Guest Post by Ira Glickstein
The Unified Theory of Climate post is exciting and could shake the world of Climate Science to its roots. I would love it if the conventional understanding of the Atmospheric “Greenhouse” Effect (GHE) presented by the Official Climate Team could be overturned, and that would be the case if the theory of Ned Nikolov and Karl Zeller, both PhDs, turns out to be scientifically correct.
Sadly, it seems to me they have made some basic mistakes that, among other faults, confuse cause and effect. I appreciate that WUWT is open to new ideas, and I support the decision to publish this theory, along with both positive and negative comments by readers.
Correlation does not prove causation. For example, the more policemen directing traffic, the worse the jam is. Yes, when the police and tow trucks first respond to an accident they may slow the traffic down a bit until the disabled automobiles are removed. However, there is no doubt the original cause of the jam was the accident, and the reason police presence is generally proportional to the severity of the jam level is that more or fewer are ordered to respond. Thus, Accident >>CAUSES>> Traffic Jam >>CAUSES>> Police is the correct interpretation.
Al Gore made a similar error when, in his infamous movie An Inconvenient Truth, he made a big deal about the undoubted corrrelation in the Ice Core record between CO2 levels and Temperature without mentioning the equally apparent fact that Temperatures increase and decrease hundreds of years before CO2 levels follow suit.
While it is true that rising CO2 levels do have a positive feedback that contributes to slightly increased Temperatures, the primary direction of causation is Temperature >>CAUSES>> CO2. The proof is in the fact that, in each Glacial cycle, Temperatures begin their rapid decline precisely when CO2 levels are at their highest, and rapid Temperature increase is initiated exactly when CO2 levels are their lowest. Thus, Something Else >>CAUSES>> Temperature>>CAUSES>> CO2. Further proof may be had by placing an open can of carbonated beverage in the refigerator and another on the table, and noting that the “fizz” (CO2) outgasses more rapidly from the can at room temperature.
Moving on to Nikolov, the claim appears to be that the pressure of the Atmosphere is the main cause of temperature changes on Earth. The basic claim is PRESSURE >>CAUSES>>TEMPERATURE.
PV = nRT
Given a gas in a container, the above formula allows us to calculate the effect of changes to the following variables: Pressure (P), Volume (V), Temperature (T, in Kelvins), and Number of molecules (n). (R is a constant.)
The figure shows two cases involving a sealed, non-insulated container, with a Volume, V, of air:
(A) Store that container of air in the ambient cool Temperature Tr of a refrigerator. Then, increase the Number n of molecules in the container by pumping in more air. the Pressure (P) within the container will increase. Due to the work done to compress the air in the fixed volume container, the Temperature within the container will also increase from (Tr) to some higher value. But, please note, when we stop increasing n, both P and T in the container will stabilize. Then, as the container, warmed by the work we did compressing the air, radiates, conducts, and convects that heat to the cool interior of the refrigerator, the Temperature slowly decreases back to the original Tr.
(B) We take a similar container from the cool refrigerator at Temperature Tr and place it on a kitchen chair, where the ambient Temperature Tk is higher. The container is warmed by radiation, conduction and convection and the Temperature rises asymptotically towards Tk. The Pressure P rises slowly and stabilizes at some higher level. Please note the pressure remains high forever so long as the temperature remains elevated.
In case (A) Pressure >>CAUSES A TEMPORARY>> increase in Temperature.
In case (B) Temperature >>CAUSES A PERMANENT>> increase in Pressure.
I do not believe any reader will disagree with this highly simplified thought experiment. Of course, the Nikolov theory is far more complex, but, I believe it amounts to confusing the cause, namely radiation from the Sun and Downwelling Long-Wave Infrared (LW DWIR) from the so-called “Greenhouse” gases (GHG) in the Atmosphere with the effect, Atmospheric pressure.
Some Red Flags in the Unified Theory
1) According to Nikolov, our Atmosphere
“… boosts Earth’s surface temperature not by 18K—33K as currently assumed, but by 133K!”
