this instance. Some people take it as meaning captured forever. So a big elaborate post is made to debunk the notion that the energy is not actually in a mechanism that forever captures the energy (15µ comes in and 15µ goes out, see heat is not trapped). What if “trap” simply means something that makes escape more difficult?
Just for fun I decided to look up a VERY simple explanation for energy transfer. In Google seach I put in “transfer of energy for kids”. Looking at the definitions given (from the first link here: http://www.kids.esdb.bg/basic_principles.html) it is easy to see that many commenters (and sometimes article posters themselves) are misunderstanding terms and concepts that kids are supposed to be able to grasp.
Yes I thought it was rather interesting and plausible.
It contradicted my “world view” of the atmosphere.
I thought much more thermalisation was possible.
However taken point at a time could we all arrive at a settled view on some of his conjectures.
For some time Ive been wondering how to reconcile the photoelectric effect rejection of larger wavelengths and Earth surface rejection of “backradiation might be linked through quantum mechanical constraints.
TPaul/#16 —
“…Climate science will never mature until it accepts the inherent limitations in their methodology. In modeling, first and foremost. If the alarmists would cease their confirmation biased modeling long enough to develop the tools they need to do the job, they might have my respect. Frankly, as great an admirer of Lorenz as I am, I think Chaos Theory is an excuse used by lazy scientists to avoid a difficult task. This might seem contradictory to what I stated above, but I think there is a distinct difference between a chaotic system and a complex system.”
>>Actually, TPaul’s statement is closer to my intended point — Having been professionally employed to attempt to apply science in generating my best guess (SWAG?) as to what selected weather parameters in the near future over micro/macro extents would be, I became acutely aware of just how ignorant we are of the influencing variables. Some classmates of mine went on to develop the original upper air computer models utilized for extended wx forecasts that greatly improved our understanding and forecast accuracy.
But, can any distinct differences between a chaotic system and a complex system be truely understood/identified in a dynamic system? I submit that our planetary weather/climate is both chaotic and complex – [How was I to know that a farmer starting overhead irrigation of a large alfalfa field would generate sufficient water vapor locally to initiate an unforecasted thunderstorm/tornado in the afternoon?]
Bottom line, we’re still learning that we haven’t identified, much less fully understand or even started to measure, the complex/chaotic variables and/or their interactions/feedbacks. Much as Lorenz found out about significant digits being dropped can impact an outcome, we haven’t even realized what significant variables, or their interactions, that are/might be at play. To blindly accept current computer models as gospel and impose political mandates based on them, IMHO, is pretty audacious and dangerous.
Steve/#17 —
“Not accepting long settled (late 1800′s) basic science simply destroys your credibility.”
I believe my comment was: “…I still find it hard to believe/accept the portent of a tripping point due to increases of CO2 leading to a run away AGW.” The science is pretty well established about CO2/GHG potentials in selected circumstances/system constraints — not so well established or understood, IMHO, in our planet’s atmospheric circumstances.
My posted point on the topic/subject was more of an attempt to differentiate that Jeff’s astute comment #14 – “The reasonable argument lies elsewhere.” was perhaps the better statement that we need to appreciate more fully.
#18, Right. Most people need the caveman level explanation (note to non-US readers: this refers to a tv advertisement for insurance that claims buying their product is “so easy a caveman can do it.”) because college (or high school) physics was too long ago or never taken at all.
Jeff: I may be in over my head again, but it seems to me that you don’t accept/understand? LTE.
21, Watch out with that Caveman stuff. We have lots of ’em in Southern Oregon!
Jeff says:
“I wish the AGW skeptic crowd was more uniform in accepting these simple facts. This says nothing about the magnitude of the warming, it says nothing about the dangers or feedback. All it shows is that CO2 does capture heat. People have to get this, before they can make a credible argument about the rest.”
Sorry, but as you probably know by now, I must be colored “a skeptical idiot” by your standards. But I think you are maybe the wrong one. Unless there is some empirical proof of the GHE, it simply does not exist, SCIENTIFICALLY! Poor Roy Spencer is trying to deal with this problem on his blog, with no success that I can discern. Your idea of “simple facts” could very well the thought patterns of the Inquisitioners. Think about this and deal with this as you must!
