Joel Shore: The Radiative Greenhouse Effect

Posted: February 21, 2012 by tallbloke in atmosphere, climate, Energy, general circulation

My thanks to Joel Shore, who has produced a position statement we can give consideration to, and formulate a response. Here’s a prime opportunity not only for those who wish to discuss the role and limitation of ‘back radiation’ in the atmosphere, but also for those who want to tackle the thorny issue of the treatment of the Earth’s surface as a ‘black body’. Comments containing snark will simply disappear in their entirety, so be warned.

The following is the correct science, agreed to be so by essentially all of the scientists actively working in the field including “skeptics” like Richard Lindzen and Roy Spencer and backed by a wealth of empirical evidence and correct physics principles:

(1) The lapse rate: The lapse rate in the troposphere is large because the troposphere is strongly heated from below (by the Earth’s surface, absorbing radiation from the sun and back-radiation from the atmosphere) and cooled from above (by the emission of radiation by greenhouse gases and clouds in the atmosphere). In fact, the average lapse rate would be steeper than the observed rate of temperature decreasing by ~6.5 C per km if convection did not occur. However, convection does occur because lapse rates steeper than the appropriate (dry or moist) adiabatic lapse rate are unstable to convection. Hence, convection occurs and drives the lapse rate down to the appropriate adiabatic lapse rate. Note that the dry adiabatic lapse rate is given by -g/C_p where g is the gravitational acceleration and C_p is the specific heat at constant pressure. Since the end result of the above considerations is an average lapse rate close to a compromise between the dry and moist adiabatic lapse rates, the lapse rates is indeed determined in large part by gravity.

(2) The radiative greenhouse effect: Contrary to what some people seem to believe, the lapse rate in the troposphere alone does not determine the surface temperature. This is because you have the equation for a line of the form y = m*x + b where x = height, y = temperature, and m = lapse rate but b is not determined. One way b can be determined is by specifying one particular (x,y) value on the line. The physical constraint that does this is the constraint of radiative balance between the Earth and the rest of the universe, which says that at the effective radiating level, the average temperature must be 255 K (modulo the issues of average of T^4 vs average of T). For the Earth in its current state, the effective radiating level is at about 5 km. This value together with the average lapse rate of ~6.5 C per km then allows us to determine the average temperature of the surface by extrapolation: 255 K + (5 km)*(6.5 C / km) = 287.5 K.

(3) A few consequences are worth noting here: One is that if the effective radiating level were at the surface, as would necessarily be true for an atmosphere that is transparent to terrestrial radiation (i.e., no greenhouse gases or clouds), then the temperature at the surface would have to be 255K. (Or, more precisely, once you take the distinction between averaging T and averaging T^4 into account, the temperature at the surface could be no greater than 255 K). A second is that if convection were not present and the lapse rate were thus greater, then the temperature at the surface would be higher; hence, the effect of convection is to reduce the magnitude of the radiative greenhouse effect. (As I recall, the natural greenhouse effect would be approximately twice as large, 60 C or so instead of ~33 C, if there were no convection.) A third is that if the lapse rate were zero, say because one mistakenly put convection into a model of the greenhouse effect so that it drove the lapse rate to zero, one would get that the temperature of the surface is 255 K + (5 km)*(0 C / km) = 255 K, i.e., there would be no greenhouse effect. The fact that convection only drives the lapse rate down as far as the (appropriate) adiabatic lapse rate is thus vital to the existence of the radiative greenhouse effect.

(3) Changes in the concentrations of greenhouse gases: If you change the concentration of greenhouse gases, then (to first order), you do not change the average lapse rate but what you do change is the height of the effective radiating level. For example, if the effective radiating level were to rise to 6 km, then the surface temperature would now be 255 K + (6 km)*(6.5 C / km) = 294 K, or 6.5 K higher than before. [To a better approximation, the average lapse rate actually decreases slightly because the moist adiabatic lapse rate is a decreasing function of the surface temperature, so the temperature increase would be a little less than this. This is referred to as “the lapse rate feedback”, a negative feedback included in all of the climate models.]

That is a basic summary of the radiative greenhouse effect. If you want to attack this well-confirmed scientific picture, that is what you should be attacking.

1. I have posted on my own blog a reply to Roy Spencer, which also applies to Joel Shore:

Incompetent Skeptics III: Roy Spencer

The greenhouse effect, of increasing atmospheric temperature with increasing atmospheric carbon dioxide, does not exist. That is the empirical fact of two detailed planetary atmospheres. The radiative transfer theory, which implies that effect, is factually disproved (see the link to my Venus/Earth analysis at the above site). Mr. Shore is deluded, myopically focused upon his theoretical dogma and unheeding of the definitive fact. The portion of the Sun’s radiation that can and does warm the atmosphere is entirely different than the portion that can be and partially is reflected, and his value of 255K for the radiating temperature of the Earth-plus-atmosphere system (which uses “incident minus reflected” radiation intensity in the Stefan-Boltzmann formula, not “incident”) is wrong. My Venus/Earth comparison simply demonstrates there is no greenhouse effect–as I have defined it and as is being foisted upon the public by the IPCC and all of our suborned institutions–and there is no albedo effect, upon the warming of the atmosphere (the Venus/Earth temperature ratio, over the range of Earth tropospheric pressures, is entirely and precisely explained by the ratio of the two planets’ distances from the Sun). There are no competent climate scientists, have been none for 20 years.