If, as Nikolov claims, the Atmosphere boosts the surface temperature by 133K, then, absent the Atmosphere the Earth would be 288K – 133K = 155K. This is contradicted by the fact that the Moon, which has no Atmosphere and is at the same distance from the Sun as our Earth, has an average temperature of about 250K. Yes, the albedo of the Moon is 0.12 and that of the Earth is 0.3, but that difference would make the Moon only about 8K cooler than an Atmosphere-free Earth, not 95K cooler! Impossible!
2) In the following quote from Nikolov, NTE is “Atmospheric Near-Surface Thermal Enhancement” and SPGB is a “Standard Planetary Gray Body”
NTE should not be confused with an actual energy, however, since it only defines the relative (fractional) increase of a planet’s surface temperature above that of a SPGB. Pressure by itself is not a source of energy! Instead, it enhances (amplifies) the energy supplied by an external source such as the Sun through density-dependent rates of molecular collision. This relative enhancement only manifests as an actual energy in the presence of external heating. [Emphasis added]
This, it seems to me, is an admission that the source of energy for their “Atmospheric Near-Surface Thermal Enhancement” process comes from the Sun, and, therefore, their “Enhancement” is as they admit, not “actual energy”. I would add the energy that would otherwise be lost to space (DW LWIR) to the energy from the Sun, eliminating any need for the “Thermal Enhancement” provided by Atmospheric pressure.
3) As we know when investigating financial misconduct, follow the money. Well, in Climate Science we follow the Energy. We know from actual measurements (see my Visualizing the “Greenhouse” Effect – Emission-Spectra) the radiative energy and spectra of Upwelling Long-Wave Infrared (UW LWIR), from the Surface to the so-called “greenhouse” gases (GHG) in the Atmosphere, and the Downwelling (DW LWIR) from those gases back to the Surface.
The only heed Nikolov seems to give to GHG and those measured radiative energies is that they are insufficient to raise the temperature of the Surface by 133K.
… our atmosphere boosts Earth’s surface temperature not by 18K—33K as currently assumed, but by 133K! This raises the question: Can a handful of trace gases which amount to less than 0.5% of atmospheric mass trap enough radiant heat to cause such a huge thermal enhancement at the surface? Thermodynamics tells us that this not possible.
Of course not! Which is why the conventional explanation of the GHE is that the GHE raises the temperature by only about 33K (or perhaps a bit less -or more- but only a bit and definitely not 100K!).
4) Nikolov notes that, based on “interplanetary data in Table 1” (Mercury, Venus, Earth, Moon, Mars, Europe, Titan, Triton):
… we discovered that NTE was strongly related to total surface pressure through a nearly perfect regression fit…
Of course, one would expect planets and moons in our Solar system to have some similarities.
“… the atmosphere does not act as a ‘blanket’ reducing the surface infrared cooling to space as maintained by the current GH theory, but is in and of itself a source of extra energy through pressure. This makes the GH effect a thermodynamic phenomenon, not a radiative one as presently assumed!
I just cannot square this assertion with the clear measurements of UW and DW LWIR, and the fact that the wavelengths involved are exactly those of water vapor, carbon dioxide, and other GHGs.
Equation (7) allows us to derive a simple yet robust formula for predicting a planet’s mean surface temperature as a function of only two variables – TOA solar irradiance and mean atmospheric surface pressure,…”
Yes, TOA solar irradiance would be expected to be important in predicting mean surface temperature, but mean atmospheric surface pressure, it seems to me, would more likely be a result than a cause of temperature. But, I could be wrong.
Conclusion
I, as much as anyone else here at WUWT, would love to see the Official Climate Team put in its proper place. I think climate (CO2) sensitivity is less than the IPCC 2ºC to 4.5ºC, and most likely below 1ºC. The Nikolov Unified Climate Theory goes in the direction of reducing climate sensitivity, apparently even making it negative, but, much as I would like to accept it, I remain unconvinced. Nevertheless, I congratulate Nikolov and Zeller for having the courage and tenacity to put this theory forward. Perhaps it will trigger some other alternative theory that will be more successful.
