CO2 heats the atmosphere…a counter view

Oopsie!
There goes “Cap’N’Trade”…

— > swish it goes over the head

The conclusions is ….(?) that the green house effect works as scientists have known for over a century, but some of the simplified terminology often found in textbooks is misleading (?)

“The simplistic view of CO2 heat trapping”
—
And by “simplistic”, you mean “wrong”, right?
What is trying to be demonstrated by the graphic is the long-wave radiation absorptivity of the atmosphere. What it is showing is that the atmosphere “reflects” such radiation back toward the ground, which is just bad science.
Would it have been so difficult to terminate the smaller atmospheric absorption arrow in the atmosphere itself and then have a separate set of arrows (both toward the surface and into space) showing the radiative energy from the atmosphere?
It still would have been “simplistic”, but also “correct”.

Tom,
Thanks for your essay. I think I understand “most” of what you were saying. Could you please comment on the ideas presented in this video and explain where they violate the physics.
http://earthguide.ucsd.edu/earthguide/diagrams/greenhouse/
Thanks, I would appreciate it.

It’s great to see someone clearing the air about the basic physics of the system. Too often we see sweeping, simple-to-understand analogies that are simply wrong.
like:
“CO2 traps heat in the atmosphere like a blanket”
“Infrared energy (which is heat)…”
Stuff like that is like fingernails on a blackboard to me, and I’m not even a physicist. I just paid attention during my freshman year.
Ed

If the above is true then how do NDIR CO2 measuring instruments work. They detect CO2 either by the attenuation of an IR beam passing through the cell with the test gas or by detecting the temperature rise of the gas in the cell. Both of these would require absorption of IR by the CO2 and that energy has to go somewhere.

I would like to add:
The theory of AGW says that extra CO2 causes a minor warming (less than 0.5degree) which then causes the atmosphere to absorb more water vapour. H2O content of the atmosphere is dependant on temperature – if you warm the air by 0.5C it can hold a little more H2O. This small increase in H2O then increases atmospheric temperature since H20 is a strong GHG which then allows more H2O to be absorbed etc (positive feedback loop).
The problem that the AGW’ers ignore is that when that first stage of extra H2O absorption happens, the H2O comes from evaporation from the oceans/surface water. Evaporation is a Endothermic process which causes a COOLING effect, so the first stage of H2O absorption MUST causes a slight cooling of the oceans which will offset the slight warming of the initial CO2. They have ignored this.
Not only that, but the slight cooling of the oceans from step1, results in the oceans being able to absorb more CO2, since CO2 absorption in the oceans is dependant on ocean temperature (when temperatures go up, oceans release CO2, when temps go down, oceans absorb CO2). So the slight cooling from the evaporated H2O will actually cause the oceans to absorb some of the CO2 back.
ie. Nature ballances itself out.

Help me here… A system in equilibrium quickly returns to equilibrium at a higher level when it absorbs an IR photon: CO2+N2CO2+N2 becomes CO2*+N2CO2+N2+ (pardon the limited special character skills). This looks like heating to me, and, the temperature is controlled by the variance in the rate of absorbed and emitted IR photons for any small volume.
What I really don’t understand is why water and CO2 are better, by a factor of 20, at this as N2 and O2

Many, many thanks for this.
I am going to be busy for a while. < 🙂

My above entry would have looked better if the system had not erased my left and right carrots from the equations.
[Note: “Caret.” And the angle brackets can be created so they will not disappear with the HTML command: &, lt [or gt], ; (Delete the commas & spaces but keep the semicolon.) Put together, the “lt” command will create a ‘less than’ angle bracket; “gt” will create a ‘greater than’ bracket: < > ~dbs]

Interesting article Tom. However, there is one point I did not quite understand.
In equation (2) you wrote CO2* + N2 → CO2 + N2⁺ (2)
This reads “a vibrationally excited CO2 molecule CO2* collides with an N2 molecule and relaxes to a lower vibrational energy state CO2 while the N2 molecule increases its velocity to N2⁺ “.
But later you wrote: “As we have seen above that this relaxation cannot happen through collisions with N2 because no net energy transfer is permitted , only the process (1) is available .”
But doesn’t equation (2) say that CO2* collides with an N2 molecule and relaxes?

In other words CO2 which absorbs strongly the 15µ IR , will emit strongly almost exactly as much 15 µ radiation as it absorbs .
Why isn’t it “exactly”?

OT but {snip]
[reply] But me no buts, butter me no parsnips, off to Tips and Notes with you. 😉 RT-mod

I know that this is the first part of a series but having covered the action inside little boxes or spheres where delta size goes to a molecular level, what happens as the density changes?

Since there is no tropospheric warming that was predicted to happen in global warming seeing this explanation partly helps to clear up why.
Next I know there will be the argument of downward flux to the surface of energy from added co2 causes warming. But that isn’t happening either. That argument poorly incorporates the effects of H2O. There is found to be cooling at the surface when H2O is effected by that downward flux.
The global warming hypothesis is wrong.

Nice presentation, but an incorrect conclusion.

Thanks Tom. It might not have been as elegant as your own post, but basically I think we were saying the same thing – and it is great to have my model validated at last!
Submission to science and technology committee of UK parliament
Noddy Science: CO2 Warms the Planet?
(24) The complex bond structure within CO2 means that it can readily absorb and emit radiation in the infra-red (IR) band where thermal radiation is given off by a blackbody9 at the temperature of the earth. Much of this IR is at wavelengths at which other atmospheric constituents do not interact, so if CO2 is exposed to a warmer surface like the earth, it will absorb radiation that would otherwise pass through into the cold of space AND likewise if CO2 is exposed to the cool of outer space it will emit vast quantities of IR at wavelengths which other gases cannot emit.
(25) When CO2 is present low in the atmosphere, it tends to block transmission of these wavelengths into space and reduce heat loss to space. When CO2 is present high in the atmosphere, it helps emit IR, so causing cooling of the atmosphere acting as a vector by which other gases can lose heat into space. Like triple glazing, the system is complicated by the movement of air. Air warmed at the surface naturally tends to rise above the majority of the (blocking) atmosphere and it cannot descend until it has cooled by the emission of IR into the cool of outer space. CO2 cooling is as natural as CO2 warming, the atmosphere being a highly dynamic and complex system: a natural cooling system taking heat from the surface of the earth up into space via convective currents.
(26) Simple physics could suggest CO2 is a cooling gas as easily as warming and “obvious” assertions must be validated against real evidence, not the preconceptions of “scientists”. CO2 could impact the atmosphere in other ways: changes in specific heat capacity, density, interaction with water droplets and cloud formation. Other gases like water vapour also have their effects. It would be wrong to say that increases in CO2 can not affect the climate, but it is equally absurd, in such a complex system, to say this or that effect must dominate in the absence of the normal rigorous testing required by science.
http://www.publications.parliament.uk/pa/cm200910/cmselect/cmsctech/387b/387we32.htm

A fine starting off point in this post, especially with all the “yes, but … ” comments. Will have to come back to this later today to see what else has sprouted.

It’s been a few years since i studied physical chemistry. But something here doesn’t seem to add up.
“The LTE conditions with the energy equipartition law give immediately the answer : “These rates are exactly equal .” This means that for every collision where a vibrationally excited CO2* transfers energy to N2 , there is a collision where N2⁺ transfers the same energy to CO2 and excites it vibrationally . There is no net energy transfer from CO2 to N2 through the vibration-translation interaction .”
I believe this would only hold true if there was no net production or loss of either type of the two molecules CO2* and N2(+). This asumes there are no collisions like:
N2(+) + N2 = N2(0.5+) + N2 (0.5+)
Or similar collision of N2(+) with a non-exited CO2 molecule. A collision where the kinetic energy is split between two (or more) molecules, leading to a decay in number of molecules at N2(+) or near N2(+) kinetic energy levels. Which will eventually lead to the molecules reaching a Maxwell-Boltzmann kinetic enegy distribution.
Is there no such decay in kinetic energy levels for a system containing only CO2 and N2?
If there is such a decay then additional CO2* can be formed by IR absorption and feed the N2(+) which in turn decays into several N2(Y+) and CO2/y+) (where Y<1) and the distribution of these N2(y+) and CO2(Y+) defines the temperature.