#24, Roy and I agree on this and have no difference of opinion on radiative capture to my knowledge.
I haven’t been there today but have enjoyed his recent posts in the past week and the discussion on the matter. It is a simple issue, but I haven’t struck the chord with the audience yet.
Please don’t misconstrue my understanding of radiative physics for agreement with extremist AGW. It’s a different topic IMO.
“It is a simple issue, but I haven’t struck the chord with the audience yet.
Please don’t misconstrue my understanding of radiative physics for agreement with extremist AGW. It’s a different topic IMO.”
Well, with all due respect, I beg to differ on the “simple issue” issue. It is very far from simple, or we would not have brilliant people like Tom Vonk, Ferenc Miskolski, Allan Siddons, etc. arguing about it. The bottom line is still empirical evidence. Even Einstein had to wait for years for the “right” solar eclipse to prove that light was bent by gravity. Without that empirical evidence, Einstein might still be a “crackpot.”
Model experiments can be good for education, but they can be problematic if both static and dynamic effects are happening. Fellow chemist DeWitt at 3 notes this with his caveat about temperatures. What is left unstated is the case of allowing time for the systems to reach equilibrium. How long does it take, what are the end states, where does the energy finally report?
On a related topic, it is self evident that gases can be overall producers of heat. That’s what LASER stands for. Light amplification through stimulated emission of radiation. That’s easy to say, but it’s far more complex to relate it to what happens in the atmosphere. I’d be reluctant to go back to my spectroscopy days and make assertions, without a number of months of rehearsal. I still know enough to suspect some possible errors here and there, but really, it’s a full-time subject for specialists. Spectroscopy is a topic that starts off simply with topics like the Beer-Lambert relation and rapidly gets very complex as you get into quantised transitions and beyond.
As I have said at least 100 times, the “bottom line” is that Atlanta is much cooler than Phoenix in summer (both night and day), despite 2-3 times more GHGs in Atlanta (these locations are at virtually the same elevation and latitude). I don’t care whether this is due to more HOH in Atlanta (latent heat effect), more clouds in Atlanta (less solar radiation), more people in Atlanta… it is shown clearly in the actual empirical data, which cannot be denied and should be explained, rather than ignored, by the “warmers.” This is important, because it shows that the HOH COOLING effect in Atlanta (see
Eschenbach’s stuff) is much more powerful than some mysterious OCO “greenhouse” effect, which might be operable in a small part of the atmosphere. The whole CO2 GHG idea is an overrated, unproven, undemnostrable, unscientific bunch of supposition. Only empirical evidence of the “atmospheric greenhouse effect” will resolve this basic connundrum. Politics can’t do it.
“Well, with all due respect, I beg to differ on the “simple issue” issue. It is very far from simple, or we would not have brilliant people like Tom Vonk, Ferenc Miskolski, Allan Siddons, etc. arguing about it”
I once argued with a professor about Coriolis acceleration for an entire semester. I was marked wrong on the test, 80 percent of the class got his answer. I hadn’t been to class because I learned it from the books. I brought him dozens of examples, proofs and other items, talked to multiple other professors who refused to help.
It wasn’t until the final exam that he admitted his error, by that time I had stopped going to class and I failed. Everyone who got my answer 2 of 50 got credit, everyone who got his answer still got credit. Coriolis acceleration is as well understood as CO2 heat capture.
There simply is no room for disagreement on this because the physics are simple, known and sound and when smart skeptics say there is, it automatically relegates them to second class science.
Except Tom just explained why CO2 would transfer 0 energy to the other particles in the mix. If they are all at the same temp when they impact there is 0 transfer. This is NOT a radiative question.
Did you miss the part where he explained the energy absorbed in the molecular bonds was not available for transfer in collision mode with a particle at the same temp?? Would you please explain where he got it wrong??
In a real atmosphere for there to be warming the CO2 molecule would have to be WARMER than the rest for conduction (collision). Does increasing the bond temp equate to kinetic heat?? Tom claims it does not in a meaningful way. That should be where the argument lies.
The question of whether IR from a colder molecule can warm, or slow the cooling of, a warmer molecule was not addressed at all.
