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 – For a another view on the CO2 issue, please see also this guest post by Ferdinand Engelbeen Anthony)
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.
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 . We will use results from statistical thermodynamics and quantum mechanics that have been known for some 100 years or more . More specifically the statement that we will prove is :
“A volume of gas in Local Thermodynamic Equilibrium (LTE) cannot be heated by CO2.”
There are 3 concepts that we will introduce below and that are necessary to the understanding .
- The Local Thermodynamic Equilibrium (LTE)
This concept plays a central part so some words of definition . First what LTE is not . LTE is not Thermodynamic Equilibrium (TE) , it is a much weaker assumption . LTE requires only that the equilibrium exists in some neighborhood of every point . For example the temperature may vary with time and space within a volume so that this volume is not in a Thermodynamic Equilibrium . However if there is an equilibrium within every small subvolume of this volume , we will have LTE .
Intuitively the notion of LTE is linked to the speed with which the particles move and to their density . If the particle stays long enough in a small volume to interact with other particles in this small volume , for example by collisions , then the particle will equilibrate with others . If it doesn’t stay long enough then it can’t equilibrate with others and there is no LTE .
There are 2 reasons why the importance of LTE is paramount .
First is that a temperature cannot be defined for a volume which is not in LTE . That is easy to understand . The temperature is an average energy of a small volume in equilibrium . Since there is no equilibrium in any small volume if we have not LTE , the temperature cannot be defined in this case.
Second is that the energy distribution in a volume in LTE follows known laws and can be computed .
The energy equipartition law
Kinetic energy is present in several forms . A monoatomic gas has only the translational kinetic energy , the well known ½.m.V² . A polyatomic gas can also vibrate and rotate and therefore has in addition to the translational kinetic energy also the vibrational and the rotational kinetic energy . When we want to specify the total kinetic energy of a molecule , we need to account for all 3 forms of it .
Thus the immediate question we ask is : “If we add energy to a molecule , what will it do ? Increase its velocity ? Increase its vibration ? Increase its rotation ? Some mixture of all 3 ?”
The answer is given by the energy equipartition law . It says : “In LTE the energy is shared equally among its different forms .”
As we have seen that the temperature is an average energy ,and that it is defined only under LTE conditions , it is possible to link the average kinetic energy <E> to the temperature . For instance in a monoatomic gas like Helium we have <E>= 3/2.k.T . The factor 3/2 comes because there are 3 translational degrees of freedom (3 space dimensions) and it can be reformulated by saying that the kinetic energy per translational degree of freedom is ½.k.T . From there can be derived ideal gas laws , specific heat capacities and much more . For polyatomic molecules exhibiting vibration and rotation the calculations are more complicated . The important point in this statistical law is that if we add some energy to a great number of molecules , this energy will be shared equally among their translational , rotational and vibrational degrees of freedom .
Quantum mechanical interactions of molecules with infrared radiation
Everything that happens in the interaction between a molecule and the infrared radiation is governed by quantum mechanics . Therefore the processes cannot be understood without at least the basics of the QM theory .
The most important point is that only the vibration and rotation modes of a molecule can interact with the infrared radiation . In addition this interaction will take place only if the molecule presents a non zero dipolar momentum . As a non zero dipolar momentum implies some asymmetry in the distribution of the electrical charges , it is specially important in non symmetric molecules . For instance the nitrogen N-N molecule is symmetrical and has no permanent dipolar momentum .
O=C=O is also symmetrical and has no permanent dipolar momentum . C=O is non symmetrical and has a permanent dipolar momentum . However to interact with IR it is not necessary that the dipolar momentum be permanent . While O=C=O has no permanent dipolar momentum , it has vibrational modes where an asymmetry appears and it is those modes that will absorb and emit IR . Also nitrogen N-N colliding with another molecule will be deformed and acquire a transient dipolar momentum which will allow it to absorb and emit IR .
In the picture left you see the 4 possible vibration modes of CO2 . The first one is symmetrical and therefore displays no dipolar momentum and doesn’t interact with IR . The second and the third look similar and have a dipolar momentum . It is these both that represent the famous 15µ band . The fourth is highly asymmetrical and also has a dipolar momentum .
What does interaction between a vibration mode and IR mean ?
