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.
davidmhoffer says:
Fine…We know bounds on the temperature. Actually, the 288 K is the experimentally-measured average temperature, so we know that pretty well. We know that in the absence of a greenhouse effect, the average temperature could not possibly be greater than ~255 K. Hence, the greenhouse effect raises the average temperature by at least 33 K.
However, you are simply wrong about the “wildly inaccurate” part. As I have explained, for the current Earth, the temperature is uniform enough that in fact the difference between computing T and the fourth root of T^4 is not that large. [I was able to get a difference of 6 K only by considering a temperature distribution that is clearly broader than the actual temperature distribution….probably broader by a factor of 3 or so.]
An Earth without the greenhouse effect is a rather hypothetical situation. However, if such an Earth still had a substantial atmosphere, it is likely that the temperature distribution would still not be nearly as broad as under the assumption that the local temperature is obtained by radiative balance with the LOCAL (in space and time) insolation.
Tim Folkerts says:
Yes, this is a better way to say it. It will also depend on two other things:
(1) the amount of bulk mixing that is occurring; hence, the gases will be more well-mixed in the troposphere where there is a lot of mixing than in the stratosphere where there is much less.
(2) the existence of large sources and sinks and the lifetimes of the substances. Longer lifetimes favor more uniform mixing because there is a longer time for the substance to become well-mixed. Similarly, having a smaller flux from sources and sinks favors more uniform mixing for the same reason.
Richard M says:
Actually, I don’t think it really does. What is most important is the concentration in the troposphere and it looks like all of those substances are pretty well-mixed in the troposphere. Furthermore, CO2…having a very long lifetime…would tend to be more well-mixed than the substances that they study there.
Richard M says:
It is also worth noting that Figure 1 for the case of CH_4 actually contradicts your point. Note that CH_4 is lighter than the primary atmospheric constituents of N_2 and O_2 and hence one would expect that, on the basis of your hypothesis, the mixing ratio should INCREASE at higher altitudes. It actually decreases. I presume that is because the lack of well-mixedness in the stratosphere is related to the mechanisms by which CH_4 is converted to other substances (including CO2, by the way) and not anything having to do with molecular mass…in fact, in spite of its lower molecular mass.
One other quick point to follow up on Joel’s recent comments.
Richard’s link shows that O3 (a heavy gas) is enhanced in the upper atmosphere, while CH4 (a light gas) is diminished in the upper atmosphere. These results are the OPPOSITE of what would be expected based simply on mass and gravity. Clearly there is much more involved than ‘heavy gases settling to the bottom’.
Stephen Wilde says:
At this point, I am beginning to see why when some of my colleagues ask students to provide an explanation for something, they often append a statement that says “using correct physics principles”.
So, let me put it another way: Using correct physics principles, explain how the Earth and its atmosphere could possibly absorb 240 W/m^2 with the surface emitting 390 W/m^2 of radiation, none of which is absorbed by the atmosphere, and hence all of which escapes to space.
“Whilst in kinetic form it is transferred between molecules by convection and conduction involving molecular collisions.”
i.e it HAS been absorbed by the atmosphere but as a result of conduction and not downward radiation from GHGs.
Tim Folkerts @ur momisugly January 8, 8:50 pm
Thanks for your interest Tim.
~~~~~~~~~~~~~
Joel Shore @ur momisugly January 9, 10:29 am
In response to your little obfuscations:
Yet
Again
Wearisome
Nnonsense
~~~~~~~~~~~~
shawnhet @ur momisugly January 9, 9:45 am
Sorry about my little rant. I get frustrated too sometimes
Stephen Wilde says:
There is something very basic that you are not understanding: You seem to keep trying to answer the question of how the surface can get heated up a certain amount by considering how energy could get transferred to the surface from the atmosphere.
However, that is not the issue. The issue is that an Earth surface that is at a temperature where it is emitting 390 W/m^2 is emitting back out into space far more energy than the Earth+atmosphere are receiving from the sun. As a result, the Earth + atmosphere is emitting far more energy than it is receiving and the system as a whole will rapidly cool.