Jeez guys, for those that are taking Tom to task about what he didn’t show, did you expect an entire advanced chem semester in one article? The way I took this lesson, is to bring people up to speed about how CO2 acts when excited by infrared heat. And then touched on the interaction between CO2 and N2. I don’t believe this was supposed to be an all encompassing comprehensive article explaining the entire radiative chemical processes of our atmosphere. Obviously, there’s more going on up there than this.
Tom, once again, thanks for putting this in terms easily expressed. I’d often thought the energy emissions of CO2 were equally outward as they were back to earth, but as I’ve alluded to earlier, chemistry never really held much of an interest to me during my college years.

Great presentation! Back to text book basics. I understand it because 60 years ago I used the rigid-rotator, harmonic-oscillater approximation to calculate classical thermodynamic functions, as a function of temperature. I doubt there are many post modern “climatetoligist” who have done that. My statistical analysis tends to confirm your conclusions. http://www.kidswincom.net/CO2OLR.pdf.

I would suggest the author edit some of the sentence structures and grammar before posting on such a hot topic. It detracts from his attempt to state his case. Further, I am not at all convinced that the treatise presented here is a strong case against increased CO2 (from any source) adding to the heating of the Earth’s atmosphere.
As a skeptic, my central issue is that I am not convinced that our noisy planet, with its intrinsic short and long term temperature variability from natural sources, can be adequately measured in such a way to detect anthropogenic CO2’s warming affect.

We’ve all seen the “proof” starting with a=1 and b=2, going through a series of seemingly valid algebraic manipulations, and ending with the conclusion that a=b. The trick, of course, is to hide a divide-by-zero operation somewhere in the proof.
Ton Vonk has made some similar errors.
First, throughout the article, he uses “temperature” when he is actually talking about “heat”. Except that sometimes, “temperature” really does mean temperature, so he can come to some seemingly valid conclusions that are completely wrong. I suspect that untangling “heat” and “temperature” throughout this essay would clearly show some of the places where he has gone off the rails.
Second, he treats the “energy equipartition law” as if it were an iron-clad law of physics that holds exactly at all scales of size and time. This is simply not true.
The equipartition law, like all such empirical laws, is a statistical approximation that becomes less and less accurate as the population of gas molecules becomes smaller. Yet this article treats it as if it must be obeyed exactly by any random pair of molecules. Also, this law can be temporarily violated by transient responses.
Let’s put one molecule of CO2 in a chamber with 78 molecules of N2 and 21 of O2 (to pull some random numbers out of thin air). Hit that lone CO2 with a 15 micro-meter photon of infrared light and let it absorb the photon. Instantly, the equipartition law is violated, because the CO2 molecule has gained more vibrational energy, which increases the total vibrational energy of the gas sample relative to the rotational and translational energy. Before long, the excessively vibrating CO2 molecule will bump into another molecule. Depending on the exact geometry of the collision, both could use that excess vibration to rebound with excess translational or rotational energy, or some combination. Both molecules then go on to collide with other molecules, and the energy increase eventually distributes throughout the volume, re-establishing local equilibrium, and re-establishing the energy partition. In the end, there is an infinitesimally higher heat energy content of our gas sample, and consequently an infinitesimally higher temperature.
So, yes, CO2 absorbing infrared light does indeed increase the temperature of the atmosphere.
The question that is usually un-asked, let alone satisfactorily answered, is “how much?”

To make my position clear: I come at this after many years of seeing creationists mis-use basic physics such as entropy and the laws of thermodynamics to “prove” that evolution can’t happen. And just as many years of arguing against those mis-uses. I don’t know much about climatology, but I know a LOT about how to spot bad arguments.
The opening paragraphs of this article give me the same tingling-down-the-back-of the-neck feeling as those creationist arguments about thermodynamics. It doesn’t feel right. The slightly patronizing writing style, the drastic simplifying of a very complex subject, the theme of ‘armchair genius uses basic facts to prove a major field of science wrong’ — all just like any pseudo-scientific creationist tract.
I have been a skeptic on AGW for several years and will likely remain so for years yet to come. But this article strikes me as bad science. Bad science on one side is no more justified than bad science on the other.

“These rates are exactly equal .” This means that for every collision where a vibrationally excited CO2* transfers energy to N2 , there is a collision where N2⁺ transfers the same energy to CO2 and excites it vibrationally . There is no net energy transfer from CO2 to N2 through the vibration-translation interaction .
Of course there is a net energy transfer from CO2 to N2, as in every equilibrium reaction: if you add something at one side of the equation, that pushes the reaction to the other side. In this case, you add energy to a CO2 molecule as it captures an IR foton. That increases the total energy content of the (micro)system: energy can’t be destroyed (except for energy-mass transfers, which isn’t the case here)… The increased energy content either is re-emitted by the CO2 molecule or redistributed over all the existant molecules by collisions. In the first case, half of it is directed to the surface. In the second case, the temperature of the mass increases. In the atmosphere, the warmer gas lifts up, causing an increase of the surface temperature due to the lapse rate.
Therefore in order to maintain the number of vibrationally excited molecules constant , every time a CO2 molecule absorbs an infrared photon and excites vibrationally , it is necessary that another CO2 molecule relaxes by going to a lower energy state .
That is true if there is no net radiation energy coming in as in your example. But (as Tyndal proved over 100 years ago): put a beam of IR, including the right frequency, through a volume of pure N2 and nothing happens. Put some CO2 in the same volume, and part of the IR is absorbed, increasing the temperature of the volume of gas. This proves beyond doubt that your reasoning doesn’t hold for a dynamic process where one of the components changes (either the amount of IR or the amount of CO2…).

So, a system at Local Thermodynamic Equilibrium doesn’t change temperature. Isn’t that the definition of Local Thermodynamic Equilibrium? I’m not sure I learned anything here.

This is an amazing exercise in disinformation: how to thoroughly muddle the waters while pretending to clarify.
All the greenhouse physics is hidden in caveat 1 and the weasel-y reference to “much more complex and not well understood aspects.”
Here’s a better “thought experiment” for you. Shine light on a black rubber sphere, uniformly, from all sides, until it gets hot. How hot? If the incoming energy flux is Iin, then it will get hot enough to radiate out at a rate Iup = Iin, in equilibrium.
Suppose that most of the radiation that makes up the flux Iup is not visible, but infrared. Now put the sphere inside a larger glass sphere, made of a glass that is transparent in the visible but partly absorbing in the infrared. So Iin watts/m2 still comes through, but not all the Iup makes it out. A fraction is absorbed and–in equilibrium–reradiated in all directions: some out, some back in. As a result of this, the total Iout is not equal to Iup anymore. Let us say it is equal to 0.8*Iup. So what happens?
Well, since in equilibrium we need to balance things, we need the total radiation out to equal the radiation in,
Iout = Iin
but Iout is only 80% of the radiation emitted upwards by the sphere,
Iout = 0.8*Iup
so we end up with
Iup = Iin/0.8 = 1.25 Iin
which means the “earth” has to radiate more with the glass in place, which means it has to get hotter.
Now tell me exactly what part of “CO2 traps part of the infrared radiation in the atmosphere” you think is untrue.

There’s a throwaway remark in the article “Even Internet sites that are said to have a good scientific level like “Science of doom” publish statements similar to those quoted above .” I wonder if anyone could point me at some specific examples of this from “Science of doom”?
Thanks.

“In the case that somebody asks why there is no peer reviewed paper about this issue , it is because everything what follows is textbook material.”
__________________________
The fact that today’s “science” of AGW is quite murky and has a disgusting odor therefore suggests that scientists of all stripes are not policing their turf well at all, and are themselves therefore very complicit in the “political” shenanigans that have been going on for the past 30 years. If it ain’t the math it must be the money. Why else would so many do so little to stop so few from making a mockery of their profession? For the right price, you can get anyone to do or say anything you want; especially in today‘s world. Now we know how Lot felt.

Jan says:
August 5, 2010 at 4:33 am
As I don’t understand this post, am I supposed to take it to prove that climate change doesn’t exist, as any argument will suit this purpose?
__________________________________________________________
No that is the whole point of this blog. If you do not understand the post ASK QUESTIONS! or google the terms you do not understand.
This post is more or less a mathematical proof.