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UPDATE: This thread is closed – see the newest one “A matter of some Gravity” where the discussion continues.
Re my post immedately above, that relates to an earlier thread.
Joel and Tim thank you for your response. However it was Joel that was pointing out emissity in the transfer equations. I went back to my heat transfer book and using the Hottel charts I get an emissivity for a CO2,H2O mixture at 288K and 1 ATM of about .02. So again I ask what emissivity do you use for a water vapor and carbon dioxide mix at 288K and 1 atm.
I apologize for not using your quote but my new tablet doesnot cut and paste well.
Bob Fernley-Jones says:
Bob: You are arguing against a strawman that you have created. Nobody is bashing cross disciplinary cooperation. But cross disciplinary cooperation does not mean that one comes into a field without having understood even the most basic elements of it, proposes a “theory” that one claims overturns nearly all the current thinking in the field, and whose “theory” is manifestly based on silly misconceptions and doesn’t even obey the most basic laws of physics. That is what N&Z has done.
It is a sad fact that not everybody in the world gets to be Galileo, Copernicus, and Einstein. To be Copernicus and Einstein, you actually have to be naturally quite brilliant, you have to put in more work to actually first understand the field you are trying to overturn the paradigm in, and you have to have some truly remarkable and original insight.
davidmhoffer says:
Dave,
If you think a little bit about it, you will realize that the two statements that I have highlighted above contradict each other. You are right in the first paragraph but wrong in the second. This basically makes the conclusions of your whole post incorrect.
You are also continuing to be fascinated by the idea of computing the average temperature from the local insolation, an approximation that is unbelievably atrocious for any planet like the Earth with a significant atmosphere. And, you continue to abhor computing the average temperature for a uniform distribution (or equivalently, computing it based on averaging T^4 over the surface and then taking the 4th root) even though this approximation is pretty damn good for the Earth with its current temperature distribution.
However, if you want to believe that the effect that needs to be explained is larger than 33 K, then I won’t continue to argue with you about that point. However, what I will say is that you will be able to explain a lot of it away by just messing around with the temperature distribution but you can play with the temperature distribution from now til doomsday and you will never explain away the last 33 K because that comes from the fundamental fact that the Earth’s surface is emitting ~390 W/m^2 while the Earth & its atmosphere absorb only 240 W/m^2 from the sun…and the only explanation for that is the fact that there are elements of the atmosphere that absorb some of the terrestrial radiation.
P.S. – Dave, I realized one way in which you might think the two statements you made don’t contradict each other: Somehow you might have the impression that the temperature distribution in space has to obey the inequality we have highlighted, but you can get around it by having fluctuations in time. That is incorrect. Whether the distribution changes in space or time is irrelevant from the mathematical point-of-view. It will still be true that, given the average power emitted, you will have a constraint on the average temperature.
mkelly:
I have only mentioned emissivity in the context of the surface of the Earth, for which it is sensible to define such a thing because the Earth’s surface is solid or liquid. The arguments that we are discussing here do not explicitly need to consider the details of the radiative properties of the greenhouse gases in the atmosphere. It is simply sufficient to point out that the only way to get energy conservation is to have an atmosphere that can absorb terrestrial radiation.
What we are actually saying is that the empirically-observed situation that the Earth’s surface emits 390 W/m^2 and the Earth+atmosphere only absorb 240 W/m^2 is evidence that there must be enough greenhouse elements in the atmosphere to account for the discrepancy. The fact that the experimentally observed spectrum seen from space shows emission of only 240 W/m^2 and the tell-tale signs of absorptions at precisely the wavelengths that we expect given the constituents of our atmosphere is then further empirical evidence that there is not some other “magic” going on (like to heretofore unidentified source of energy).