The ONLY remedy to this energy balance problem for the entire earth + atmosphere system is to say that not all of the power emitted by the surface actually escapes to space. That is the ONLY way to solve the problem. You can’t solve it by explaining how the surface is receiving enough energy because the issue is not with how much energy the surface is receiving but how much energy the entire Earth+atmosphere system are receiving.
Richard M says:
January 10, 2012 at 5:56 am
Once the air pressure gets low enough the heavier CO2 cannot be kept aloft, hence adding more CO2 will not significantly increase the average height of gas.
Correct, the layer of the atmosphere where gases are not segregated by their molecular mass is the homosphere, above that layer is termed the heterosphere where gases are segregated by their molecular mass. For the Earth that transition occurs at 80-100km altitude, so the troposphere is entirely in the homosphere. Consequently when discussing the GHE the change in gaseous composition with altitude is not relevant except for non ‘permanent’ gases such as H2O or O3.
“is to say that not all of the power emitted by the surface actually escapes to space”
I am saying that.
The atmosphere holds onto enough energy to raise the system temperature to a level whereby the energy leaving matches the energy coming in.
The denser the atmosphere the more radiative energy is converted to kinetic energy (heat) in the atmosphere and delayed in its exit from the atmosphere until a new higher equilibrium temperature is reached and then energy in again equals energy out.
Due to the delay caused by conduction replacing radiation in the course of energy passing out through the atmosphere the surface needs to increase to a temperature at which it radiates 390 at the surface in order to get 240 out through the atmosphere.
It is exactly the same principle that you invoke for GHGs but in fact the causation is not GHGs. It is the density of the atmosphere slowing things down and heating things up and not the GHGs (or not much anyway).
Tim Folkerts says:
January 10, 2012 at 9:54 am
One other quick point to follow up on Joel’s recent comments.
Richard’s link shows that O3 (a heavy gas) is enhanced in the upper atmosphere,
The reason for this is O3 is both created and destroyed in the upper atmosphere. It has nothing to do with mass.
Yes, the chemical reactions also make a difference. But, in the case of CO2 there is nothing that I’m aware of, of any magnitude, and it should form a distribution like the other heavier gases.
Stephen Wilde says:
Well, that is impossible if the atmosphere is transparent to the radiation emitted by the surface.
Except the principle does not work unless the atmosphere is able to absorb the radiation emitted by the surface. Do you understand what the concept of an atmosphere transparent to radiation emitted by a surface means?
Joel,
The atmosphere heats up from conduction of kinetic energy from molecule to molecule.
Your obsessive belief that everything is radiative is your downfall.
Between energy coming in as solar shortwave and energy going out as longwave it is the non radiative processes that dominate and the denser the atmosphere the longer the energy is in kinetic non radiative form so that the transmission through the system is slowed down, heat builds up in the system and surface temperatures rise.
Are you really a scientist ?
“The reason for this is O3 is both created and destroyed in the upper atmosphere. It has nothing to do with mass. ”
I’m grateful for that comment because it was bothering me.
On the face of it the warming of the stratosphere could have been an obstacle to the possibility that upward radiation of CO2 (accelerating energy loss to space) approximately offsets the downward radiation of CO2 (decelerating energy loss to space).
It is the creation/destruction balance that makes a difference as regards Ozone in the stratosphere and not absolute quantiities.
WHERE IS THE PROMISED “NEXT WEEK” N&K “REPLY PAPER”?
OK, Dec 30 + a week = Jan 06.
The above is Ned Nikolov’s last posting on this thread, and his last posting on the other WUWT thread is dated January 5, 2012 at 8:37 am.
So far, proponents of the N&K theory have proposed a wide variety of interpretations, including:
1) A more dense atmosphere yields a higher pressure. Compared to a planet with no atmosphere, or a less dense atmosphere, a higher pressure atmosphere evens out the temperatures around the planet, which makes the average temperature higher than it would be otherwise. This effect works with or without GHGs. This appears to be a valid scientific observation to me, but it does not appear to be earth shaking and I cannot understand how it could explain their other claims.