The vibrational energies are quantified , that means that they can only take some discrete values . In the picture above is shown what happens when a molecule meets a photon whose energy (h.ν or ђ.ω) is exactly equal to the difference between 2 energy levels E2-E1 . The molecule absorbs the photon and “jumps up” from E1 to E2 . Of course the opposite process exists too – a molecule in the energy level E2 can “jump down” from E2 to E1 and emit a photon of energy E2-E1 .
But that is not everything that happens . What also happens are collisions and during collisions all following processes are possible .
- Translation-translation interaction . This is your usual billiard ball collision .
- Translation-vibration interaction . Here energy is exchanged between the vibration modes and the translation modes .
- Translation-rotation interaction . Here energy is is exchanged between the rotation modes and the translation modes .
- Rotation-vibration interaction … etc .
In the matter that concerns us here , namely a mixture of CO2 and N2 under infrared radiation only 2 processes are important : translation-translation and translation-vibration . We will therefore neglect all other processes without loosing generality .
The proof of our statement
The translation-translation process (sphere collision) has been well understood since more than 100 years . It can be studied by semi-classical statistical mechanics and the result is that the velocities of molecules (translational kinetic energy) within a volume of gas in equilibrium are distributed according to the Maxwell-Boltzmann distribution . As this distribution is invariant for a constant temperature , there are no net energy transfers and we do not need to further analyze this process .
The 2 processes of interest are the following :
CO2 + γ → CO2* (1)
This reads “a CO2 molecule absorbs an infrared photon γ and goes to a vibrationally excited state CO2*”
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⁺ “. We use a different symbol * and ⁺ for the excited states to differentiate the energy modes – vibrational (*) for CO2 and translational (⁺) for N2 . In other words , there is transfer between vibrational and translational degrees of freedom in the process (2) . This process in non equilibrium conditions is sometimes called thermalization .
The microscopical process (2) is described by time symmetrical equations . All mechanical and electromagnetical interactions are governed by equations invariant under time reversal . This is not true for electroweak interactions but they play no role in the process (2) .
Again in simple words , it means that if the process (2) happens then the time symmetrical process , namely CO2 + N2⁺ → CO2* + N2 , happens too . Indeed this time reversed process where fast (e.g hot) N2 molecules slow down and excite vibrationally CO2 molecules is what makes an N2/CO2 laser work. Therefore the right way to write the process (2) is the following .
CO2* + N2 ↔ CO2 + N2⁺ (3)
Where the use of the double arrow ↔ instad of the simple arrow → is telling us that this process goes in both directions . Now the most important question is “What are the rates of the → and the ← processes ?”
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 .
As we have seen that CO2 cannot transfer energy to N2 through the translation-translation process either , there is no net energy transfer (e.g “heating”) from CO2 to N2 what proves our statement .
This has an interesting corollary for the process (1) , IR absorption by CO2 molecules . We know that in equilibrium the distribution of the vibrational quantum states (e.g how many molecules are in a state with energy Ei) is invariant and depends only on temperature . For example only about 5 % of CO2 molecules are in a vibrationally excited state at room temperatures , 95 % are in the ground state .
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 . 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 . Indeed the right way to write the process (1) is also :
CO2 + γ ↔ CO2* (1)
Where the use of the double arrow shows that the absorption process (→) happens at the same time as the emission process (←) . Because the number of excited molecules in a small volume in LTE must stay constant , follows that both processes emission/absorption must balance . In other words CO2 which absorbs strongly the 15µ IR , will emit strongly almost exactly as much 15 µ radiation as it absorbs . This is independent of the CO2 concentrations and of the intensity of IR radiation .
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 .
Conclusion and caveats
The main point is that every time you hear or read that “CO2 heats the atmosphere” , that “energy is trapped by CO2” , that “energy is stored by green house gases” and similar statements , you may be sure that this source is not to be trusted for information about radiation questions .
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 .
Caveat 2
You will sometimes read or hear that “the CO2 has not the time to emit IR because the relaxation time is much longer than the mean time between collisions .” We know now that this conclusion is clearly wrong but looks like common sense if one accepts the premises which are true . Where is the problem ?
Well as the collisions are dominating , the CO2 will indeed often relax by a collision process . But with the same token it will also often excite by a collision process . And both processes will happen with an equal rate in LTE as we have seen . As for the emission , we are talking typically about 10ⁿ molecules with n of the order of 20 . Even if the average emission time is longer than the time between collisions , there is still a huge number of excited molecules who had not the opportunity to relax collisionally and who will emit . Not surprisingly this is also what experience shows .