When scientists want to actually do QUANTITATIVE calculations of the greenhouse effect, I don’t think there are really any shortcuts they can take. They have to do “line-by-line” radiative transfer calculations. They can’t just plug things into the Stefan-Boltzmann Law.
The simple models of the radiative greenhouse effect like the one that N&Z start out talking about do model the atmosphere as a layer having a certain emissivity…and they are useful for qualitative understanding, but they are not useful for quantitative calculations.
Bart says:
Yes…but it also doesn’t mean that we can’t sometimes ignore friction, say, when we are on an air-hockey table. Or, the fact that Newton’s Laws are incorrect in the light of relativity does not mean that we have to use relativistic equations to deal with motion in our everday lives.
Our point is that you can always identify non-idealities in the real world. After all, all of our discussions here on both sides have neglected the gravitational force on the Earth due to Alpha Centuri, not to mention that from the black hole that is (might be?) at the center of our galaxy. Does that mean that everything here is incorrect?
You have identified some implicit assumption that is made everytime any scientist or engineer applies the standard equations used for radiative transfer (at least for solids and liquids). Now, we are simply asking you to present some sort of evidence that the assumption is so poor that it makes a significant enough difference to matter. Tim has made the point that even given the highly non-equilibrium environment of the surface of the sun, the approximation seems to work pretty well in describing the emission from the sun.
Bart – You also still haven’t answered my basic question:
Joel Shore says:
January 7, 2012 at 5:54 am
[Richard M says:
In addition, the GHGs are mostly heavier gases. Gravity will make it tougher and tougher to find sufficient GHGs to absorb additional radiation. It will take a larger addition of GHGs to push more of them into higher elevations. In addition, since the areal surface is also expanding it takes more and more GHGs to produce the same effect. This works in concert with the saturation effect as well.]
There are various confusions present here. You are neglecting entropy: Gases will mix by diffusion and much faster by convection. So, in fact, theory predict and experimental data confirm, that CO2 is generally well-mixed in the atmosphere except at near-surface levels close to significant sources and sinks. Outside of those regions, deviations from uniformity in ppm are only a few percent at most.
I think I need to go back to this claim by Joel. I think it helps provide the answer as to why there is a maximum GHE. What Joel didn’t consider is why the gases are well mixed. Clearly, if we put all the gases into a container without any energy source the heavier gases would fall to the bottom first. It is energy that keeps gases well mixed.
This is almost an exact analogy to my rocket ship example. You can only get a rocket ship so high in the atmosphere before the continual effort of lifting the weight of the rocket overcomes the energy in the fuel. You have to eliminate that weight (via stages) to get more height. This same factor applies to the GHE. It is the energy of the atmosphere that allows it to be mixed. That energy takes the form of convection and conduction to lift keep the heavier particles like CO2 aloft.
The key though is what is happening when convection occurs? Energy is being used and heat is being transported to higher altitudes where is can easily escape to space. Just as in the rocket ship example there is a limit to this energy and at some point it won’t be possible to lift any significant amount of CO2 any higher. I suspect this limit is based on the mass of the atmosphere, the strength of the gravitation field and the amount of energy available. This is EXACTLY what the K/Z correlation has found and it should be relatively easy to model.
Ergo, there is a maximum greenhouse effect and chances are the Earth has already achieved it.
BTW, as I stated earlier, having a max GHE means we shouldn’t see correlations between temperature and CO2 concentrations. And, that is exactly the case. What we should see is correlations between temperature and the amount of solar energy reaching the surface. Bingo! This is probably why we see so many examples of temperatures changing with solar variation. It would also explain why albedo changes would have a major impact on climate. It also fits the idea that the atmosphere was more dense when dinosaurs and flying reptiles existed on Earth. Everything fits so beautifully.