2) Higher density (more pressure) causes CO2 spectral lines to broaden, which makes it a more effective GHG. Presumably this effect also applies to other GHGs as well. In a less dense atmosphere, such as Mars, there are spaces between the spectral lines so some significant portion of the UW LWIR from the Surface towards Space gets a free pass out, reducing the radiant energy that powers the GHE. Widened spectral lines will block some of that free pass. This appears to be a valid scientific observation to me, and I expect it to be featured in the N&K “reply paper” but I cannot understand how it could explain their other claims.
3) Mean temperatures should be computed by averaging T^4 and then taking the fourth root of the result. I agree that is mathematically and scientifically correct, but I do not see how that could amount to more than a few degrees on a planet like the Earth.
4) The reputed average temperature of the Moon, 250K, may be quite a bit too high. It seems to me that this could indeed be true, but not to the extent of 100K, and it all depends upon how one measures temperatures on a body with no atmosphere. I do not know how this will come out.
5) There is some kind of “enhancement” when photons pass through a more dense atmosphere, and/or some other effects of gravity that somehow “enhance” temperatures, but do not really create more energy than supplied by the Sun to the Earth/Atmosphere system. This effect (whatever it may be) is independent of GHGs. After reading all the comments on this thread, I still have no idea what this “enhancement” effect might be, and I look forward to an explanation “in English” that I can comprehend, and, of course, a scientifically valid exposition that some of the more astute climate scientists can assure me rings true (or at least possible :^).
Meanwhile, this thread is approaching 1000 Comments, a new record for my topics. THANKS ALL!
-Ira
Stephen Wilde:
Are you really that incapable of understanding what I am saying? I am not talking about how the atmosphere or how the surface warms up….It can warm up by whatever magical processes you invent for it to warm up as far as I am concerned.
To repeat my statement once again: The Earth + atmosphere cannot be emitting 390 W/m^2 back out into space when it is only absorbing 240 W/m^2 from the sun. If it does this, it will rapidly cool down. You have failed to explain how the 390 W/m^2 emitted AS RADIATION by the surface can be prevented from going back out into space without anything in the atmosphere to absorb some of this radiation and hence prevent its transmission to space.
Ira,
It probably doesn’t matter anyway…My prediction is that when said reply does come out, it will not address the substantive critiques on the original work. It will probably focus on sidelights that are not really important (or even well-defined) like what the average temperature of the moon is. By doing so, it will avoid the obvious, which is that:
(1) There is no known way to satisfy conservation of energy for the Earth + atmosphere global energy balance without invoking the radiative greenhouse effect.
(2) N&Z’s way of putting convection into the simple radiative model of the greenhouse effect that they started with is fatally flawed because it assumes that convection will drive the system to an isothermal temperature profile with height when it actually drives it only to the adiabatic lapse rate profile. This error is what makes the greenhouse effect virtually disappear in that model and anybody in the field could have told them this beforehand if they had bothered to ask.
(3) Their other arguments as to why the radiative greenhouse effect is unimportant are similarly flawed.
(4) Their empirical fit involves four free parameters plus additional freedom in how they chose to define the T_sb of the planets. And, (closely related to your point #1) as they have chosen to define T_sb, their surface temperature enhancement doesn’t even primarily reflect the greenhouse effect; it mainly reflects the fact higher surface pressures lead to a more uniform temperature distribution and a more uniform temperature distribution leads to a higher average temperature without changing the total power emitted by the surface. For only 1 of the 8 celestial bodies that they fit to does the radiative greenhouse effect constitute the majority of their so-called “surface temperature enhancement”; and it is only likely to be a significant contributor (say, greater than ~10%) to the “surface temperature enhancement” in 2 more. Hence, their many-parameter fit is not even fitting to what they claim to be fitting to.
Ira says:
You list this as one of the things that has been said by the proponents of the theory, which I won’t disagree with. However, the irony of it is that said proponents fail to realize that they are arguing for EXACTLY THE OPPOSITE of what N&Z are doing. I.e., the traditional way of computing T_sb is indeed to take the average insolation over the surface (which is proportional to T^4), divide by sigma, and take the 4th root.
However, N&Z have actually done the opposite: They make an approximation for the local temperature that is only correct in the limit of an airless planet and then average this temperature…not T^4…over the surface of the Earth.
This illustrates how many of the defenders of N&Z actually have no conception of what N&Z are actually doing!