By the way Jeff, when was the physics described in the following page proven false??
http://www.olympusmicro.com/primer/lightandcolor/interference.html
Nothing wrong with the physics, only with your understanding of it. What did you miss the last time around?
I cannot judge your being right or wrong on this but will offer this observation. You do sometimes sound like Gavin.
#30 No, what tom explained was that energy captured in CO2 would transfer to N2 and back to CO2 in equal amounts under his scenario’s. What he did not demonstrate is what happens when radiative heat is added to the mix. That confusion he’s added will do nothing but cause problems because when you present that to people who know what is going on, nobody will listen after that.
I’ve got no idea why you gave me a link to light interference. In college I worked in a holography lab for about 5 years studying engines, airfoils and that sort of thing. It’s how I ended up working the rest of my life in optics.
#32, Ouch!! That might be the worst insult I’ve received in blogland. I’m working on a better demonstration for you. Maybe you’ll like that one.
————
Perhaps you guys should tell me where my experiment is wrong rather than just bash at it. It’s very simple physics. It makes me giggle to think that some guy has convinced you people that a thousand watts of IR light on a small volume of gas won’t create heat.
I think the base issue is that the physics of thermodynamics can only really address equilibrium conditions. As such do not exist in the atmosphere, it makes no sense to appeal to the basic principals of physics to support a claim that CO2 warms the atmosphere. Such claims can only be substantiated empirically (by observation).
Jeff, your thought experiment is only that, a thought experiment. There is no analytical mathematic solution to such a system that would prove your point. It might make sense intuitively, but the only way to prove it is to run the experiment.
#33,
It is almost painful to watch your back-and-forth on this thread about a subject that is so well understood. Many comments are of comparable quality to the non-sense spouted by the CAGW crowd. Just sad, really sad.
I once had a high school “science” teacher who carefully explained to the entire class how physical wear (loss of mass) of automobile break pads was an example of conversion of matter to energy (yes, E = MC^2), with the missing mass of the pads converted to “negative energy”, which “absorbed” the car’s “positive” kinetic energy. I must have looked pretty funny that day in class with my mouth hanging open. When classes were over for the day, I returned to his room and tried to explain all the conceptual errors involved in that absurd explanation, but when he would not budge on any of it, I knew any further effort would be a waste of time. From then on, I just ignored everything he said. Since you are facing a very similar situation here, I suggest you consider a similar tactic.
A while ago, since it’s way outside my area of expertise in physics, I spent a bit of time studying this by looking into Chandrasekar’s book “Radiative Transfer” and a few journal articles. My understanding is that adding CO2 or any other IR absorbing gas (1) changes the rate of heat loss from the surface and (2) causes a temperature discontinuity between the surface and the gas above it. What I found most interesting is that the temperature profile of the atmosphere (lapse rate) is inserted as a given into the equation of transfer and doesn’t change regardless of the concentration of the IR absorbing gas. The surface discontinuity is going to be removed very quickly by convection at the surface boundary layer.
Vonk’s article is an interesting discussion of the microphysics of equilibrium but a diversion and not to the point of how an IR gas affects the atmosphere.
People might be interested to check out some of the recent stuff on Roy Spencers website (http://www.drroyspencer.com/) which covers some of these issues, together with experiments!
I gave up trying to understand CO2 after battling Ferdinand Engelbeen. I realized it was not essential for me to grasp, in order to be able to thoroughly refute CAGW. Now I tend to trust my hunches. Hunch 1: neither FE nor Tom Vonk are right. Tom’s stuff simply feels wrong, it has no “engineering” feel to it, and no testability with data. FE’s stuff completely omits the overarching size of the natural CO2 cycle and treats this living entity like it follows rules as rigidly as a tape ruler. Hunch 2: enter Jeff Id at WUWT, I suspect his stuff is better than either. And most of the scientifically sharp, aware folk here think so too, some even understand (?) it. Hunch 3: I suspect that Miskolczi is on the mark too: his theory fits the data with incredible precision. But he’s Hungarian and incomprehensible. Hunch 4: Gerlich & Tscheuschner are out of the same stable as Tom Vonk.
Now the “evidence” for these hunches is airy-fairy to say the least. But my experience shows me that when I’ve trusted hunches like these and really gone digging for evidence, that too has come. Like it did for me for Yamal (none of the local thermometer records even remotely touch the extreme range the treering data supposedly gave – ergo, treering calibration is suspect).