Do we have any people out there that can build a simple model of the activity of CO2 in a gravitational field? Or, does one already exist? This could be fairly simple as we don’t need to really model the Earth. Just throw in CO2 with a bunch of N2, apply some gravity and see what happens. Vary the concentrations, the size of the gravitational field and the energy input and we should be able to build a curve of gravity’s impact on CO2’s GHE.
“Just throw in CO2 with a bunch of N2, apply some gravity and see what happens. Vary the concentrations, the size of the gravitational field and the energy input and we should be able to build a curve of gravity’s impact on CO2′s GHE.”
Gravity has its own GHE and it is fixed by mass plus solar input.The study of other planets provides the comparisons you suggest. On that basis N & Z are confirmed to be correct but no doubt some will try to say that the data for the other planets is incorrect. That is just a desperate rearguard action. Time will prove such objectors to be wrong.
GHGs try to alter the gravity induced lapse rate but fail.
Instead, the surface pressure distribution shifts a fraction to eliminate the effects of GHGs.That shift is a climate effect but as nothing compared to natural variability from sun and oceans.
Joel Shore,
You are making the mistake of comparing a uniform distribution in one case to a non uniform distribution in another case. One can only arrive at 33K as the total GHE provided that one assumes a uniform distribution of both T and P. If such existed, then 33K would be the GHE and this in turn would be the MINIMUM GHE that could exist for a planet of “average” temperature 288K and “average” insolation of 240 w/m2. We can surmise than ANY variance in T or P away from uniformity can have no other effect than to dramatically increase GHE. 33K is fictitious, as is 255K and 288K.
The T of earth and the P of earth must satisfy both conservation of energy and SB Law.
That being the case, in order to calculate the “T” of earth from observed T taken over both space and time, T must be calculated by raising each data point to the power of 4, averaging, and then taking the 4th root. Any other method of calculating (for lack of a better term) the effective T of earth would result in a value that would not balance P in SB Law.
If you are in agreement with the above, then the minimum effective T of earth would be calculated from a uniform distribution of T. The higher the variance in T, the higher the effective T that would be calculated, and the higher it would be in comparison to T arrived at through a strict average.
Per your point, if we begin with P instead of T, the maximum T that can be derived from SB Law and an average P of 240 w/m2 is in fact 255K.
If you’ve agreed so far, we’ve now reached the moment of truth. The Aha! moment.
Just as the effective T of earth calculated correctly yields a value higher than the average T, the converse is true of T calculated from P! Since the relationship is between P and T^4, one CANNOT average P and then calculate T! We MUST take the observed value of P as a function of time over the course of both day and year, and over latitude, and solve for T^4th over the curve. We can then integrate to arrive at an average of T^4 and take the 4th root of that to arrive at an effective T that would balance P in the SB Law equation. The result for any distribution of P that is not uniform must be less than 255K.
So now put it all together.
Our average surface temperature of earth is reported as 288K derived from an average of observed T. The effective T is higher.
The value of 255K is calculated from 240 w/m2 is derived from the average of P. The calculation of T derived from (lack of better term again) the effective P is lower.
You’ve not only agreed to this, you have stipulated that 255 is the maximum, all non uniform distributions of P must therefore be lower!
Which is why it is impossible to attribute ANY amount of warming to GHG’s by calculating 288 – 255 = 33. That number represents the minimum GHE, not the effective GHE! Given a uniform distribution of P and T, that is the GHE. As variance in both T and P increase, the only possible result is an increase in GHE as expressed in degrees T. All 288 – 255 gives us is the minimum value which would occur only in the case of a uniform distribution of both P and T. All other values must increase as uniformity decreases.
Given the variability of P (from zero to 1,000 w/m2 daily) and the variability of T (from -80C to +40C on a global basis at all times) there can be no other conclusion than the total GHE is not the minimum ideal case of 33K, but a much larger number, on the order of 150K. The values of 33K, 255K and 288K do NOT satisfy both conservation of energy and SB Law EXCEPT in the case of complete uniformity, and are hence useless for deriving anything meaningful in terms of GHE, and the consequences of increasing or decreasing GHG’s.