2. Stephen Wilde says:

i) Seems to be taking the ‘surface’ for S-B purposes as a point within the atmosphere.
I’d like to hear a justification for that.

ii) Seems to be assuming that backradiation emanates from the entire atmospheric column and not just from the molecules near the surface that have been heated by pressure and insolation as per the Gas Laws.

iii) The Gas Laws apply to all atmospheres whether comprised of GHGs or not so Joel needs to explain how the Gas Laws can cease to apply so as to produce a zero Greenhouse effect on a planet with an atmosphere. I think the truth is that he can postulate a zero RADIATIVE greenhouse effect but that leaves the separate pressure and insolation induced greenhouse effect pursuant to the Gas Laws. Furthermore the latter accounts for observations without the need for a radiative effect anyway so how does Joel justify proposing an alternative to the Gas Laws when they are apparently sufficient ?

iv) Raising the effective radiative height only alters the environmental lapse rate which is highly variable from multiple causes. Changing the environmental lapse rate does not necessarily result in a warmer surface globally. It can simply represent a change in energy flow through the system. To get the warmer surface globally you have to change the dry adiabatic lapse rate but you cannot do that without also changing pressure at the surface or insolation.

3. One place to start, perhaps:

*The physical constraint that does this is the constraint of radiative balance between the Earth and the rest of the universe, which says that at the effective radiating level, the average temperature -must be 255 K*

This can’t be assumed unless you accept that earth’s effective temperature should be that of a perfect S&B black-body. N&Z demonstrate that this is not a wise assumption.

4. Hans says:

Dear Joel and all,

For sure there exists a “Greenhouse Effect” based on observational evidence. It is certain that the average surface temperature of earth is higher than the average temperature of earth seen from space. This situation exist to a much higher degree on Venus and the gigant planets dure to thicker atmospheres.

The reason why your reasoning above and conventional mainstream climatologists are wrong is that they have ignored to explore all possible physical processes that can create the observed GE on Earth, Venus, Titan. The surface temperatures on Jupiter, Saturn, Neptune and Uranus has not been observed yet but the temperature lapse rate in the upper troposphere of all the mentioned planets are close to -g/Cp which is the dry adiabatic temperature lapse rate.

The existence of an (approximate) dry adiabatic temperature lapse rate is equivalent with an even distribution of total energy per mass unit in these planetary atmospheres (below about 0.2 bar) which seem to be the approximate border of the upper troposphere in all the mentioned planets.

The reason why the planetary atmospheres are seeking to achieve the dry adiabatic temperature lapse rate is found in the second law of thermodynamics applied to a gas system involving gravity. It has to be emphasized that the second law of thermodynamics primarily deals with energy and not temperature. This energy dissipation process has not been discovered by mainstream climatologists for unknown reasons. It means that several available physical processes are acting to produce the dry adiabatic temperature lapse rate (or wet pseudoadiabatic lapse rate if condensation processes occur). Solar irradiation over land surfaces always produce DALR from the surface and upwards. It is best developed during late afternoons. At dawn the surface starts cooling and a nigh temperate inversion develops at the surface. Radiation processes and mixing processes cooperate to create the the DALR. Other physical processes are disturbing this to happen such as radiative IR emission from earth surface, subsidence in the troposphere and tidal motion of the atmosphere and ocean water.

You are saying:
“That is a basic summary of the radiative greenhouse effect. If you want to attack this well-confirmed scientific picture, that is what you should be attacking.”
The problem you face is that you consider the observed GE being caused primarily by radiative processes which is a reductionistic treatment of the problem which is the reason why I don´t approach each one of your points 1-4 above. As you yourself claim, your reasoning is restricted to the “radiative greenhosue effect”. That effect is very small considering the impact of carbon dioxide but has to be taken into account relating to the impact of water vapour.

Hans Jelbring

5. tallbloke says:

Hans: yes, I was interested to see that Joel cheerfully announces that:

“the lapse rates is indeed determined in large part by gravity.”

But doesn’t seem to realise the extent to which this marginalises the role of radiation.
How exactly does he think gravity determines the lapse rate if not via pressure and density?

6. tallbloke says:

Would we not expect there to be significant back radiation from the underside of clouds, even if we can’t measure it well from ground level?

7. Joel Shore says:

Stephen Wilde says: “i) Seems to be taking the ‘surface’ for S-B purposes as a point within the atmosphere. I’d like to hear a justification for that.”