6,000 ppm of CO2 in the atmosphere of Mars does not create any measurable “greenhouse effect”. Its black body T = its actual T = 210K. Without digging into theory (and I am graduated analytical chemist specialized on spectral analytical methods), this is enough proof for me to believe, that IR active gas *alone* does nothing.
Mars: thin atmosphere (albeit composed of 95% CO2) –> no “greenhouse effect”
Earth: denser atmosphere –> some real “atmospheric effect”
Venus: 95x denser atmosphere than on Earth –> powerful “atmospheric effect”
No atmosphere – no “greenhouse effect”
We have such a joke: an ant and elephant are crossing the wooden bridge. Ant says: “What a clatter we do!”
For developing a “greenhouse effect”, you need the elephant – a bulk atmosphere. But then call it more properly “atmospheric effect”.

CO2, the gas we all EXHALE does not stay there just looking down to earth in the atmosphere, it enters into the living organisms chain, first to make GLUCOSE (Plants do breath CO2 ya know, and btw exhale O2- a gas we like to breath, ya know…), then cellulose, etc., etc. then we EAT those vegs in order to live, or cattle eats them to make the MEAT we eat, or chicken eat corn grains to make the EGGS YOU EAT scrambled every morning, ya know buddy….all these transformations USE the energy CO2 ATE first, the HEAT, ya know, which makes possible for YOU TO WALK AROUND , fool around, repeating, like a parrot, silly things like: “CO2 is a greenhouse gas”.
And, what you don’t know is that all this is BUSINESS it’s just an invention to take the money out from your work, from your pockets, for some guys up there, who you will never know, and who will enjoy it in some distant sunny beaches while you keep on working.
So WAKE UP!

Roger Pielke, Sr and Ben Herman on the Greenhouse Effect of CO2:
http://pielkeclimatesci.wordpress.com/2010/07/23/the-greenhouse-effect-by-ben-herman-and-roger-pielke-sr/
http://pielkeclimatesci.wordpress.com/2010/07/27/%e2%80%9cthe-greenhouse-effect-part-ii%e2%80%9d-by-ben-herman-and-roger-pielke-sr/

Merrick, I appreciate your cogent and respectful critique. Your comments are also well written given that they are probably composed as you type. I love debate that rises to this level.

Clyde Rhodes says:
August 5, 2010 at 7:36 am
“It seems to me that it is a circular argument to assume equilibrium in order to prove equilibrium. The whole point is that when energy is added to the system, that shifts the equilibrium. ”
Exactly. And when energy is continuously being added to – and lost by – the system, you never reach thermodynamic equilibrium, even locally, only at best a new steady state. Like pouring water into a bucket with a hole in it.

Tom,
I’m with you until your conclusion on your time symmetrical equation. You conclude that, because
CO2* + N2 ↔ CO2 + N2⁺
is time invariant, there is no net transfer of energy from CO2 to N2.
You noted, of course, that CO2* -> CO2 + y
Your system, more correctly, is
CO2 + +y CO2* + N2 CO2 + N2⁺ CO2 + -y
It is noted then, that +y are photons taken in by your gas system from whatever sources, and -y are photons emitted from your system. The case for “”heating” of the atmosphere” (or whatever scorned terminology) is thus the statement +y > -y, in terms of the system described. I don’t believe your time invariance of the middle relationship touches on the ability of either outer relationship to be asymmetrical, so your conclusion that conventional wisdom is truly incorrect on that basis seems to be a bit of a stretch.
Also,
CO2* + N2 CO2 + N2⁺,
you state that this relationship is time symmetric, however, the system more accurately described (for the purposes of this all brand new argument!) is
CO2 + +y CO2* + N2 CO2 + N2⁺ N2 + N2⁺,
where the last portion represents the probability asymmetry of N2⁺ decay modes. Given the markedly different partial pressures of the two gasses, it is much more likely that N2⁺ + N2 decays to N2 + N2⁺ than N2⁺ + CO2 decays into N2 + CO2*. Probability asymmetries suggest bulk movement of energy into the largest component of the medium.
Sorry for the verbosity, I look forward to constructive criticism of exactly where I’m wrong above.

I find it facinating just reading the comments. I can follow the physics and arguments but the disagreements are eye opening. We just don’t have all the answers do we?

(((MOD: PLEASE DELETE MY PREVIOUS POST AND THIS NOTE. THANKS GREATLY.)))
[Note: might help if you chose a different screen name, and used a working email address. You email is fake, no more posts from you until you fix it. see the WUWT policy page ~mod]
Tom,
I’m with you until your conclusion on your time symmetrical equation. You conclude that, because
CO2* + N2 ↔ CO2 + N2⁺
is time invariant, there is no net transfer of energy from CO2 to N2.
You noted, of course, that CO2* » CO2 + y
Your system, more correctly, is
CO2 + +y «» CO2* + N2 «» CO2 + N2⁺ «» CO2 + -y
It is noted then, that +y are photons taken in by your gas system from whatever sources, and -y are photons emitted from your system. The case for “”heating” of the atmosphere” (or whatever scorned terminology) is thus the statement +y > -y, in terms of the system described. I don’t believe your time invariance of the middle relationship touches on the ability of either outer relationship to be asymmetrical, so your conclusion that conventional wisdom is truly incorrect on that basis seems to be a bit of a stretch.
Also,
CO2* + N2 «» CO2 + N2⁺,
you state that this relationship is time symmetric, however, the system more accurately described (for the purposes of this all brand new argument!) is
CO2 + +y «» CO2* + N2 «» CO2 + N2⁺ «» N2 + N2⁺,
where the last portion represents the probability asymmetry of N2⁺ decay modes. Given the markedly different partial pressures of the two gasses, it is much more likely that N2⁺ + N2 decays to N2 + N2⁺ than N2⁺ + CO2 decays into N2 + CO2*. Probability asymmetries suggest bulk movement of energy into the largest component of the medium.
Sorry for the verbosity, I look forward to constructive criticism of exactly where I’m wrong above.

merrick says:
August 5, 2010 at 4:32 am
. . . This is a blackbody at equilibrium. Now, add a source at greater than 15C (like a warm earth surface) and ad long as the rate of incoming 15 um radiation is greater than the 15 um radiation rate you already measured from your hohlraum there will be disequilibrium and the temperature of the hohlraum (not just the CO2 but all of the gas) will increase until the hohlraum is again emitting the same amount of 15 um radiation as is coming in. . . .
Merrick, please help me on this (I think) last of your comments;
If you add additional heat the whole experiment does indeed fall apart. But I think that misses the point; if you’ve got a hollow sphere, filled with a mixed gas at equilibrium at a certain temperature, and then you replace some of the gas with CO2 (raise the concentration) does the sphere necessarily retain more heat? I thought he did a good job of explaining why (at least very locally) this is not really possible. You will change the level of equilibrium of the several forms of heat transfer, but that’s just the speed that the heat moves around. The temperature itself will not change. Or is that not correct?
Can you please explain, by way of increasing the concentration of CO2 in the sphere, rather then increasing the amount of heat being added, how he is incorrect in his analysis. The way I read your comment (applied to the real world) is that if the Earth’s surface would get warmer, so would the atmosphere. That is an argument I would probably tend to agree with, though many on the AGW side of this debate have denigrated the notion that the Sun’s variations aren’t really responsible for the recent increase in global surface T, so I’m not sure your argument is fruitful in that regard.
Thanks.

Well, as a non-scientist, here’s my take from the comments thus far, right or wrong:
1. The people who know what they’re talking about are making technical comments that they claim rebut the original article.
2. The people who don’t know what they’re talking about are making comments along the line of: “Thanks, Tom, good to have that all clearly stated, great effort, puts it all to rest, I’ll have to set aside time to really absorb what you’ve explained so elegantly, etc.” (paraphrasing all, so as not to insult any one particular individual.)
Leaving me with an unchanged opinion that goes as follows: Apparently the human-caused increase in CO2 is heating the planet to at least a minor degree, but probably not to any degree worth getting exercised over. In the end, the next ice age will still prevail, no matter how much CO2 we pump out by burning fossil fuels, and that ice age will be caused by the same cyclical factors that caused the others. The trick is in the meantime to avoid impoverishing ourselves attempting to avoid a scare trumpeted by people who desire additional, even complete, control over our lives, helped along by their useful idiots. (I’ll leave it to the individual alarmists to decide whether they desire control, or are simply one of the useful, but those will eventually prove to have been the only two choices in my view of the matter.)
Note that I consider myself a skeptic even though I grant that we are probably subtly adding to the earth’s temperature by burning fossil fuels. My skepticism revolves around the politics/economics of the situation, and the corrupting of science as a means to reach ends that I find objectionable.