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To follow up on Juraj Vs post.
Without doubt, scientifically proven, and indisputable, density of the atmosphere is the primary driver of temperature of the atmosphere.
SO .. can one of you more informed folks than me speculate what impact an increase in CO2 would have on density??
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).
This discussion reminds me of the “CO2 warming violates the 2nd Law” paper by Gerlich :
http://arxiv.org/PS_cache/arxiv/pdf/0707/0707.1161v4.pdf
I like Ed Fix’s comment. While these articles may not prove that CO2 doesn’t lead to warming, what is great is that articles like these encourage critical thinking, rather than the common blind acceptance of political AGW dogma.
@ur momisugly 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.
Steve Goddard
At the North Pole or at least inside the Arctic Circle the mean summer temp is about 2 or 3 deg C as you are well aware, but of course this is at sea level. At the South Pole one is not at sea level but at 3000 to 4000 m altitude (very approx). The atmospheric lapse rate effectively demands that the summer temp is very cold over most of Antartica. But so what? At sea level around the fringe of Antarctica the mean summer temps are, as one would expect, nowhere near as cold.
If you correct for the environmental lapse rate over the interior of Antarctica the mean summer temp is similar to that of summer within the Arctic Circle. I am not saying it is the same given the rather different geography (one polar region is isolated by a very cold Southern Ocean, while the other is ringed by land).
So why is it cold in summer both in the Arctic and the Antarctic. I would venture to suggest that despite high values for summer insolation, the primary reasons are:
1. The angle of incidence, which is low, aiding in the reflection of incoming light.
2. The surface albedo at both poles is such that much of the light that gets to the surface is reflected regardless of the angle of incidence.
So although low greenhouse gas (H2O) concentrations over the Arctic and Antarctic may contribute to low summer surface temperatures these gases are only part of the story.
dp
You are talking to the converted.
I think that H2O provides most of the radiative effects even in deep midwinter Antartica.
Reed Coray says:
August 5, 2010 at 12:00 pm
Reed, the balance equations are just as I wrote them, and you derive the necessary equilibrium temperature from them; there is no need to iterate things. The point being, once the temperature of the “Earth” is such that Iup = 1.25*Iin (in my example), then everything is self-consistent: 80% of that upward flux, which is exactly 0.8*1.25*Iin = Iin, passes through the glass, and goes away; since that exactly matches Iin, no further thermal energy accumulates inside the enclosure. Starting with a “cold” ball, the temperature increases only until that equilibrium temperature is reached, and no further.
The real world is, of course, more complicated; instead of a “glass” you have the greenhouse gases in the atmosphere, but the point is that as long as *some* of the energy they re-radiate goes down, and not up into space, the Earth will have to get warmer than it would be if they were not there, in order for the next flux into space to match the solar input Iin. The other essential point is the spectral asymmetry: namely, that the greenhouse gases are more transparent at visible wavelengths (which is where most of Iin lies) than at infrared, which is where Iup is concentrated.
That’s the big picture, and nothing in Tom’s post has any bearing on it.
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.
In my previous post I did not comment on Tom’s paper because I thought it was an earnest and sincere attempt to explain some of the detailed mechanisms that occur in the atmosphere. However, as many have pointed out, his intitial analysis only applies to LTE which is not realistic, and his development to dynamic systems and his caveats are incomplete.
But I would like to come to his defence because this is the nature of physics. I have studied physics and applied it all my life but I have never been able to use it to directly and completely solve any real life problem. However, by changing the problem to one I could solve (by simplification and limitation) I have gained insights that have allowed me to make and test predictions and create models that are close enough to reality to make them useable. After numerous iterations of this process something close to “good enough” is achieved. This is all I have ever hoped for.
Using such complex but proven models, that have evolved over time, engineers (who in general do not understand the minutae) build the world we see around us. No one uses quantum mechanics to design an aircraft but material science based on QM has provided clues as to what alloys might be worth testing for such a purpose.
Tom has tried to clarify some of those underlying principles but they are only really of academic value. They pertain to systems as defined but are not consistent with the real world. However he has done nothing different from what the climate science community has done except that they have encapsulated these approximations into complex models. The problem is that these models have not been tested and as yet cannot be tested. Rather than attack Tom you should see him as an example of climate scientists of all persuasions who are trying to analyse the behaviour of complex chaotic systems by the application of simplistic relationships studied in a laboratory. The analysis is helpful but there is no certainty in their predictions.