Obviously, this is the simple picture that emerges from more complex numerical calculations. The actual calculations use the equations fro radiative transfer in a medium (see http://en.wikipedia.org/wiki/Radiative_transfer )

“ii) Seems to be assuming that backradiation emanates from the entire atmospheric column and not just from the molecules near the surface that have been heated by pressure and insolation as per the Gas Law.

Yes…all molecules that are capable of emitting radiation will radiate although the density and the temperature will determine how much radiation a certain volume emits.

“iii) The Gas Laws apply to all atmospheres whether comprised of GHGs or not so Joel needs to explain how the Gas Laws can cease to apply so as to produce a zero Greenhouse effect on a planet with an atmosphere.”

They don’t cease to apply. For a system without a definite volume, the ideal gas law can be written with 3 variables, temperature, pressure, and number density. The pressure does not uniquely determine the temperature. That is why nobody has produced a derivation of the empirical fitting form of N&Z from the ideal gas law.

“iv) Raising the effective radiative height only alters the environmental lapse rate which is highly variable from multiple causes.”

No…The average environmental lapse rate is determined by the fact that lapse rates greater than the appropriate adiabatic lapse rate are unstable to convection. Hence, it is essentially an average of the the appropriate adiabatic rate over the Earth’s surface. (Although there will be some regions in space and time where the environmental lapse rate is less than the adiabatic lapse rate, i.e., there is an inversion.)

8. Joel Shore says:

tallbloke says: “But doesn’t seem to realise the extent to which this marginalises the role of radiation. How exactly does he think gravity determines the lapse rate if not via pressure and density?”

I am not sure where the misconception arose that the scientific understanding of the greenhouse effect proposes that increasing the concentration of greenhouse gases increases the lapse rate. It does not increase the lapse rate. It increases the surface temperature because it raises the effective radiating level, and hence you have to extrapolate down further from this level (where the temperature is 255 K) to get the temperature at the surface, as I showed by example in my second point (3). 😉

9. Stephen Wilde says:

rog,

I’m not sure that the back radiation from clouds is significant.

If they are high up most if not all downward diverted radiation gets scattered before it hits the ground.

If they are low down they seem to work by suppressing evaporation from ocean surface or soil moisture and limiting convection rather than radiating downward. Someone once said that each cloud floats along on its own bubble of humidity.

Given the dominance of the Gas Laws in setting surface temperature and the patchy nature of Earth’s clouds I’m inclined to think that they are not significant in global terms as regards downward radiation.

Their effect gets lost in the whole Gas Law / ATE equation otherwise we wouldn’t get that comparability between Earth and Venus at similar atmospheric pressures subject to an adjustment for distance from the sun. The Venus atmosphere is full of cloud.

They are just a consequence rather than a cause as I think N & Z said at one point.

10. Hans says:

tallbloke says:
February 21, 2012 at 9:59 pm

“But (Joel/HJ) doesn’t seem to realise the extent to which this marginalises the role of radiation.
How exactly does he think gravity determines the lapse rate if not via pressure and density?”

I don´t know how Joel thinks but as a general rule I have always claimed that “mental inertia is the strongest form of inertia that exists.”

Joel is as he himself claims in no way alone in his way of thinking (claiming being right because of consensus does not belong to scientific methods). It will be interesting to get Joel´s comments on this thread using arguments based on scientific reasoning.

[Reply] I’ll repost those parts of his comments which fit that template.
🙂

11. Hans says:

Stephen Wilde says:
February 21, 2012 at 10:34 pm

“I’m not sure that the back radiation from clouds is significant.”

I can assure you that a cloud cover in midwinter in Stockholm area (59 latitude north) means it is about 5-10C warmer than if the sky is clear. At the same time I am absolutely sure there exists nothing such as +300 W/m^2 back radiation in the real world.

12. Mydogsgotnonose says:

Not being a climatologist or climate scientist, but having a very good grounding in thermodynamics and physics, also being a lateral thinker, I have a rather different viewpoint to most people.The first thing that climate science should unlearn is the concept of direct thermalisation of absorbed IR energy to the N2 and O2 majority molecules. it can’t happen because that energy is quantised, so can only be transferred to another GHG molecule.

Also the argument that in the ~1 ms that it takes for the excited molecule to re-emit that photon, it has about 1000 collisions to transfer the energy is also bunkum because the principle of Local Thermodynamic Equilibrium means that another excited molecule [~5% of CO2 at room temperature] will emit the same energy photon in a random direction, restoring equilibrium. This failure to understand that molecules have no history appears to be another basic fault of climate science.

So, I believe there can be no direct radiative greenhouse effect! However, Tyndall and the modern PET bottle experiments apparently prove it exists. How? Well, both experiments are effectively constant volume so much of the higher temperature of the CO2 is because it has expanded and the expansion is constrained. Unscrew the cap, the temperature rise is much lower and the real heating is probably at the walls of the container! In my view, this is a serious and very basic mistake by climate science.