For this to be true it would have to be accepted as the dinosaur killer of AGW’s foundation. Somebody would have noticed that by now. I fear something you are sure of is wrong.
I eagerly await Part II.

Roy Spencer says:
August 5, 2010 at 4:57 am
If local thermodynamic equilibrium exists in a certain volume of a gas, and you add more CO2 at the same temperature, it is true that the volume’s temperature will not change.
No one I know of would disagree with this.
But it’s when that volume is exposed to outside influences — like IR radiation from the solar-heated surface of the Earth passing through that volume — that a temperature change can occur as a result of adding more CO2 to the volume.
_______________________________________________________________
Tom Vonk is not talking about anything but what he has defined. Until the idea of “local thermodynamic equilibrium” and the physics that applies to it is understood you can not discuss anything else. I think this post comes under the heading of defining terms.
As you said “No one I know of would disagree with this.” but most lay people do not understand that.

Mike Haseler wrote:
(24) The complex bond structure within CO2 means that it can readily absorb and emit radiation in the infra-red (IR) band where thermal radiation is given off by a blackbody9 at the temperature of the earth. Much of this IR is at wavelengths at which other atmospheric constituents do not interact, so if CO2 is exposed to a warmer surface like the earth, it will absorb radiation that would otherwise pass through into the cold of space AND likewise if CO2 is exposed to the cool of outer space it will emit vast quantities of IR at wavelengths which other gases cannot emit.
(25) When CO2 is present low in the atmosphere, it tends to block transmission of these wavelengths into space and reduce heat loss to space. When CO2 is present high in the atmosphere, it helps emit IR, so causing cooling of the atmosphere acting as a vector by which other gases can lose heat into space. Like triple glazing, the system is complicated by the movement of air. Air warmed at the surface naturally tends to rise above the majority of the (blocking) atmosphere and it cannot descend until it has cooled by the emission of IR into the cool of outer space. CO2 cooling is as natural as CO2 warming, the atmosphere being a highly dynamic and complex system: a natural cooling system taking heat from the surface of the earth up into space via convective currents.
(26) Simple physics could suggest CO2 is a cooling gas as easily as warming and “obvious” assertions must be validated against real evidence, not the preconceptions of “scientists”. CO2 could impact the atmosphere in other ways: changes in specific heat capacity, density, interaction with water droplets and cloud formation. Other gases like water vapour also have their effects. It would be wrong to say that increases in CO2 can not affect the climate, but it is equally absurd, in such a complex system, to say this or that effect must dominate in the absence of the normal rigorous testing required by science.
I would recommend this simple summary to anyone who is trying to understand the effect that CO2 has or might have. I have tried to make the same points in the past but the above statements are more succinct.
Just to embelish a few of the points.
The evidence from recent ice ages suggests that periods with high CO2 concentrations correlate with periods of cooling (but could easily be coincidental). There is absolutely no correlation with warming periods.
At low altitude CO2 absorbs most 13 -18 micron radiation within a few feet and re radiates it in all directions. The energy radiated downwards warms the earth (and air) below whilst that radiated upwards gets absorbed by other CO2 molecules and reradiated… and so on. Just below the tropopause the density of CO2 is such that there is a high probability that upward directed radiation will be emitted to outer space. This radiation from just below the tropopause represents the nett loss from the earth at that wavelength. It represents 18% of all the energy radiated from the earth. Most of the remaining 82% is radiated by water vapour molecules from various heights in the atmosphere (depending on wavelength) and the surface of the earth (particularly at wavelengths around 10 micron where the atmosphere is almost transparent).The total energy radiated by all these three (plus a few other small contributors like methane) has to balance the sun’s energy absorbed by the earth during the day. If it does not the earth will either heat up or cool down until it does.
I therefore have two questions that I have yet to get answers to:
1)Has amount of energy radiated into space at 13-18 micron reduced over the past 30 years? This is what make AGW a theory because it can be disproved if there has been no decrease.
Since this cannot be easily measured until the next generation of satellites goes up this year an alternative question could be:
2) Has the CO2 layer radiating directly into space decreased in temperature? The increased number of radiating CO2 molecules will have increased the radiation into space so the temperature will have to decrease significantly to compensate for this increase and reduce radiation still further.
The climate4you website has a section on long wave radiation which is very informative. It also shows how difficult it is to answer the first question. The global average of long wave radiation measured by satellites fluctuates by +/- 20%. This fluctuation dwarfs the tiny change that we are trying to measure over the longer term.

DocWat says:
August 5, 2010 at 5:23 am
Help me here… A system in equilibrium quickly returns to equilibrium at a higher level when it absorbs an IR photon: CO2+N2CO2+N2 becomes CO2*+N2CO2+N2+ (pardon the limited special character skills). This looks like heating to me, and, the temperature is controlled by the variance in the rate of absorbed and emitted IR photons for any small volume.
What I really don’t understand is why water and CO2 are better, by a factor of 20, at this as N2 and O2
___________________________________________________________
I am going to go out on a limb and drag up my physics from forty years ago (Eeek is was that long ago?!)
The absorption of a photon does not translate to heat it is the VELOCITY of the gas translates to heat. PV=nRT
Temperature: A measure of the amount of heat in a system
[K] or [◦ C]. More precisely, it is a measure of the average velocity
of the particles in matter (see §XIII.G). from PHYS-2010: General Physics I: Course Lecture Notes: Section XIII
Hope that helps.

Jan K. Andersen says:
August 5, 2010 at 5:23 am
I am sorry to say that this was a rather disappointing article on this otherwise excellent blog.
The fact that CO2 absorbs infrared energy and heat the atmosphere is no theory,, it is a fact. The flaw in the article is that it does not take into account that the absorbed radiation is outgoing, but the emitted radiation go in all directions.
_____________________________________________________________-
There IS no flaw. Tom Vonk carefully defined the case he was discussing. I again defined the simple case under discussion here: http://wattsupwiththat.com/2010/08/05/co2-heats-the-atmosphere-a-counter-view/#comment-448340

A few questions for Tom Vonk:
Is it fair to say CO2 is an insulator that slows down how fast the ground cools at night?
Is it also fair to say that like any other insulator each fixed incremental addition of more insulation is less effective than the previous increment – so that like having on five layers of clothing in the arctic winter adding a sixth won’t help keep you warm nearly as much as going from no clothes to adding the first layer?
Does a 25ppm increase in CO2 from 1880 to 1950 have about the same net surface warming effect as the 50ppm increase from 1950 to 2000?
The big questions though are the ones you can’t answer. Is there a negative feedback to increasing CO2 (in the water cycle) that will negate its insulating effect? Latent heat of vaporization at the surface, especially over the oceans, carries a tremendous and not easily quantifiable amount of energy straight through the CO2 like it wasn’t there and releases it much higher up where the path out the door to space has much less resistance compared to ground level. Is the effect of higher concentration of CO2 i.e. the CO2 signal or fingerprint, hopelessly swamped by other variables, some cyclic and some chaotic, some probably unknown and possibly unknowable and greatly variable in just about any timeframe from minutes to millions of years?
I guess I’ll finish up with a biology and geology question. What is the global optimum average temperature for maximum productivity of the primary producers (green plants) in the food chain? What is the optimal concentration of CO2 for the same producers?
It seems clear enough from evidence of the geologic past that before the earth started ringing like a bell every 120K years from glacial to interglacial with the former dominating the other 10:1 in persistence, the Eocene optimum 50 million years ago the earth was ice-free, green from pole to pole, it was about 11F warmer overall, with the most dramatic warming in the highest latitudes (right where you’d want it if you could ask for it), and atmspheric CO2 was several times what it is today, which makes sense in light of much warmer global ocean not able to hold as much CO2. Happily enough, terrestrial also plants also require less water per unit of growth as CO2 rises because they don’t have to open their stomata as much to get the respiratory exchange of gases.
So what am I supposed to fear from rising CO2? A warmer, greener earth? I’m more looking forward to it!