Until we agree on the above, there is little value in arguing how much of the GHE is due to what processes. We can only have that discussion if we agree as to what the total GHE actually is in the first place. Given that 33K is unsupportable except in the case of a completely uniform T across earth in both time and space accompanied by a uniform P across time and space, I think you must agree that total GHE is not only larger than 33K, is is MUCH larger than 33K.
The very simple math exercize I’ve shown upthread shows pretty clearly that 150K is reasonable.
If you are in agreement with that, we can move onto a discussion as to how much of the 150K is due to GHG’s and how much is due to other factors.
Bart says:
January 7, 2012 at 11:50 am
Say what? I never heard of that description of a blackbody before. I’d need a citation for that claim, Bart. Why should it only exchange energy through radiation?
Also, you still don’t seem to get that I am using the “blackbody temperature” as a measurement, rather than a description of the system. I say that the Jelbring/Nabokov process cannot push a planet to a higher temperature than it’s blackbody temperature.
w.
davidmhoffer: I pretty much agree with what you have said – the radiative greenhouse effect increases the surface temperature by at least 33 K. Depending on how one defines it, it could be more. Probably the most fundamental way to say what the radiative greenhouse effect does is to avoid quoting temperatures altogether and just say that it increases the temperature to a point where the surface emits ~390 W/m^2 whereas in its absence the surface could not emit more than ~240 W/m^2. And, then it follows that an Earth without this effect but otherwise the same (e.g., same albedo) would necessarily have an average temperature of 255 K or less.
No “Ah ha!” moment is needed from me on this as I already understood this and expressed it all in a comment here on Dec. 31, as I linked to above.
However, I think that you are making much too big a deal out of this, at least for current Earth-like temperature distributions. The fact is that the distribution of temperatures on the Earth is such that this is a small effect. It may be a little bit larger an effect for an Earth without greenhouse gases, since this would allow somewhat larger temperature swings, but still likely not that large as long as there is a significant atmosphere of any kind.
Actually, Dave, I also think it is somewhat strange that you think that you have to explain all this to me as I have been talking about it for days…The one you have to explain it to is Ned Nikolov, who seems to be under the illusion that the temperature distribution can’t affect the average temperature that he computes: http://wattsupwiththat.com/2011/12/29/unified-theory-of-climate/#comment-855376
Ira Glickstein says:
To be honest, I haven’t really looked into the data closely enough to have a strong opinion, but from what I have seen, I will use this as a further illustration of the points I am trying to make. According to this website http://www.asi.org/adb/m/03/05/average-temperatures.html ,
So, the answer seems to be that the average temperature that you get for the moon depends on details, such as if you measure right at the surface or several centimeters below the surface. Why is this the case? It is so because the moon is an airless body and the temperature right at the surface varies widely depending on whether it is day or night. However, several cm below the surface, the temperature is more uniform.
So, what might we conclude from this? I think there are a couple of different options:
(1) Average temperature is not even a well-defined concept for airless bodies that are subject to wide temperature variations. The value you get depends on details such as exactly how deep below the surface you choose to make your measurements.
(2) Maybe we can define an “average temperature” in a way that is more robust, e.g., would give about the same value if you compute it at the surface or several cm below the surface. In fact, I think we can: I think if we defined the average to be averaging T^4 and taking the 4th root then we would find such an average to be more robust to the issue of exactly how far below the surface, we measured it.
Who knows…although as I have pointed out to you, pressure broadening is the main explanation for their data showing “surface temperature enhancement”. I think the main explanation is that the way they have chosen to define T_sb means that their “surface temperature enhancement” is mainly due to the atmosphere evening out the temperature distribution. The radiative greenhouse effect is only the dominant contribution to the “surface temperature enhancement” as they define it on one of the 8 celestial bodies that they looked at.