There a pseudo GHG effect. Thinking this out is taking some time because it appears to be new science and the concept of thermodynamic temperature for random IR scattering is obscure. However, the scattered IR will thermalise at second phases that are cooler than the source temperature of most of the radiated IR that arrives: that could be the Earth surface temperature. If the IR impacts a warmer surface, it cannot thermalise because to do so would be a brwach of the 2nd law of Thermodynamics.

The Prevost Exchange Energy coming to the earth’s surface will vary considerably depending on the closeness of clouds. Hence when you measure the apparent emissivity, it will vary considerably. I can’t see that any of this basic thinking has been done in climate science. None of the models can predict climate and it’ll take a lot of work to do so: I’d guess a decade.

13. Ulric Lyons says:

“A few consequences are worth noting here: One is that if the effective radiating level were at the surface, as would necessarily be true for an atmosphere that is transparent to terrestrial radiation (i.e., no greenhouse gases or clouds), then the temperature at the surface would have to be 255K.”

255K, the average soil temperature of equatorial Lunar soil. It has though a 140K monthly range, so the max is around 325K, similar to the surface temp on a very hot day in a dry desert on Earth.
The upper values are very similar. The question is, would that same dry desert cool down to 255-70K (185K) if it had c.14 days of darkness like the Moon does, and if it had no lateral atmospheric circulation to provide warmer air from elsewhere ? such as we find in the Antarctic.
Also, in relation to atmospheric convection, is it taken into consideration that water vapour has a much lower density than dry air?

14. TB and Joel
Thanks both of you for publishing this here, thus allowing Joel’s argument to be stated clearlyt and concentrated in one place rather than being scattered and draining everyone’s energies.

15. tallbloke says:

Stephen Wilde says: “i) Seems to be taking the ‘surface’ for S-B purposes as a point within the atmosphere. I’d like to hear a justification for that.”

Obviously, this is the simple picture that emerges from more complex numerical calculations. The actual calculations use the equations fro radiative transfer in a medium (see http://en.wikipedia.org/wiki/Radiative_transfer )

“ii) Seems to be assuming that backradiation emanates from the entire atmospheric column and not just from the molecules near the surface that have been heated by pressure and insolation as per the Gas Law.

Yes…all molecules that are capable of emitting radiation will radiate although the density and the temperature will determine how much radiation a certain volume emits.

“iii) The Gas Laws apply to all atmospheres whether comprised of GHGs or not so Joel needs to explain how the Gas Laws can cease to apply so as to produce a zero Greenhouse effect on a planet with an atmosphere.”

They don’t cease to apply. For a system without a definite volume, the ideal gas law can be written with 3 variables, temperature, pressure, and number density. The pressure does not uniquely determine the temperature. That is why nobody has produced a derivation of the empirical fitting form of N&Z from the ideal gas law.

“iv) Raising the effective radiative height only alters the environmental lapse rate which is highly variable from multiple causes.”

No…The average environmental lapse rate is determined by the fact that lapse rates greater than the appropriate adiabatic lapse rate are unstable to convection. Hence, it is essentially an average of the the appropriate adiabatic rate over the Earth’s surface. (Although there will be some regions in space and time where the environmental lapse rate is less than the adiabatic lapse rate, i.e., there is an inversion.)

16. tallbloke says:

And his reply to me. Looks like he’s still fidgeting around the bit, but getting closer… 🙂

tallbloke says: “But doesn’t seem to realise the extent to which this marginalises the role of radiation. How exactly does he think gravity determines the lapse rate if not via pressure and density?”

I am not sure where the misconception arose that the scientific understanding of the greenhouse effect proposes that increasing the concentration of greenhouse gases increases the lapse rate. It does not increase the lapse rate. It increases the surface temperature because it raises the effective radiating level, and hence you have to extrapolate down further from this level (where the temperature is 255 K) to get the temperature at the surface, as I showed by example in my second point (3). 😉

17. SergeiMK says:

Stephen Wilde says: February 21, 2012 at 10:34 pm
“I’m not sure that the back radiation from clouds is significant.”
========
Steven, How do you explain the measurements I have posted before
Southern Great Plains:
From this referenced document the LWIR MEASURED is 300+w/m^2 during the day (note that the peak frequency TSI is filtered from these measurements (The AERI-ER measures downward infrared radiance from 3.3 to 25 um (400 to 3000 cm- 1) with a spectral resolution of 0.482 cm ^-1)
From this referenced document the LWIR MEASURED is 200+w/m^2 during the night

In the arctic
From this referenced document the LWIR MEASURED is 140w/m^2 during the night and day

Click to access Marty2003_IPASRCII_JGR.pdf

Please note this is measured IR near the surface, coming from all directions above the level of the receivers. It DOES NOT measure the heat of O2/N2/etc.

This radiation is continuous night and day depending on the latitude. but I assume not longitude.