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.
Julio says:
August 5, 2010 at 4:07 pm
Sorry, a typo: I meant the “net flux,” not the “next flux.”
Also, about those balance equations, notice that they work also from the Earth’s point of view: it is radiating at a rate 1.25*Iin, but it is also receiving Iin (directly from the sun) plus the 20% of Iup that is sent back to it by the “greenhouse glass”, which is 0.2*1.25*Iin = 0.25*In. Total, 1.25*Iin.
Jeffid,
Brilliant.
Have a watch going on “global warming” & have noticed the climate alarmists’ new catch phrase is “undeniable” & no longer “settled science.”
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.
The focus is on the gas (CO2) rather than on the radiation budget. The greenhouse gases affect the allwave radiation budget of the Earth’s surface as well as the allwave radiation budget of the atmosphere. For the Earth as a whole and on average, the atmosphere is in radiation deficit, whereas there is a surplus at the surface. Surface-to-atmosphere sensible and latent heat fluxes bring about equilibrium. If there is an increase in CO2, say, the surface-atmosphere budget changes. We get a higher air temperature (i.e. by increased sensible heat flux) and increase in evapotranspiration (i.e. increased latent heat flux).
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.
I don’t follow, here. The net power flowing through a square meter per unit path via advection (is this what you mean by molecular flow?) is specific heat x density x velocity (dot) temperature gradient. I find values of maybe 10 kW per meter squared at a temperature gradient of a degree per hundred meters in a stiff breeze. What is this gross molecular flow of heat?
Very interesting stuff. I’ve only had time to struggle through the article and read the first twenty comments, and can see I have a lot to learn. However I crave to have water vapor included in this sort of discussion. (If it occurs further down in the comments, I will relish it. But I will dare comment before reading all the comments.)
These other gases are rather boring, for they pretty much stay in the gaseous state. Where’s the fun in that? Water vapor, on the other hand, turns from gas to liquid to solid, in the rising tower of a thunder head, and with each change in state there is a vast release of latent energy.
Some of this latent energy is released in the middle of a cloud, even though the relative humidity is 100%, because cloud droplets grow in size.
However the real release of latent energy occurs where the warm air at 100% relative humidity comes in contact with freezing cold air. And where might that be? On the very skin of a cloud, especially the upper skin.
In big thunderstorms, and especially in big hurricanes, this upper skin of clouds, releasing vast amounts of latent energy, is way, way up there, twice as high as Mount Everest. At that altitude there is very little air of any sort, (and especially very little CO2,) between the vast amounts of latent energy being released, and the cold, merciless drain of empty outer space.
In my humble opinion the amount of heat released by water vapor changing state, in a force five hurricane, is so huge that it makes our interesting discussions about the heat involved in CO2, N2 and O2 look a bit like nit-picking.
Tom,
as a physicist, you should know that molecular vibrations are not ‘quantified’. They are quantized. That’s why they call it ‘quantum mechanics’.
All in all, this argument fails for many of the reasons presented already. Most importantly, it’s observationally incorrect. Given that experimental data matters most in physics, I’d retract this whole post if I were you.
IMHO this topic does not belong on your excellent Blog. Too many assumptions and caveats are made without any rational explanation as to how they correspond with the actual atmosphere of the Earth.
For example, if I assume I have a perfectly smooth elephant with negligible mass lots of interesting circus tricks would follow. Sadly, Tom assumes LTE, energy equipartition, time symmetrical equations invariant under time reversal, and then caveats “the dynamics of the Earth-atmosphere system” as well as “relaxation time”.
Don’t get me wrong, I don’t buy into the AGW alarmist story that we are anywhere near a tipping point or even that human CO2 and land use activities are responsible for most of the warming we have experienced in the past 150 years. I think the actual warming is 30% to40% less than the 0.8C claimed by the climate research “team” because they have fudged the data and adjusted for UHI effects improperly. I accept that, after a certain point (about 300 ppmv) CO2 “greenhouse” effects tail off drastically due to saturation.
However, I think it is clear that human activities are responsible for perhaps 10% of the warming. 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. None of this justifies any kind of alarm or any action that would destroy the economy, but it cannot be totally dismissed by the “proof” Tom provides. 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”.