Bart;
A blackbody exchanges energy through radiation only.>>>
Willis;
Say what? I never heard of that description of a blackbody before. I’d need a citation for that claim, Bart. Why should it only exchange energy through radiation?>>>
Willis, I see your “Say what?” and raise you a “huh? are you kidding?”
SB Law is the calculation of how much energy a blackbody emitts through radiation at a given temperature. Bart’s statement is correct by definition of SB Law. That doesn’t mean that a blackbody can ONLY exchange energy through radiation, but the definition of blackbody as it applies to SB Law is definitive in that regard in the absence of all other factors (which was the purpose of defining a blackbody for SB Law calcs in the first place).
Willis;
Also, you still don’t seem to get that I am using the “blackbody temperature” as a measurement, rather than a description of the system. I say that the Jelbring/Nabokov process cannot push a planet to a higher temperature than it’s blackbody temperature.>>>
Please see my last comment upthread. You are of course correct in your assertion. The problem is that your assertion is valid for one use case, and one use case only, which is a uniform distribution of P and a uniform distribution of T. That is the ONLY case in which the “average” insolation of 240 w/m2 and the “average” T of 288K yield a GHE of 33K. All other cases yield a GHE of greater than 33K, with the magnitude of the GHE increasing as variability of P and T increase despite their “average” values remaining constant.
All arguments based on the numbers of 33K, 255K and 288K are valid ONLY for the case of a 100% uniform distribution of T and P.
Such does not exist and never has existed in the history of the earth.
“Say what? I never heard of that description of a blackbody before. I’d need a citation for that claim, Bart. Why should it only exchange energy through radiation?”
A black body is in space. Space can only transfer energy via radiation.
The highest temperature of a black body is directly related to sun’s temperature and distance from it.
Take the energy radiated at sun surface and spread that over a sphere with diameter of earth’s orbit and that is blackbody temperature at earth distance. Or said differently, that is the temperature of the sun at that distance.
The radiant energy of the sun at earth distance will not cause any object exceed that temperature, it will not flow energy or heat to it.
The hottest the sun’s radiation can heat a object at earth distance is around the temperature of the lunar surface- about 123 C [400 K].
One can of course magnify the sun’s energy and or use various other means and get higher temperatures from the Sun’s energy.
Stephen Wilde says:
One of the problems in discussions like this is that so much effort is expended on correcting the misconceptions and incorrect notions that people have that very little time gets devoted to the correct physics explanations. So, I think rather than continuing to explain where you are wrong, I’ll simply describe how it actually works:
(1) First, let’s imagine we could “turn off” convection. In such a case, the radiative greenhouse effect would cause the “effective radiating level” in the atmosphere (where the temperature is 255 K) to be at about 5km and there would be some lapse rate down to the surface. I am not sure what that lapse rate would be, but based on estimates I have heard for the greenhouse effect in the absence of convection, let’s say that it is 12 C per km. That means that the surface temperature would be 60 C above 255 K, or 315 K. [ (12 C per km) X (5 km) = 60 C]
(2) Now, let’s imagine increasing the amount of greenhouse gases so that the level at which the radiation can escape to space without being absorbed again (the “effective radiating level”) increases from 5km to 6km in altitude. Assuming that the lapse rate remains 12 C per km, that means that the surface temperature would be 72 C above 255 K, or 327 K. Note that the temperature has risen by 12 C due to the increase in greenhouse gases.
(3) Now, let’s repeat the above but add in convection. What convection does is drive the lapse rate back down to the (appropriate) adiabatic lapse rate. It does not drive the lapse rate lower than this because for lower lapse rates, the atmosphere is stable and convection is suppressed. It appears that a reasonable estimate of the average lapse rate established in the atmosphere (taking into account dry and saturated lapse rates) is about 6.5 C per km. That means that with our initial level of greenhouse gases (i.e., the effective radiating level at 5km), the surface temperature would be 32.5 C above 255 K, or 287.5 K. Notice that the effect of convection has reduced the greenhouse effect: It used to raise the temperature above 255 K by 60 C but now only raises it above 255 K by 32.5 C.