You don’t need explanations at all. But any theories you propose, MUST fit the data legal-style – the data, the whole data, and nothing but the data.
Yippee! Just as I write this, Jeff appears at WUWT. Congrats!
As most probably know, ScienceOfDoom http://scienceofdoom.com/2010/07/26/do-trenberth-and-kiehl-understand-the-first-law-of-thermodynamics/ has a similar discussion. SoD’s is quite similar to Jeff’s except that he replaces the gas with PVC and stipulates that the PVC heats up by conduction.
Jeff, you’re right of course on the greenhouse effect but I did not read toms conclusions as you have. Granted I didn’t read closely, but I think his claim was that the cartoon of the greenhouse effect–he has a quote early on–uses the wrong words and images. He then goes on to explai why this is so–and he is justified with regards to the fine grain even its not relevant to the big picture.
The he claims that if the speaker isn’t right about the little word choices, he cannot be trusted to understand the big idea: the manifestation of the greenhouse effect.
That is a falacious claim…
To his credit to makes it quite clear that his quibble with wording does not hit upon the big picture issues.
Granted that co2 absorbs infrared radiation.
Granted that co2 adds slightly to the heat capacity of the atmosphere.
Calling it insulation is backwards because of that.
If real life, it exists as part of a fluid system that is constantly cycled by convection.
That means the function it performs is a carrier of heat- the function you ascribe to it, but the context of which you drop (and as a result get an inverted notion).
That means, in a convective flow, it IMPROVES the cooling of the source by moving heat more efficiently to the sink.
(and the source can not be the sink too)
Here’s your simple experiment:
Add carbon black to the fluid in your radiator.
Your engine will run cooler, guaranteed.
It won’t be ‘insulated’.
Belated thanks to Steve Fitzpatrick, Post #5, for taking the time to respond. Lacking any formal training I also work on hunches, Post #38. It seems optical density of the 15 micron band will have most effect on “feedback”. I also feel the “down path” will show similar response to the “up path” but because of lower density/temperature issues will have a much longer path length. Either way it gives a constant for feedback over the 15 micron band which supports the claim that doubling CO2 will not change the feedback levels, just shorten the path length.
Gnomish said at 41: Granted that co2 adds slightly to the heat capacity of the atmosphere.
Paul Linsay observed at 36: …looking into Chandrasekar’s book “Radiative Transfer”…. What I found most interesting is that the temperature profile of the atmosphere (lapse rate) is inserted as a given into the equation of transfer and DOESN’T CHANGE REGARDLESS OF THE CONCENTRATION OF THE IR ABSORBING GAS.
The lapse rate is given by -g/c, g = accel. due to gravity, c = specific heat of the gas (=c_sub v for dry adiabatic conditions, for example). It doesn’t matter whether the HEAT CAPACITY is changed, what matters is that the addition of a few hundred ppm of co2 cannot change the SPECIFIC HEAT of the atmosphere, which governs the lapse rate and thus the temperature you measure at a fixed station. The governing fact is that the IR radiation absorbed and emitted by the co2 is just heat energy, and heat energy will take the fastest way to come to the same final equilibrium (whether by conduction, convection, radiation, or a real-world combination), so adding co2 just gives the system more of a radiative component, which it will take at any point where that is the fastest way. Adding co2 can only increase the efficiency of heat transfer in the atmosphere.
Jeff Id’s thought experiment thus has two errors: He adds an unrealistic amount of co2, but more importantly, he jumps without logical justification from “an initial drop in IR at the detector, and thus a time delay (how long? a microscopic instant longer than with N2, at most) before stabilization”, to “the system will stabilize at a slightly higher temperature.” For shame.
Physicists like Tom Vonk, and Gerlich and Tschueschner, are correct: The “greenhouse effect” is incompetent garbage (and also a fraud, since the models that use it have been shown to have failed, in numerous ways, and natural components to the climate system like the oceanic multidecadal oscillation, driven by changes in the Sun’s activity, have been shown to fit the global temperature data well since the end of the Little Ice Age, while the climate models do not, most damningly in the last 10 years). A hundred plus years of “greenhouse” incompetence is still just incompetence. The first time you heard of the thermodynamic determination of the lapse rate, independent of IR absorption in the atmosphere, you should have seen this.