There is an experiment shown here that possibly shows some easily measured GHE.
http://climateandstuff.blogspot.com/2011/11/confirmation-of-green-house-effect.html

18. Mydogsgotnonose says:

SergeMK: the experiment does not prove any GHG warming because the glass of the vacuum flask may cause the heating as IR is scattererd by the CO2.

The only way you can prove the effect would be to use a rock salt or similar container.

19. Michael Hart says:

Mydogsgotnonose,
Are there potential ‘second order’ effects in the thermalization of IR as you explain it happening [or not happening] ? I use the term ‘second order’ to loosely mean bimolecular interactions between GHG molecules. More specifically, radiative and collisional interactions between CO2 and H2O molecules in the gas phase where one of them has absorbed a quanta of IR. [Not necessarily CO2 at the ~15um wavelength, though this is obviously of interest]. Would it be necessary to have strict spectral overlap for these to occur?

The next question might be whether such considerations have any implications for the surfaces of liquid water/ice at cloud surfaces. But that’s probably another kettle of fish.

Small quibble: [[[“iii) The Gas Laws apply to all atmospheres whether comprised of GHGs or not so Joel needs to explain how the Gas Laws can cease to apply so as to produce a zero Greenhouse effect on a planet with an atmosphere.”

They don’t cease to apply. For a system without a definite volume, the ideal gas law can be written with 3 variables, temperature, pressure, and number density. The pressure does not uniquely determine the temperature. That is why nobody has produced a derivation of the empirical fitting form of N&Z from the ideal gas law.]]]

Actually for a given atmospheric mass (number density), surface pressure WILL be fixed, leaving temperature and volume as variable. I believe this is the basis of N&Z’s claims, although your point is that this is, as yet, unproven and we’re all aware of that.

No snark intended, but my impression is that predictions regarding escalating temperatures, sea level, drought, crop failure, etc. haven’t really been borne out based on the models that rely on radiative “forcings”. That doesn’t mean you are wrong (and I’m in no position to argue whether you are or not), but it certainly implies that at least some people have an agenda that the radiative model (conveniently, for them) seems to support.

I guess what I’m wondering is whether your science might be totally correct, but is being misused by less scrupulous people. As far as I can tell, the “accepted science” and the politics seem to always go hand-in-hand. Is there such a thing as you having the science down correctly and mankind not being on the brink of extinction? Serious question.

21. mkelly says:

Joel has yet to write one radiative heat transfer equation that shows the transfer of thermal energy (heat) from the atmosphere to the ground. I have asked him several time what is the emissivity of CO2 he would use in the formula and no answer. He and others say back radiation causes the surface to go to a higher temperature but when pointed out that if T1=T2 then ZERO watts per meter squared are transferred he fails to grasp it is temperature difference alone that is the driving force in heat transfer. The atmosphere gets its heat from the surface and a thing cannot heat itself.

22. Markus Fitzhenry. says:

Why is the surface temperature of the moon during almost perpendicular sun exposure remarkably higher than the ground surface temperature in comparable areas on our Earth?

Compared to the moon surface, the poor result for the Earth ground surface temperature, is achieved under the main stream idea that the earth has a heating greenhouse effect. The moon because of lack of an atmosphere is however without such an effect. The reason for the higher temperatures on the moon cannot be that the moon day is longer than Earth day.

In the sun at noon the (ground)surface temperature does not rise further, if it has achieved the highest value, which is reached already some minutes before noon (local time). After further 30 minutes of sun irradiation the value already measured does not continue to rise.

So, why doesn’t the surface continue to rise after just after noon if the ‘backradiation’ that continues emitting towards the surface during that period does not heat the surface?

Is the surface cooling at a lesser rate because of ‘backradiation’, that has not increased the surface temp just after noon?

This term ‘Greenhouse’ confuses me, surely, atmospheric gases are a mechanism that cools not warms. I think Co2 molecules in atmosphere effect a greater rate of radiation to space of LWR and a greater rate of reflection of SWR with a minimal effect from DLWR to the surface temperature.

23. Ulric Lyons says:

Markus Fitzhenry. says:
February 22, 2012 at 1:38 am

“Why is the surface temperature of the moon during almost perpendicular sun exposure remarkably higher than the ground surface temperature in comparable areas on our Earth?”

How do they measure it ? it has no atmosphere. The 120°C figure is the same for an object outside Earth`s atmosphere in direct sunlight. Surely the temperature of the Moon has to be in its surface and not the temperature of direct sunshine in the vacuum above its surface.
http://education.ksc.nasa.gov/esmdspacegrant/lunarregolithexcavatorcourse/chapter7.htm

24. Ulric Lyons says:

The low temperature for equatorial Lunar soil (i.e. through the 14d Lunar night) is 185K. The coldest temperature measured on Earth was 184K (−89.2 °C) at Vostok.