(4) Now, let’s imagine again increasing the amount of greenhouse gases so that the effective radiating level rises to an altitude of 6km. To a first approximation, convection will keep the lapse rate unchanged at 6.5 C per km. That means that the surface temperature would now be 39 C above 255 K, or 294 C. Note that the addition of greenhouse gases has still caused an increase in temperature but the increase in temperature is only 6.5 C now instead of the 12 C that would have occurred if convection were not present.
That, in a nutshell, is how the greenhouse effect works. This picture has the advantage over other notions in that it has both empirical evidence and calculations using empirically-well-verified physics equations to back it up. It also does not violate fundamental physical constraints like conservation of energy.
“By removing the redistribution effect of GHG’s, we must see an INCREASE in temperature differentials which in turn means an INCREASE in energy moved about via conduction and convection.”
oh, so now somebody notices!!!
it’s like fundamental to refrigeration – any increase in the heat carrying capacity of the working fluid results in increased cooling efficiency.
of course, nobody uses gases that don’t change phase for serious cooling – but plain dry gas will still cool your car engine or cpu. denser gases work better – for carrying heat away in a circulating system. denser gases do not insulate at all.
radiative processes may be involved at the source and sink ends, but within the flux – get real.
when my coffee is too hot, i don’t hold a black book over top of it to remove the heat by sucking out the radiation. jeez.
and omg- you don’t even wanna know what the thermal, volumetric and pressure fx are when a liter of water gas abruptly changes into a mere teaspoon of falling liquid. the co2 clown won’t even bring a smile any more…
Joel Shore;
Probably the most fundamental way to say what the radiative greenhouse effect does is to avoid quoting temperatures altogether and just say that it increases the temperature to a point where the surface emits ~390 W/m^2
No “Ah ha!” moment is needed from me on this as I already understood this and expressed it all in a comment here on Dec. 31, as I linked to above.>>>>
Joel, look at what you wrote.
Where does the 390 w/m2 come from?
It comes from converting 288K to w/m2 via SB Law.
Except that you just agreed, in fact admonished me for explaining to you, that the 288K number is a pure fiction except for one tiny use case that is physically impossible to exist! You’ve come full circle, first agreeing that 288K is meaingless, and then proceeding to define conditions at earth surface based exclusively on 288K!
Sorry Joel but your response still fails to acknowledge the existence of a gravity induced GHE.
Until you do so AND attribute the correct scale to it in relation to the radiative GHE your comments are worthless.
The gravitational GHE provides a fixed baseline lapse rate for a planet with an atmosphere of given mass with a given solar input.
The portion added by the radiative GHE is small, limited to the atmosphere and leads to a negative system response via increased convection, conduction evaporation and condensation.
There is a tiny rise in the height of the tropopause and a tiny increase in surface temperature but they count for nothing compared to natural variability.
davidmhoffer says:
The part of my post you are missing is this, David:
If you want to argue that 390 W/m^2 might really be 395 W/m^2 or 400 W/m^2, then I won’t disagree. In fact, the updated version of Trenberth and Kiehl now says 396 W/m^2 and I think part of the upward adjustment is due to the fact that they have now tried to take into account the non-uniform temperature distribution issue. But, 390 W/m^2 is a nice round number and a good conservative estimate, so I continue to use it for the sake of such discussions. (In the back of my mind is also the fact that the Earth is not exactly a blackbody and this means its will emit a bit less than you get from applying the Stefan-Boltzmann Equation with emissivity 1. It is somewhat convenient that the “not exactly a blackbody” and “not exactly a uniform temperature distribution” effect act in the opposite direction and hence tend to partially cancel each other out.)
Stephen Wilde says:
Oh yeah, and I also forgot to acknowledge the magical energy fairies. My bad.
I addressed the following to Willis several days ago, but he does not seem to be interested. Any other takers?