Paul Birch
August 5, 2010 at 4:39 pm
Ok, don’t see where you gave where any of the numbers are coming from but it suffices you seem sure the radiation pressure from added GHG molecules (H2O or CO2), let’s say 10 per million is so infinitesimally small that the lift of the atmosphere in every cubic meter per one meter layer up to say 80 km is so insignificant it can be totally ignored. At one in 10 trillion, I would agree.
Do you mind me asking, how did you come up with the 1 or 1.7 in 10 trillion expansion figure? Very roughly is fine. Was it taking the 390 W/m2 of back radiation in common energy balance charts and calculating from that the upward pressure and therefore the volume expansion?
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.
What I got out of the article was a detailed explanation of the distinction between temperature and heat, with special reference to the nature of radiation in the equation.
Temperature is not heat. I thought that was worth logical discrimination and enjoyed the article.
PS to above post:
I should probably mention that the idea that most of the latent energy in a thermal is released in the “skin” of a cloud is not my own. It was the idea of a commenter in WUWT who was commenting on a comment I made, in the dregs of a posting, when most people likely had moved on to the next fascinating subject. I wish I could remember his name, for his was a really provocative idea.
The idea is that little latent energy can be released in the middle of a cloud, for relative humidity is already at 100%, and it is in some ways hard for water vapor to change to liquid state in such an environment. (Once fog has formed, how can it become more foggy than fog? The answer is “drizzle,” of course, however the latent energy released doesn’t seem enough to power a thermal up to the Stratosphere.)
Therefore the uplift of a thermal could largely be supplied by the “skin” of the thermal. Rather than the air within the thermal lifting the thermal like the air within a hot air balloon, the real uplift is supplied by the skin itself, as if the rubber skin of a hot air balloon was supplying more uplift than the air within the balloon.
This is a really neat idea. It makes you look at clouds in a new way. You entertain the idea a cloud is not “homogenized” uplift. Nor is the latent energy released “homogenized.” Instead the energy is largely released on the “skin,” where it is most likely to radiate out into outer space.
Whoever the fellow was, who shared this idea with me, he deserves, in my humble opinion, more stimulus money than any dweeb fiddling about with the temperatures from 1899, for he challenged me to look at clouds in a new and interesting way.
Of course, he is unlikely to see a cent.
However, in the unlikely event his idea “went viral,” you can bet your bippy Stimulus Money would be spent to shoot his idea down, (as any sort of suggestion that negative feedbacks exist are a threat to “Global Warming,” and therefore a threat to “Cap and Trade.”
But that is a really neat thing about WUWT. Most people don’t post here “for the money.” Rather they are interested in this thing called “Truth.”
Julio says:
August 5, 2010 at 4:07 pm
Reed Coray says:
August 5, 2010 at 12:00 pm
Thank you for your response.
My knowledge of the quantum aspects of radiation is insufficient to either agree or contend with what Tom said. In that light, this response may be off topic. However, your “glass shield” model still confuses me.
I don’t believe it makes a difference to the discussion, but I’m going to assume that the energy source for the enclosed object is radioactivity so deep within the enclosed object that no radioactive energy directly escapes the enclosed object, but rather is converted into heat within the enclosed object. Furthermore, I define the “system” to be comprised of two “subsystems”: (1) the enclosed object including its radioactive internal energy source, and (2) the glass shield. In this “system”, In is the rate of the energy generated by the enclosed object’s internal radioactivity. As I understand your model, the enclosed object thermally radiates energy at the rate 1.25*In, and 80% of this radiated energy passes through the glass shield. For this model, the “system’s” net rate of energy is zero–i.e., In is being generated by radioactivity and In is being radiated to space. However, although energy-rate equilibrium exists for the “system”, it doesn’t exist for both subsystems. For example, consider the “enclosed object subsystem”. The rate of energy input to this subsystem is In, while the rate of energy leaving this subsystem is 1.25*In. Where does the extra 0.25**In rate of energy come from? It doesn’t come from radioactivity. If it comes from the glass shield, then the energy input to the enclosed object is no long In, and I argue we must now “iterate” because we have changed the rate of energy input to the enclosed object. If it comes from thermal energy contained within the enclosed object, the temperature of the enclosed object will decrease.
Bottom line, I don’t see how you can say that without iteration “everything is self-consistent”. The “enclosed object subsystem’s” net rate of energy is not self-consistent.