Here is a simple experiment that can be conducted outdoors at night. Take a matt black square of aluminium and place in a shallow EPS foam tray. Through the bottom of the tray attach a peltier cooler to the aluminium plate. Use silver heatsink paste to link a probe thermometer to the underside of the aluminium plate. Cover the tray with microwave safe cling wrap (IR transparent) and fill the space over the plate with dry nitrogen. Cool the plate to below 0C, then shut off the peltier device. We are told around 300 watts per m2 should be incident upon the plate. How quickly does DWLWIR take to heat the plate up? Now direct sufficient halogen down lights at the plate to equal 300 watts m2. What happens?

26. Markus Fitzhenry. says:

‘Ulric Lyons says:
February 22, 2012 at 3:04 am
The low temperature for equatorial Lunar soil (i.e. through the 14d Lunar night) is 185K. The coldest temperature measured on Earth was 184K (−89.2 °C) at Vostok.’

Can’t say I’m amazed at that there is similar equal low temp for a planetary, body bathed in the temperature of space with or without a atmosphere.

You needed moon measurements for highest surface temperature of body without a atmosphere, which is completely different for a body with atmosphere.

http://lunar.gsfc.nasa.gov/moonfacts.html

27. Stephen Wilde says:

I said:

“I’m not sure that the back radiation from clouds is significant.”

Hans replied:

“I can assure you that a cloud cover in midwinter in Stockholm area (59 latitude north) means it is about 5-10C warmer than if the sky is clear”

Is that from backradiation specifically from the cloud though ? Such cloud would normally be advected in from warmer climes with the warmth constantly refreshed by the prevailing winds.

A cloud is at the same temperature as the air in which it floats and so should not radiate energy any more than that air would in the absence of the cloud. A cloud forms when the ambient temperature of the air in which the water vapour finds itself cools to below the dew point. When the cloud forms does it suddenly start radiating at a temperature higher than that ambient temperature ?

So, if the temperature at the ground is dictated by the Gas Laws /ATE and not the temperature of the air (or clouds) above then backradiation from higher levels cannot be a significant factor whether from clouds or clear air.

The air circulation and consequent mixing is the process whereby the system tries to maintain the pressure induced lapse rate despite compositional variations in the atmosphere and clouds come and go as part of that circulation and mixing so they should be a consequence rather than a cause.

As far as I can see at the moment the temperature of the air molecules at or just above the surface dictates the dynamic energy exchange between surface and air above and the temperature of the air higher up is irrelevant to that low level exchange. At present atmospheric pressure the value of that exchange at the surface between air and atmosphere appears to be in the region of 150Wm2. which serves to balance the Earth’s energy budget.

Thus backradiation cannot be a significant factor whether from clouds or clear air. If it were then the Gas Laws would be falsified wouldn’t they ?

There could be no concept of a dry adiabatic lapse rate if water vapour as a GHG were able to change the baseline lapse rate set by pressure.

28. @ Markus Fitzhenry.: February 22, 2012 at 1:38 am

The Earth’s atmosphere insulates the surface to a significant extent because it absorbs and reflects nearly a third of all incident solar radiation. Carbon dioxide also helps insulate the surface from some of the IR radiation from the Sun – this IR being about half the Sun’s radiation. So carbon dioxide sends some of this to space as backradiation, thus adding to the cooling effect of the atmosphere during daylight hours.

The Moon does not have an atmosphere keeping it cool in its daylight hours, so it receives much more radiation. It also has daylight for about 13 Earth days, so it can indeed keep warming more each Earth day as thermal energy seeps into its surface and stays there until its next night.

The Earth’s surface includes the oceans, and solar radiation in the SW spectrum penetrates deep into the oceans and only gets converted to thermal energy well below the surface. The IR component gets converted higher up, so the water does indeed also warm at the surface on a sunny morning. But the thermal energy deeper down will take some time to rise by convection, and this can keep the surface warming beyond noon.

Also, the warmth of the morning is still diffusing back into the lower atmosphere, so even above land surfaces the surface and the air we stand in can keep warming past noon. Why not anyway? There can be just as much solar radiation at 1.00pm as there was at 11.00am.

There is no logical reason why noon should be a maximum temperature. The maximum is reached when the energy input from the Sun equals the rate at which conductivity and convection rates allow the energy to escape to the atmosphere. There is no reason why this should not be early afternoon.

29. Stephen Wilde says:

SergeiMK says:
February 21, 2012 at 11:23 pm

“Please note this is measured IR near the surface, coming from all directions above the level of the receivers. It DOES NOT measure the heat of O2/N2/etc. ”

Isn’t that just the temperature of the air molecules around the receivers ?

30. Stephen Wilde says:

Joel said:

“It (the radiative greenhouse effect) increases the surface temperature because it raises the effective radiating level, and hence you have to extrapolate down further from this level (where the temperature is 255 K) to get the temperature at the surface, as I showed by example in my second point (3). ”

Lets look at this more closely because I don’t think one can extrapolate back down to the surface as per the S-B equations just because the effective radiating height changes as a result of a change in the environmental (as opposed to the dry adiabatic) lapse rate.