Watch how fast Liquid Nitrogen absorbs infrared radiation/gains energy from the rest of the molecules in its space.

http://www.youtube.com/watch?v=uQJOj0PkFZU&NR=1

Folks, it would be fun to try grading all the responses. The fact is that Tom has made a fundamental error. Roy Spencer has pointed it out, as you might expect. Werner Weber and Edvin have added more detail on where he went wrong. There are probably others who have gotten it right but I didn’t notice as I read them.
OTOH, a lot of people have either taken Tom’s words as gospel or gone off on tangents. I’m interested in seeing if Anthony gets it right or not.
BTW, in case you didn’t get it, the basic error by Tom is demanding that there be LTE at all times, even when a photon of IR from outside the local area is absorbed. In fact, he’s also misleading when he claims that a violation of LTE means the temperature of the local area is undefined. I’d like to see it worked out quantitatively, but in any case, if we’re talking a reasonable size local area, the uncertainty of temperature by one or a few IR photons being absorbed is too small to worry about. It’s only when there’s a constant input of such outside photons being absorbed that the local area must warm to produce a new LTE eventually.
One more thing. when we’re talking warming the atmosphere by added GHGs, the initial action is that a local area will absorb a larger % of the (unchanged at this point) IR entering it. This will, despite what Tom says, warm the local area and cause it to, when a new LTE is reached, emit more IR in all directions. The added IR which reaches the surface will warm it (See Roy Spencer’s site if you’re one of those who don’t think a colder body [atmosphere] can warm a hotter body [the surface] via radiation) and this is the raw material of the climate change theory. The CAGW crowd then make a number of wrong assumptions at this point, but I think all the skeptics here are quite aware of that.

Gail Combs says:
August 5, 2010 at 8:27 am
“Tom Vonk is not talking about anything but what he has defined. Until the idea of “local thermodynamic equilibrium” and the physics that applies to it is understood you can not discuss anything else. I think this post comes under the heading of defining terms.”
No system that has net radiative energy flows can be in LTE. It may be quite close to LTE, but the departures from LTE cannot be neglected when considering radiative heating and cooling. LTE is not a valid or relevant assumption for discussing the greenhouse effect. It is important to distinguish LTE (local Thermodynamic Equilibrium) from LDE (Local Dynamic Equilibrium), which merely means the temperatures, pressures, composition, inputs, outputs, etc., aren’t varying (or varying only on timescales much greater than that of the molecular processes concerned).
Note that within Earth’s troposphere, the gross molecular flow of heat energy through any surface is of order 100MW/m2 (heat content times molecular speed). The net energy flows (radiation, convection, etc.) are however only ~300W/m2, a few millionths of the total. Being so comparatively small, they normally produce only very slight departures from LTE. Nevertheless, they are quite adequate to create and maintain strong vertical temperature gradients and major temperature differences across the globe.

DocWat says:
August 5, 2010 at 5:23 am
Help me here…
What I really don’t understand is why water and CO2 are better, by a factor of 20, at this as N2 and O2
________________________________________________________
It has to do with the shape of the molecule. CO2 is
O-C-O and can bend a little in collisions so it is no longer symmetrical
Water, H2O, is not linear like CO2 but shaped in a V (hope the drawing works)
H…. H
\ O /
N2 is N =N (triple bond) and O2 is O=O (double bond)
O2 and O3 grabs much higher energy wavelengths from the sun
This gives a picture of what molecules grabs which wavelength of energy from where (sun or earth) and a ball park of how much.
http://upload.wikimedia.org/wikipedia/commons/7/7c/Atmospheric_Transmission.png

This post is an insult to honest climate skepticism. The author’s thesis is correct, but incomplete, and therefore totally irrelevant to climate. “A volume of gas in Local Thermodynamic Equilibrium (LTE) cannot be heated by CO2” UNLESS MORE PHOTONS ENTER THAT VOLUME THAN LEAVE. WHEN more photons enter than leave, then that gas will heat up until it radiates away as many photons as it receives. Of course, carbon dioxide can’t heat the atmosphere by itself – it needs an outside source of energy!
Radiant energy is constantly FLOWING from the sun to the earth’s surface and atmosphere and from the earth’s surface and atmosphere to space. Within the atmosphere energy flows by both radiation and convection. The temperature at various locations in the atmosphere and on the surface of the earth is determined by the net flux of energy at that location (and never reaches true equilibrium because the energy input from the sun changes with night/day and the seasons). We are now conducting a planet-wide experiment to see what happens when we double the concentration of the most important molecule mediating the flow of energy from the upper atmosphere to space. (There is little water vapor in the upper atmosphere and most energy leaves the lower atmosphere by convection to or radiation to the upper atmosphere.)
Tom Vonk is correct when he says that the following statements are over-simplifications and need corrections (in caps): “CO2 absorbs AND EMITS the outgoing infrared energy and warms the atmosphere TO A HIGHER TEMPERATURE THAN IT WOULD HAVE WITHOUT CO2” – or – “CO2 traps part of the infrared radiation between ground and the upper part of the atmosphere” AND IS THE MAJOR SOURCE OF INFRARED RADIATION FROM THE UPPER ATMOSPHERE TO SPACE. The credibility of the skeptical community is not helped when Tom makes similar over-simplifications and then buries the important qualifications in Caveat 1: “The concentrations of CO2 (and H2O) play a role in [the] dynamics [of the Earth-atmosphere system] but it is not the purpose of this post to examine these much more complex and not well understood aspects.” What is the purpose of Vonk’s post: To correct the over-simplifications of CAGW’s or to confuse readers into thinking that CO2 plays no role in the temperature of the atmosphere? The future climate of the planet depends on these “much more complex and not well understood aspects”.

[snip]

Paul Birch says:
August 5, 2010 at 9:43 am
No system that has net radiative energy flows can be in LTE. It may be quite close to LTE, but the departures from LTE cannot be neglected when considering radiative heating and cooling. LTE is not a valid or relevant assumption for discussing the greenhouse effect. It is important to distinguish LTE (local Thermodynamic Equilibrium) from LDE (Local Dynamic Equilibrium), which merely means the temperatures, pressures, composition, inputs, outputs, etc., aren’t varying (or varying only on timescales much greater than that of the molecular processes concerned)…..
________________________________________________________
I do not disagree. However you still have to define LTE (local Thermodynamic Equilibrium) and its physical characteristics before you can go on to describe LDE (Local Dynamic Equilibrium) were things ARE varying.
I think both side of the discussion should be looking at Tom’s definition of the LDE (Local Dynamic Equilibrium) AS an Equilibrium. Jump on him if his definition of LDE (Local Dynamic Equilibrium) and the physics of that state is incorrect otherwise jump on him when he finishes defining his terms and goes on from there.
Many of us have little or no thermodynamics or even physics or chemistry background so I find this definition of terms highly useful in advancing my knowledge.
So please stick to the very small portion of Thermodynamics, LDE (Local Dynamic Equilibrium) Tom has described. Is Tom’s description of this equilibrium state wrong and if so where and why.

Seems like we’ve got a good peer review process going on here.

stevengoddard says:
……”There isn’t any question that the greenhouse effect is real and that CO2 is a contributor. Places that have very little GHG (i.e. South Pole) also have very cold temperatures.”………..
CO2 is well mixed in the atmosphere.
Strangely enough even at the South Pole the H2O / CO2 backradiation ratio is at 2.6.

The argument sounds to me like the following: A system (x) with CO2 and N2 under bombardment from IR will establish an equlibrium state with temperature Tx.
But this does not show the conclusion. In order to show the conclusion, two systems (a & b) under bombardment from the same amount of IR but with different CO2 concentrations must establish the same equilibrum state with temperature Ta = Tb.
So, Mr. Vonk, do they?

Physics in the macroscopic world gets real complicated real fast trying to analyze it at the quantum scale. I don’t think it’s worth trying and I’ve read a lot of equally credentialed physicists disagreeing about all sorts of stuff at the quantum level. One of my favorites keys off of time invariance mentioned in the OP. That leads to there being no such thing as time it’s merely an artifact of the law of entropy. It also leads to there being no way to destroy information such that if I burn every physics textbook in the world all the information in them is still in the universe recorded in completely time reversible quantum interactions. It implies that information obeys the same law of physics as energy – it can’t be created or destroyed but only change form and obey the laws of entropy while doing it. It also implies that maximum order in the universe was at the big bang and law of entropy has been taking its toll ever since. It also implies that the information content of the observable universe, if it’s a closed system, is invariant. Even more it tends to support a deterministic universe because every quantum change since the big bang is time invariant and so you can theoretically calculate every moment in the future and every moment in the past from a perfect snapshot of the quantum state of the universe at any point in time. Good luck with that though as there’s an estimated 10^80th particles in the universe and the math gets untractable when you have more than 3 particles in your closed system. Heck, even calculating precise gravitational interactions in a 3 or more body system becomes intractible and shortcuts have to be taken to get practical solutions for deep space exploration. There’s weird crap happening far out in the solar system on Voyager and Pioneer spacecraft not being at the position and velocity where theory says they should be and radiothermal power supplies not decaying at rates predicted upon what are axiomatically constant radioactive decay rate of the isotopes like it isn’t really a constant at all.
There are a great many unknowns in physics. People like to think we have a good handle on all of it and that’s simply not the case.
There are more things in heaven and earth, Horatio, than are dreamt of in the standard model.