Stephen Wilde says:
January 10, 2012 at 3:32 pm
“The reason for this is O3 is both created and destroyed in the upper atmosphere. It has nothing to do with mass. ”
I’m grateful for that comment because it was bothering me.>>>
Stephen,
Not only is it created and destroyed, the mechanism is self regulating.
Ozone is destroyed at the top of the oxygen layer (mostly) and created at the bottom. The UV frequencies that do the creating are absorbed to a certain extent by the ozone layer itself. As the ozone layer thickens, ozone creating UV gets increasingly absorbed, and the amount of ozone being produced per unit of time drops. If the ozone layer thins to below itz equilibrium thickness, the ozone production rate must rise because less ozone creating UV is filtered out.
Hence, the ozone layer is self regulating. It cannot increase beyond a certain point before production falls, causing it to thin, and it can’t thin beyond a certain point because production rises, causing it to thicken.
The only real variable is in the mix of UV frequencies being emitted from the sun. If UV frequencies that create ozone increase, then the equilibrium thickness increases (for example).
Joel Shore;
Frankly Joel, you really have missed the whole point. Your example is meaningless because you’ve picked unreal data points to get to your 6 degrees differential. You’ve missed the point I and others have been making in regard to the range of temperatures versus blackbody versus the range of observed temperatures. They are NOT the same thing!
Question: What is the blackbody equilibrium temperature of a body absorbing 0 w/m2?
Answer: ZERO.
The point is that ZERO is the blackbody equilibrium temperature of half the planet 12 hours per day.
ZERO!
The blackbody temperature of earth during the day ranges from ZERO to nearly 400K!
THAT is the range, not 255 to 288.
The “temperature” of the earth at any given time in any given place is NOT the blackbody temperature NOR is it the blackbody temperature plus GHE.
It is the blackbody temperature + GHE + LATENT HEAT
If there was no latent heat in the earth’s crust and oceans, the temperature would in fact (in the tropics) have no choice but to fluctuate between ZERO and 400K + GHE. The fact that the earth DOES retain latent heat and acts like a giant heat sink results in earth temperatures fluctuating between a much narrower range. But if you wish to rely upon blackbody and GHE ONLT, then the range is:
Zero to (400 + GHE)
And that gives you a somewhat large distribution than your cherry picked 6 degrees.
Stephen Wilde;
I said:
Ozone is destroyed at the top of the oxygen layer (mostly)>>>>
Of course I meant at the top of the ozone layer…
Too little sleep, too much wine…
Joel Shore says:
January 10, 2012 at 4:33 pm
You have failed to explain how the 390 W/m^2 emitted AS RADIATION by the surface can be prevented from going back out into space without anything in the atmosphere to absorb some of this radiation and hence prevent its transmission to space.
>>>
It’s called mass extinction coefficient Joel, and it dims light by absorption regardless of frequency, ruling out and ghg-only effects, and is only affected by the mass of the gases that the radiation passes through. Check a good land-based astronomy or radio astronomy book on it’s explicit calculations and effects. You will also hear it termed attenuation.
Just remember that radiation leaving the surface is isotropic in nature, and by pure geometry, that radiation has more passing generally horizontally than generally upward. Play that into the extinction equations as you integrate it in relation to the LW radation. Your factor of 240/390 sounds pretty close.
You have spent far too much time in your mind living within half-baked models.
So far, proponents of the N&K theory have proposed a wide variety of interpretations, including:
“1) A more dense atmosphere yields a higher pressure….
More atmospheric mass obviously yields higher pressure. Air pressure has to to with mass of all
the gas molecules. Density has nothing to do with pressure. It’s gravity and mass of gas or mass of liquid.
“2) Higher density (more pressure) causes CO2 spectral lines to broaden.”
I heard this said, but doesn’t make any sense. CO2 which solid or liquid or gas should have same absorption lines and and therefore should same emission lines. Gravity can bend light?? Orbital speed will redshift??? Don’t see how any of the helps, or makes any difference.
“4) The reputed average temperature of the Moon, 250K, may be quite a bit too high. It seems to me that this could indeed be true, but not to the extent of 100K, and it all depends upon how one measures temperatures on a body with no atmosphere. I do not know how this will come out.”