Raising the effective radiating height involves increasing the rate of energy flow through the entire system. Convection goes higher carrying more energy out of the system at a faster rate.

If that height rises as a result of more energy flowing through the system such as from increased solar input then one will see greater total energy content within the system at any given time leading to a higher surface temperature AND a higher effective radiating height.

But what if one sees an increase in the effective radiating height WITHOUT any increase in solar input so that there is no more energy content within the system ?

In that case energy out would exceed energy in and the system would get colder.

As far as GHGs are concerned Joel suggests that an increase causes a rise in the effective radiating height (lets assume he is right on that) but in that situation no more energy is being added to the system from the sun so in theory that should cause overall cooling due to a decline in total system energy content.

One can get around that by accepting that, due to their downward radiating, GHGs would (possibly) delay the exit of energy from the system so that would offset the potential cooling that would otherwise result from a rise in the effective radiating height.

BUT that just gets us back to where we were before with the same surface temperature because the faster throughput of energy via the raised effective radiating height offsets the delay in energy transmission caused by the downward radiation from more GHGs.We have changed the environmental lapse rate below the tropopause but not the dry adiabatic lapse rate which applies to the whole system from surface to space. There has been no change in total system energy content because a speeding up in one part of the system has been offset by a slowdown in another part.

To get a higher surface temperature as well as a raised effective radiating height one needs to increase total system energy throughput AND content. That results in a higher atmosphere with greater volume AND a higher surface temperature.

More GHGS do not achieve that. They simply redistribute the energy that is already available and so if the volume of the atmosphere increases from a rise in the effective radiating height then the environmental lapse rate changes for a section of the atmosphere but not the dry adiabatic lapse rate for the whole system so that surface temperature (and total system energy content) stays the same.

31. Joel – your explanation of the lapse rate is not correct in that it is not going to be zero just because you remove GHG’s. You have correctly quoted the formula which includes the acceleration due to gravity. The adiabatic lapse rates have nothing to do with GHG’s. Your y = mx + b still has the same m and the same b.with or without GHG’s. Basically the temperature plot swivels around the mean (say, 255K) which is somewhere up in the atmosphere.

Radiation from the atmosphere can originate at almost any temperature and so any altitude. That which gets back to the surface does nothing, as explained in my lengthy post above. It is as good as diffuse reflection. Its energy cannot be converted to thermal energy until it strikes a cooler target than its source, so it will usually get closer to space each trip up. But it will never be absorbed and converted to thermal energy by the warmer surface, and thus never slow the rate of cooling thereof.

The altitude at which it is radiated doesn’t matter.

So, the mean adiabatic lapse rate is determined, not by carbon dioxide, but by the acceleration due to gravity, the mass of the atmosphere and, to some extent, relative humidity which mostly averages out. The drop in temperatures between the surface and the tropopause has been very close to constant in all the years of records shown on the NASA site since the end of 2002.

My point is that the mean surface temperature is dictated by these two values – the 255K (or whatever the exact figure is) and the lapse rate. Carbon dioxide cannot affect either.

Both the surface and the atmosphere will simply shed energy faster if they get a little warmer, thus tending back to the mean.

There is no long term TOA net difference. The net radiative flux varies between about 99.5% and 100.5% of incoming radiation. This is just random noise or short-term cycles.

Longer natural cycles may have to do with variations in the effective power in solar radiation (affecting that 255K figure) and maybe the thermal energy generated under the surface. Small variations in the latter over many thousands of revolutions of the Earth could have a cumulative effect. The very fact that the terrestrial heat flow is low means that the massive quantity of thermal energy from the surface down to the core stays fairly much the same and brings about a stabilising effect as I have explained on other posts.

32. greg elliott says:

If GHG is responsible for the lapse rate, then adding more CO2 to the atmosphere could only increase the lapse rate. This would increase the temperature difference between the surface and the upper atmosphere, increasing convection and provide a net cooling of the surface. Thus increasing GHG would lead to cooling.

It is thus a nonsense to argue that increasing CO2 would lead to surface warming, as this would mean that CO2 would need to first warm the upper atmosphere (the atmospheric hot spot) which would reduce the lapse rate. This would lead to the contradiction that increasing CO2 must both increase and decrease the lapse rate at the same time.

The basic problem lies in the mistaken assumption that convection can only exist in the presence of GHG. This is a nonsensical idea. A pure N2 atmosphere would still have convection, with N2 rising during daytime and towards the equator and sinking at nighttime and towards the poles.

The simple fact is that convection can only exist in the presence of gravity. Take away GHG and convection will still occur. Take away gravity and there can be no convection. The other ingredient required is a temperature difference, as occurs between day and night, between the equator and the poles.

Whether it is the oceans of the atmosphere, convection will take place to try and eliminate the temperature difference. GHG can also driver convection, but this then means it is providing a net cooling of the atmosphere, not a heating, and the GHG effect cannot exist.