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 with cell contents and source at the same temperature, the spectrophotometer will see the same blackbody curve and total energy 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 by continuously removing energy from the cell and emission peaks if the cell is maintained above T by adding energy. We see a greenhouse effect (higher surface temperature) at the Earth’s surface 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 increase to get the same flux at the detector (space) that would be present if the atmosphere were perfectly transparent.

Gail Combs says:
August 5, 2010 at 10:17 am
“I do not disagree. However you still have to define LTE (local Thermodynamic Equilibrium) and its physical characteristics before you can go on to describe LDE (Local Dynamic Equilibrium) were things ARE varying.”
In neither LTE nor LDE are conditions varying. The difference is that in LTE (which Tom relies upon in his analysis) there cannot be any net radiant fluxes. If there is any anisotropy in the radiation at any wavelength then one does not have LTE, one does not have complete equipartition, there is a net entropy increase and the system is not invariant under time conjugation, so Tom’s analysis is fundamentally invalid. Without realising it, he is trying to apply LTE rules to a system that is not in LTE but only LDE.
It’s not necessary to understand LTE or the complex absorption and heat transport modes to understand the greenhouse effect. In my view, it’s less confusing simply to look at the transmission of radiant energy through the atmosphere. If sunlight can get in more easily than thermal radiation can get out, then the surface will get hotter (and radiate more fiercely) until enough thermal radiation does escape to balance the incoming energy. The key parameters are the transmission and reflection coefficients for sunlight versus long wave thermal radiation (it’s rather like an electrical circuit). But we don’t need to get into the gory details to see that the greenhouse effect of CO2 in the Earth’s atmosphere is small, or that the effect of water vapour is large; just go outside on a clear and a cloudy night in winter and you can feel the difference for yourself.

Dear Dr. Tom:
Please use this reference:
Dr. Elsasser’s classic, “Infrared Heat Transfer in the Atmosphere” is available at ScribeD.
http://www.scribd.com/doc/34962513/Elsasser1942
Page 23 is rather interesting! It says: “It may be noted that since the flux in the carbon dioxide bad is equal at any level to a definite fraction of the black body radiation corresponding to the temperature at that level both in upward and downward directions, the RESULTANT (emphasis Elsasser’s) the of the carbon dioxide radiation vanishes in the approximation of the chart (Elsasser’s General Radiation Chart, used to calculate daily heat up and cool downs based on T,P and RH recorded by Radiosone balloons at multiple levels to 50,000 Ft.) This is a fair approximation to the truth in the lower atmosphere. For the upper atmosphere see section 12). (In section 12, CO2 is taken for “upper atmosphere” …or generally stratosphere, as an overall UPFLUX agent, or cooling agent. This has to do with the shape factor relation between the 4 Pi steradians of “view” and the percentage “seen” by “space” versus that “seen” by the Earth’s surface…)
I think that if the dear Dr. will take some time with this classic, he will be asking, as I do…”When did CO2 become net “downflux”? At what levels, and how intense. And what changed in the basic physics….which (let us not be “temporal provincialists” here) were well worked out by theory and observation by 1942???
Happy downloads.

Thanks Tom, for a good thought provoking article. One issue I have is that although I think that CO2 and water vapour cause a very small increase in temperature, the amount of extra energy retained is so small that the effect on climate/weather is imperceptible.
Jurai made some interesting points very eloquently, with which I am in complete agreement:-
“Juraj V. says: August 5, 2010 at 7:25 am
6,000 ppm of CO2 in the atmosphere of Mars does not create any measurable “greenhouse effect”. Its black body T = its actual T = 210K. Without digging into theory (and I am graduated analytical chemist specialized on spectral analytical methods), this is enough proof for me to believe, that IR active gas *alone* does nothing.
Mars: thin atmosphere (albeit composed of 95% CO2) –> no “greenhouse effect”
Earth: denser atmosphere –> some real “atmospheric effect”
Venus: 95x denser atmosphere than on Earth –> powerful “atmospheric effect”
No atmosphere – no “greenhouse effect”
We have such a joke: an ant and elephant are crossing the wooden bridge. Ant says: “What a clatter we do!”
For developing a “greenhouse effect”, you need the elephant – a bulk atmosphere. But then call it more properly “atmospheric effect”.”
Trying to isolate any bits of our weather/climate, which is a highly complex turbulent system, is fraught with difficulty. Only by investing in much, much better geographic instrument granularity and in the quality of data will the hard problem of understanding climate be solved – politics and carbon tax permitting!

Karel says:
August 5, 2010 at 10:52 am
Sorry guys, but I’m not nearly smart enough to understand this post. Anyone game for a layman’s translation ?

Yeah, CO2 is like insulation in the home attic. It slows down the rate at which energy can move across it from warmer to colder.
And it does a damn poor job of it because it only slows a small fraction of the total energy moving across the boundary and does nothing to slowing down a major way that energy is transported in the fluid turbulent atmosphere – convection – whereas the roof over your head pretty much eliminates all convection, all radiation, and forces the energy to move through it by conduction alone.

“What is the percentage of water vapor at the south pole?”
Not sure if the figures are totally accurate as it’s hard digging up average absolute humidities over different regions.
Absolute humidity 0.03% at South Pole.
The Sahara desert by contrast is 0.3% and temperate latitudes over land vary between low of 1% and high of 5%. Wet tropical climates and over the oceans is 5% or more on average. That’s near the surface however. At altitude it freezes and/or condenses out to very dry air then you get ice crystals that raise albedo, clouds that raise albedo, and cool rather than warm what’s underneath.
But keep in mind when water freezes high in the atmosphere there’s a fair amount of latent heat released when water at freezing point becomes ice at freezing point (lots of heat released with no change in temperature). Not as much latent heat as is released by condensation of water vapor into liquid water at the same temperature but still a lot.

Dave Springer,
Antarctica receives more solar insolation than any place else on the planet during December, yet temperatures there remain far below zero.
http://earthobservatory.nasa.gov/Features/EnergyBalance/images/annual_solar_insolation.png
The lack of a greenhouse effect keeps temperatures very cold there.

Nylo says:
August 5, 2010 at 5:51 am
By the way, CO2 doesn’t heat, that’s true, and that makes your small experiment work. What it does is slow down the cooling of the surface of the Earth. It reduces the net radiation at 15um. As a result, you get higher temperatures than you would have without CO2. But all the initial heat came from the Sun, of course.
I am uncomfortable with the statement CO2 slows down the cooling of the surface of the Earth.
To me, a “slowing down” of the cooling of an object means less energy per unit time leaves the object. Assume a fixed rate of energy per unit time is being absorbed by and/or generated within an object; and at temperature T the object is in “heat transfer” equilbrium–i.e., the amount of outgoing energy per unit time is equal to the incoming radiation per unit time. If you “slow down the cooling”, aren’t you decreasing the rate at which energy leaves the object? But if you slow down the cooling without decreasing the rate of energy input, as a function of time the object must retain more and more heat. The object will stop retaining heat only when the outgoing rate of energy equals the input rate of energy. A rise in object temperature may be the mechanism that re-establishs input rate/output rate equality; but once reached, the outgoing rate of energy will be equal to the input rate of energy (which hasn’t changed) and hence cooling (or the rate of cooling) will also unchanged. As such, it may be correct to say that CO2 may temporarily affect the rate of cooling, but without a change in the rate of energy input, eventually the rate of cooling will return to its original value, at which point the “cooling” has not been “slowed down”. Bottom line, CO2 has been added but for a fixed rate of energy input, the “cooling or rate of cooling” is unchanged.

Merrick says:
August 5, 2010 at 7:15 am
Sorry, just need to weigh in one more time.
That’s better ! I’m a physicist but was having great difficulty with this essay.