#43,
Vonk actually agreed with me on this post as I understand it. You are mixing the magnitude with the existence of the effect.
In an op-amp you can wire a simple amplifier with negative feedback such that when you increase the input the output changes nearly zero. You can also wire it to have a net gain over the normal input. This is where the CO2 argument lies, not in whether CO2 captures heat but rather, how much heat, is it measurable, is it a problem and finally what can we do about it if anything.
I’ve seen no convincing evidence that we can do anything first, no evidence that it is a problem, weak evidence that its effects can be measured and strong evidence that CO2 captures IR.
There is a point I don’t understand here.
If we have a photon of IR intercepted by a greenhouse molecule, the energy (temperature) of the molecule is increased. The photon will be reemitted, thus “cooling” the molecule again, under normal circumstances in an unimaginably short time. If it goes “down”, it will simply be returning to some (possibly surface) molecule which was cooled by emitting it in the first place.
So we have neither a change in total mass nor a change in total molecular energy. So absent an external energy source, how can we get a change in temperature? And if we do have an external energy source, what sense does it make to attribute any of the change in surface temperature to the greenhouse molecule rather than to the energy source? If CO2 “captures” IR, it must be more like a catch-and-release fishing tournament…
(Observe, by the way, that at the same moment your IR detector showed a momentary drop in wattage, it also cooled…)
Another point is that Tom Vonk’s post demonstrated (as he said) only that CO2 can’t heat N2, not that IR can’t heat CO2 (which of course it can). Temperature is a measure of average molecular energy; if 50% of the molecules are warmer and 50% are unaffected, you’ll measure warmer. If 0.04% of the molecules are warmer and 97% are unaffected, you’ll probably have trouble measuring anything.
Nahle’s paper at http://www.biocab.org/Mean_Free_Path.pdf is interesting. Turns out the CO2 delay for a photon is about 4 milliseconds surface to stratosphere…
Re: Craig Goodrich (Dec 2 13:42),
Unless you think that the microsecond range is an unimaginably short time, you’re wrong. In fact the probability of an excited molecule emitting a photon before it transfers the energy to another molecule (and it doesn’t have to be a CO2 molecule) by inelastic collision is on the order of 0.0001. Spontaneous emission is actually a relatively slow process. See my article here.
While it’s a long time since you originally posted, I have been trying to figure out the truth of the CO2 IR absorption/emission problem. Tom Vonk’s analysis makes complete sense. I note there is no experimental evidence of thermalisation of CO2 by IR, excepting for radiative transfer data collected within IR-reflective chambers. A body of CO2 will absorb and nearly instantaneously re-emit IR, resulting in scattering in random directions. This is what Tyndall observed but he did not measure the scattering, nor did he measure thermalisation. Why there is is no experiment to demonstrate the truth of this is a mystery to me. Maybe because it is too obvious to real physicists and too confronting for climate scientists.
OTOH, a simple word experiment proves that IR absorbing/emitting gases must cool the atmosphere and nothing but the sun will make a difference in the long-term.
An earth which is unable to emit IR from the surface would be isothermal. Earth has no significant mass transfer with space. An isothermal earth must be much warmer at the surface than presently, because of the internal heat source which is the core. Even if there is no sun, an earth unable to emit will be warmer at the surface. If there is no sun and we add IR emitters at the surface/atmosphere, the earth will be cooler than the isothermal non-IR emitting earth. Ergo, it is the role of IR absorber/emitters to cool the surface to less than isothermal by radiation to space.
Cyclic heating/cooling of the surface by the sun adds a small amount of heat energy, but this amount is entirely dependent on cyclic heating cooling effects and the magnitude of sun’s radiation. Solar effects on climate are well described. I believe the cyclic heating/cooling effects are on average will be independent of all known physical parameters – molecular composition, IR absorption, etc. Anything which might heat faster in the daytime sun will cool faster in the night. Anything which might absorb more in the day will emit more at night. Anything which can heat or cool asymmetrically in the heating/cooling cycle without the addition of work must represent a perpetuum mobile.
Experiments in a physics lab can easily demonstrate the truth.