Yeah don’t even know earth’s average temperature, don’t why it matters.
The only reason it’s important is because some think there is a relationship between average temperature and blackbody.
“5) There is some kind of “enhancement” when photons pass through a more dense atmosphere, and/or some other effects of gravity that somehow “enhance” temperatures, but do not really create more energy than supplied by the Sun to the Earth/Atmosphere system. This effect (whatever it may be) is independent of GHGs. After reading all the comments on this thread, I still have no idea what this “enhancement” effect might be, and I look forward to an explanation “in English” that I can comprehend, and, of course, a scientifically valid exposition that some of the more astute climate scientists can assure me rings true (or at least possible :^).”
I didn’t think the enhancement had to with going thru atmosphere, but rather had to do with interaction of atmospheric gas and surface temperature.
But would like to hear what “enhancement” was to do photons and atmosphere- only thing I am aware of is the atmosphere reduces the amount solar energy passing thru any atmosphere- absorption and refraction/reflection.
Wayne suggests that: “It’s called mass extinction coefficient Joel, and it dims light by absorption regardless of frequency, ruling out and ghg-only effects, and is only affected by the mass of the gases that the radiation passes through. Check a good land-based astronomy or radio astronomy book on it’s explicit calculations and effects. You will also hear it termed attenuation.”
So give us some actual number here, Wayne. There are always additional details that might be important, but it is equally important to know when NOT to worry about a correction.
For example, my knowledge suggest that attenuation of x-rays by the atmosphere is quite extreme (hence there are no x-ray telescopes on the ground). There are good reasons to expect this (compton scattering, ionization, and others). Visible light is also scattered by “clear” atmosphere. The most common and familiar effect is Raleigh scattering which makes the sky blue, but this only a few percent of the visible light after traveling all the way thru the atmosphere.
IR would suffer even less Raleigh scattering — like 10^-4 as much. Some people have hard time believing that 20% absorption by CO2 could be important; now were are talking ppm of IR getting absorbed as they try to escape.
Those are my estimates. Please provide your own estimates from your favorite land-based astronomy or radio astronomy book and show that the results for 4-20 um IR are significantly large enough to be important in this discussion.
One can sidestep a lot of the conceptual problems some here are having if one regards the density/mass/pressure of the atmosphere as shifting the balance (within the flow of energy through the system) from fast radiation towards slower conduction giving a rise
in equilibrium temperature as a consequence.
After all, no atmosphere at all means an immediate turnaround of energy i.e.
radiation straight in and straight out pretty much instantly.
As soon as one then adds an atmosphere capable of CONDUCTION which includes non GHGs then the
conduction takes away from the efficiency of the radiation process by
slowing energy dissipation down which is what then leads to the higher
equilibrium temperature. The denser the atmosphere the more conduction takes
place before the radiative energy can be released to space and the higher
the equilibrium temperature rises.The density of the atmosphere at the surface is controlled by gravity because a stronger gravitational pull reduces volume.
So, radiative processes are not in control because they are subject to
interference from density and the consequent increase in conduction relative to radiation.
Convection and the water cycle then act to try to reduce the slowing effect
on energy dissipation of more conduction but can never get back to the
efficiency of raw, in/out, radiation.
In order to maintain the outward radiation of 240 Wm2 and thereby match the incoming of 240Wm2 the surface temperature needs to rise in order to overcome the retention of energy by the atmosphere caused by conduction to the air.
At Earth’s atmospheric pressure the surface temperature rises to a point where the surface needs to radiate 390 Wm2 in order to get 240Wm2 out into space past the resistance of the atmosphere.That atmosphere absorbs via conduction the balance of 150Wm2.
That all happens as a result of atmospheric mass. Nothing to do with the thermal properties of GHGs so that then provides the baseline adiabatic lapse rate for our particular planet.
If one then adds some GHGs then they will have an effect but only above the surface and so far no one has suggested any evidence that the 50% of their emissions directed downwards to decelerate the energy flow through the system fails to be offset by the 50% that goes upward to accelerate energy flow out of the system.
Or that increased convection and evaporation fail to eliminate the contribution from GHGs.
So we have a clear and obvious greenhouse effect from atmospheric mass but no proven similar net effect from GHGs.