Jan K. Andersen says:
August 5, 2010 at 12:28 pm
Well I consider myself as an AGW skeptic, but I’m not a skeptic to the existence of a natural greenhouse effect. Tom Vonk says in essence that no greenhouse effect can exist.
There will be no ‘greenhouse effect” if the IR is ‘given up’ in sufficiently small timescales. So what I think I’m trying to say is that when a mole absorps radiation in the IR in translate to the first excited level and falls back to the ground state within a fraction of a second.
That is a very poor description but I’m tired and fed up.

Karel,
Yeah, I’ll take a whack at it.
Someone made an attempt to describe something, and a bunch of intelligent people decided it was darned near fraudulent, or something.
Because arguing in good faith is evidently not scientific enough?
Hey, you ruffled feather types: just deal with the argument and stop assuming some fraud is being perpetrated. Make your case and let the guy respond.

LOL. I think y’all will find that Vonk really understands this physics. Can’t wait for his responses!
“stevengoddard says:
August 5, 2010 at 8:43 am
bushy,
There isn’t any question that the greenhouse effect is real and that CO2 is a contributor. Places that have very little GHG (i.e. South Pole) also have very cold temperatures.”
And places like Phoenix also have relatively low amounts of GHGs, yet have very hot temperatures (relative to Atlanta, which is at virtually the same latitude and altitude, but which has over 3 times as much GHG). Are you forgetting about solar insolation?
Why do so many folks keep trying to explain atmospheric temperatures with only infrared radiation? What about heat storage, convection, conduction? No matter what you believe about the greenhouse effect, it is only ONE effect!

JAE
The absolute humidity in Phoenix is orders of magnitude higher than Antarctica.
I have been in Phoenix when the dew point was over 70F. Even on a dry day, there is plenty of water vapour.

John W. says:
August 5, 2010 at 5:04 am
“II have some questions:….”
John W, why do you have these questions? Because you must rely on authority?

Tom V;
Thanks for that. I think however that many people will miss the point.
can you explain for folks what you mean by this? and how this caveat related to AGW.
Also, Just for the record, do you accept the fundamental physics of RTE’s
Or simply, to a first order, what is the impact of having more C02 or H20 or any GHG in the atmosphere?
The Caveat that needs some explantion:
Caveat 1
“The statement we proved cannot be interpreted as “CO2 has no impact on the dynamics of the Earth-atmosphere system” . What we have proven is that the CO2 cannot heat the atmosphere in the bulk but the whole system cannot be reduced to the bulk of the atmosphere . Indeed there are 2 interfaces – the void on one side and the surface of the Earth on the other side . Neither the former nor the latter is in LTE and the arguments we used are not valid . The dynamics of the system are governed by the lapse rate which is “anchored” to the ground and whose variations are dependent not only on convection , latent heat changes and conduction but also radiative transfer . The concentrations of CO2 (and H2O) play a role in this dynamics but it is not the purpose of this post to examine these much more complex and not well understood aspects .”

Well Tom, I understood most of what you wrote; but I am not sure I can agree with your conclusions.
CO2 consists of only one in about 2570 molecules of the atmosphere so CO2-CO2 collisions are highly unlikely, and CO2-N2 and CO2 O2 collisions ought to occur in about 4:1 ratio.
But N2-N2, and N2-O2, or O2-O2 collisions are far more likely.
So a CO2 molecule colliding with either a N2 or an O2 molecule is highly unlikely to encounter the same N2 molecule again and retrieve the exchanged energy.
Yes I know you said that LTE is assumed; but how real is that in an open atmosphere with convection currents as well as both a Temperature gradient, and a density gradient.
Which brings to mind another question.
A solid material; say ice for example can and does emit black body like thermal continuum radiation since it is above absolute zero. Heat it above zero deg C and it becomes a liquid and continues to emit a continuum thermal radiation with a roughly black body spectrum and Stefan Boltzmann output.
But perish the thought that you should heat the water to above 100 deg C whereupon it becomes a gas, and immediately stops radiating thermal radiation; because everybody knows; or seems to think that gases do not emit black body like thermal radiation.
Of course nobody explained this to the sun; or the argon or other gas in a gas filled incandescent light bulb. By some miracle, a very large fraction of the broadband radiation emitted from a gas filled lamp comes from that very gas filling, which of course can’t emit BB like continuum radiation.
A consequence of the model you have proposed would seem to be that the “back radiation” due to CO2 interception of surface emitted (from solid or liquid continuum thermal radiation can consist only of the specific wavelengths that the CO2 absorbed in the first place; since you say no net energy is exchanged between the CO2 and the Atmosphere.
I agree with your contention that symmetrical non polar molecules do not interract with the IR radiation; but in collisions, even symmetrical polyatomic molecules become polar, and therefore can absorb and radiate.
By the same token, in collisions even symmetrical molecules like N2 or O2 can exhibit an accelerating electric charge and therefore emit EM radiation in a continuum spectrum.
Do you have a rigorous QM proof that gases do not emit ordinary BB like thermal continuum spectra just like any other material above absolute zero does ?
No I am not asking for your proof here; just do you have or know of one ?
If I accept your premise that the trace GHG gases do not transport thermal energy to the ordinary atmospheric gases; then that of course would apply to H2O as well; so how come we are not that frozen ice ball.
In any case; the question seems to me to be moot, since there is general agreement that CO2 and H2O and other GHG molecules DO capture LWIR from the surface or other atmospheric layers; which must increase the net energy (and Temperature) of THAT layer.
So is it relevent that CO2 and N2 can’t unilaterally transport energy following your explanation; the atmospheric Temperature is nevertheless increased by the GHG captures.
I don’t see any assymmetry in your N2-CO2 exchange. On average the same applies to any two molecules so there isn’t any net transfer from one N2 molecule to another, or N2-O2 either.
But anyway’ I appreciate your explanation. Any insight is always better than none at all.
George

Nearly all of the details of the argument are correct but it fails because of a faulty assumption. The assumption is that all parts of the atmosphere are in perfect local thermal equilibrium. This is not the case.
In actual fact the atmosphere are in APPROXIMATE local thermal equilibrium.
There is a thermal gradient between the surface (25C) and outer space (-270C) and this cannot happen if there is LTE.

Paul Birch says:
August 5, 2010 at 2:02 pm
… Furthermore, it does not cause net ongoing cooling to offset the greenhouse warming because once the atmosphere has made that very slight adjustment it ceases to expand.
___
But that is exactly what I was inferring. The energy flux through any volume is equal after added GHG. It is only that initial increase in warming that persists, the warming doesn’t keep growing. But the expansion also persists at that new higher temperature in exact like manner. The expansion only has to account for some 0.7K/288K of the initial rise. I can’t seem to accurately calculate to see if this equates (my cry for expertise).

@ Paul Birch
First, thanks for the moment. Second… reset.
My response was wrong. Went out for a break going over my response to you in my mind and I realized it made no sense. I said ‘increased temperature’ where I should have said ‘increased radiation’.
Here is another way to look at my unexplained cycle, all happening in an one instant…
Increase a LW interacting GHG in the atmosphere… causes absorption / random radiation… the ½ down increases radiation pressure… atmosphere expands… thus it cools… BUT, radiation ½ down causes an increase in temperature… warming equals (??) the cooling? Neither is continuous but a static one time differential since all heat must still equate on both sides, ground absorption and LW at TOA.
See, that is the loop I cannot totally explain as I go over again and again. Spent months with this popping up in my thoughts now and then as I read the thousands of comments and papers I have absorbed in the last year.
There, that might explain it better.

dp
You are talking to the converted.
I think that H2O provides most of the radiative effects even in deep midwinter Antartica.

DR says:
August 5, 2010 at 7:20 am
I’d think the heat capacity of a CO2 molecule vs water vapor would be of importance. No?
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Totally. The heat capacity of water when it changes from liquid to vapor or vice versa is 50,000 times greater than that of the CO2 in a volume of atmosphere with 1% H20 and 500 ppm CO2. The temperature does not change. The BB does not change.

wayne says:
August 5, 2010 at 3:36 pm
“Increase a LW interacting GHG in the atmosphere… causes absorption / random radiation… the ½ down increases radiation pressure… atmosphere expands… thus it cools… BUT, radiation ½ down causes an increase in temperature… warming equals (??) the cooling? Neither is continuous but a static one time differential since all heat must still equate on both sides, ground absorption and LW at TOA.”
OK, let me try to explain for you. “Increase GHG … atmosphere expands … thus it cools…” Fine so far, but note that the expansion due to radiation pressure is of order only 1 part in 1E11, so the adiabatic cooling is only of order 1 nanokelvin (and that much only if you go from optically thin all the way to optically thick). Really, really tiny. “… radiation down causes temperature increase … ” Yes. Other things equal, an increase in the absolute temperature of ~28% for an optical depth difference of one. So ten trillion times as big as the cooling! Now the radiation pressure in the cavity between surface and absorber has increased by a factor of 2.7, due to the higher temperature, but the additional expansion and cooling this causes is still utterly negligible (a further 1.7 parts in 1E11). The warming of the atmosphere in the cavity also causes thermal expansion (of 28%). Note that the temperature reached within the cavity is unaffected by the expansion of the atmosphere, or the (~10%) adiabatic cooling temporarily caused thereby; it just takes a little longer to heat up to its final value; the extra energy is stored in the greater gravitational potential energy of the expanded atmosphere. Once the system reaches a state of dynamic equilibrium the energy lost by the ground equals the energy reaching the ground.

Jeffid,
Brilliant.

Rob R
I go up to 14,000 feet pretty regularly in the summer, but have yet to encounter temperatures of -40C . Normally they are about 40-55C warmer than at the same elevation in Antarctica, even though Antarctica receives more solar insolation.

I believe what is missing from this article and perhaps much of the work of many in this field is an equal focus on the cooling effect of Earthshine emitting and absorbing (i.e. greenhouse) gases. For each ‘greenhouse’ gas there must be some altitude at which half the photons emitted going straight up escape to outer space. I am somewhat puzzled that this or an equivalent mean escape altitude is not a well known parameter for each of the Earth’s greenhouse gases.
Once energy from CO2 and H2O begins to leak into outer space, LTE is violated, temperatures *must* fall until a more global thermal equilibrium is established with incoming thermal radiation and convection. At the 15µ band, solar radiation has diminished to an insignificant trickle and this allows temperatures at the tropopause level to be extremely cold (average -56.6 deg C.) such that the normal adiabatic lapse rate makes life possible at the surface.
At about 90 km up, I note that the atmosphere of Venus cools down to very low temperatures in the vicinity of -112 deg C. I suspect this is the CO2 thermal radiation escape altitude there.

stevengoddard says:
August 5, 2010 at 6:04 am
Nice presentation, but an incorrect conclusion.
Would you be so kind as to tell me how is it that the conclusion is incorrect?
I have calculated the totabs and toemiss of carbon dioxide and other gases in the atmosphere through several well-known algorithms (T, σ and ρ) and found that the carbon dioxide cannot be a warmer of the atmosphere either the surface by any means.
Ira says:
August 5, 2010 at 6:53 pm
…I am also concerned about the long-term effects of the continuing rapid rise in CO2 levels, perhaps half of which is due to human activities… Indeed, the only readers who will accept Tom’s argument are those who understand none of it but happen to like the conclusion they think he has “proven”.
I am not concerned about the CO2 levels. CO2 is good for life. I understand Tom’s argument and accept it because, as I have told to Steven Goddard, the physics of thermal energy transfer supports the Tom’s argument.
Just to give an example, the mean free path length of photons in the CO2 at its current density in the atmosphere is 48 meters. Isn’t it too long? Compare it with the mean free path length in water vapor, nitrogen, oxygen and argon at their actual densities in the atmosphere and you’ll find the roots of AGW mistakes.

RE: Caleb: (August 5, 2010 at 6:10 pm) “However I crave to have water vapor included in this sort of discussion.”
As the concentration of gaseous water (water ‘vapor’) in the atmosphere is on the order of 3o,000 to 40,000 ppm, this trace greenhouse gas really *is* the invisible 800 lb gorilla in the room even if we ignore the phase change effects.

Hi again Tom,
Thanks for this interesting article. I found it enlightening re how different competent people have been saying things that seem inconsistent, but now the question is, have you got it right?
I followed you until, roughly, this point:

The LTE conditions with the energy equipartition law give immediately the answer : “These rates are exactly equal .” This means that for every collision where a vibrationally excited CO2* transfers energy to N2 , there is a collision where N2⁺ transfers the same energy to CO2 and excites it vibrationally . There is no net energy transfer from CO2 to N2 through the vibration-translation interaction .

The problem here is that the energy equipartition law is a statistical result, not a precise law such as “Action and reaction are equal and opposite.” An abundance of transfers one way or the other are expected and will happen, all they do is increase the probability that an increase in transfers the other way will restore the equilibrium sooner or later. But talking about a single interaction necessitating an interaction in the opposite direction? No.
Here is the complete interaction sequence, in which I label the three states:
CO2 + γ + N2 (state A) ↔ CO2* + N2 (state B) ↔ CO2 + N2⁺ (state C)
All three states are in equilibrium for some given composition of the components. Photons (state A) will be absorbed giving excited CO2 (state B) and the reverse, and excited CO2 will interact with N2 to give translationally more energetic N2 (state C) and the reverse. Accordingly, you tell us “For example only about 5 % of CO2 molecules are in a vibrationally excited state at room temperatures , 95 % are in the ground state.”
But that assumes the existing proportions of the ‘ingredients’. If more CO2 molecules were pumped into the atmosphere, then it might be, for example, that 6% would be excited and only 94% in the ground state. Similarly, if the photon flux were doubled, that would drive more CO2 into the excited state and in turn drive more energy into the N2 translational mode. The relative balances amongst states A, B, and C depends upon the concentrations of the components, in just the same way as with a normal chemical reaction: change something and the ratios of all the rest change too. For this reason, whilst I thank you for explaining something that has puzzled me, I don’t agree that your conclusion follows.

wayne says:
August 5, 2010 at 1:04 pm
My point to both of you is a huge point that is being missed here. Huge. Since the LW radiation from the ground is always in the azimuth hemisphere’s direction and ½ of the reemitted photons are in the nadir hemisphere, a radiation pressure exists here which will cause and infinitesimal but real expansion of the atmosphere which will exactly cause a temperature decrease that exactly counteracts any warming from the downward radiation. anna, I stated this in January or February and never could get you to see.
The sun hits the earth, there is radiation pressure, but the forces are so tiny with respect to the bulk of the earth, nobody includes this in the calculation of the orbits.
Some of that momentum bounces back as infrared, part of it interacts and changes energy and momentum of the bulk of the atmosphere ( in complicated manner not yet well understood as Tom says) , but still tiny forces with respect to the bulk atmosphere .
Your error is assuming linearity in the response:
http://en.wikipedia.org/wiki/Statistical_mechanics
You can see in the article that there are no linearities : exponentials in probability functions are involved in the temperature changes so your “will exactly cause a temperature decrease that exactly counteracts ” is not self evident. Care to do the calculations necessary to see how much pressure changes affect temperature changes in this framework, i.e. the photon qm framework? http://star-www.st-and.ac.uk/~mmj/Fluids_notes/fluids_05.pdf
Actually, I had used radiation pressure as an argument that finally all radiation reflected has to vanish into space taking its momentum with it, otherwise from momentum conservation H2O and CO2 should end up in the stratosphere because their numbers are limited, but radiation is continuous and unlimited, and if they are being continuously hit-by/absorbing photons momentum conservation would push them to the stratosphere.

Nasif Nahle says:

Just to give an example, the mean free path length of photons in the CO2 at its current density in the atmosphere is 48 meters.

I checked your paper: http://www.biocab.org/Mean_Free_Path.pdf , and I got confused. Your calculations seem to show that the MFP is 4.8cm, not 48m. I must be missing something obvious, but I can’t spot my oversight. Your help will be appreciated.

I am still a bit puzzled about the CO2 to N2 energy transfer being equal and opposite the CO2 molecule is outnumbered 25 000 to 1 by the other molecules in the atmosphere N2 the largest then O2 and H2O so the chance of the CO2 molecule colliding with a different molecule is 25 000 to 1 the chance of another molecule colliding with a CO2 is 1 in 25 000 but the other molecules will collide with each other thus diluting the energy so I do not think the equal and opposite argument stands.

Tom,
Could you please explain whether nobel gasses emit black body or not??
If they do, could you also speak to whether the IR emitted from the molecular bond is the same as from the blackbody??
I have wondered whether the molecular bond radiation is being conflated with black body radiation which actually shows the TEMPERATURE of particles. This would cause a number of inccorrect assumptions as to where and what is emitting.
That is 15 micron band is also the band of a particular TEMPERATURE emission. How would someone with an IR detector tell whether CO2 was emitting or something at that temperature was emitting? All CO2 can’t be at that same temperature right??