33. kuhnkat says:

Hans,

when the temps are 5-10c warmer with clouds, is there any wind?? Are we sure there is usual convection happening or are we partly seeing the effect of a lack of wind and/or convection??

34. tallbloke says:

Joel says:
By the way, it is probably worth putting this strange misconception that the Ideal Gas Law implies that a certain surface pressure leads to a certain surface temperature to rest once and for all.

As Ray Pierrehumbert points out in his book (Section 2.5), you can take the hydrostatic relation

(dp/dz) = -rho*g

where p = pressure, z = height above the surface, g = gravitational acceleration, and rho = mass density. If you now substitute in the Ideal Gas Law, p = rho*R*T/M where M = (average) molecular mass, and R = ideal gas constant (8.31 J/[mol*K in SI units), you get

(dp/dz) = -g*M*p/(R*T).

Assuming everything else but the temperature and pressure are constant with height z, you can integrate this differential equation to get the solution for pressure as a function of height:

p(z) = p_surface * exp(-g*z/[R*Q])

where p_surface is the surface pressure and Q is defined as z divided by the integral from 0 to z of dz’ / T(z’). [Q is apparently called “the harmonic mean temperature”.]

What this shows you is that, given any surface pressure, you can specify any temperature distribution with height that your heart desires and then determine the pressure as a function of height.

Hence, we have used the Ideal Gas Law to show that, far from determining the temperature at the surface, this Law together with the hydrostatic relation still doesn’t provide any constraint whatsoever on the temperature at the surface…or even the temperature distribution with height!

[Reply] Hi Joel, your confusion here is exemplified by the first question you asked of N&Z on publication of their reply to comments part 1. “What isobaric process?”. The key point is that the volume of the atmosphere is not constrained by space. The atmosphere is warmed by for example, a change in TOA insolation due to Earth’s varying distance from the Sun as it moves from aphelion to perihelion; it is free to expand upwards. Density therefore is a function of temperature, which in turn is a function of pressure and insolation at TOA. The freedom of expansion of the atmosphere means the pressure profile with altitude will be determined by mass and gravity alone, not temperature. The dry lapse rate will therefore remain constant. I suggest you have a think about that and come back with your equations re-arranged so that they are more relevant to the actualité. Drop a note to Ray as well. 😉 Cheers – TB.

35. Mydogsgotnonose says:

Michael hart; second order effects…..I am not an IR expert however one such person has told me that such effects are definitely excluded because of quantum factors.

The classical way of analysing this is to understand that every process requires an activation energy and it is simply far too high to add the whole quantum of energy to the kinetic energy of N2/O2 [the vibrational energy states are far too energetic which is why you need high temperatures to activate them].

In 1993, Will Happer, probably the US’ top IR physicist resigned as director of research of the DoE because he apparently refused to lie for Gore, reportedly warning that climate science’s 100% direct thermalisation assumption was wrong.

My suspicion is that climate science was set up deliberately to use peer reviewed research of the past that was know to be simplistic just to get the high predicted warming. That was successful and the aim since then has been to prevent publication of the truth. If correct, this is the biggest scientific hoax in history.

FYI I have identified the new physics which explains why the net AIE is the wrong sign and accounts for most (A)GW, GHG-AGW cannot be more than ~15% of the IPCC’s median claim of 3 K/doubled [CO2]. You get this by scaling real present GHG warming to ~9 K and putting net AIE to zero. however, I think I am on the verge of identifying the mechanism by which the atmosphere self-reguates IR optical depth to a constant level, so there is probably no GHG-AGW.

Thus most recent warming is probably biofeedback reduction of cloud albedo in the Arctic via the new physics: http://bobtisdale.files.wordpress.com/2012/01/figure-102.png

This is written up. I was amazed that all the experiments i would have wanted to do have been done and all it needed was the physics’ insight to assemble the pieces. I hope to bypass the peer review block in an unusual way.

36. greg elliott says:
February 22, 2012 at 7:05 am

“The basic problem lies in the mistaken assumption that convection can only exist in the presence of GHG.”
____________________________________________________________

Spot on Greg about the convection: it’s unbelievable that an author here would write what he wrote.

However, I have to disagree about anything that assumes radiation from the atmosphere can slow the rate of cooling of the surface – but please read my other posts on that topic.

But speaking of cooling effects, about half the Sun’s incident radiation is in the near IR part of the spectrum and WV and CO2 do absorb some of this, and some of what they absorb is sent back to space as “backradiation” going upwards. Obviously this helps the atmosphere in its task of cooling the surface by insulating it from about a third of the Sun’s heat in daylight hours.

37. Markus Fitzhenry says:

Douglas Cotton says:
‘February 22, 2012 at 6:15 am

Whether it is the oceans of the atmosphere, convection will take place to try and eliminate the temperature difference. GHG can also driver convection, but this then means it is providing a net cooling of the atmosphere, not a heating, and the GHG effect cannot exist.’

Thanks Doug, I’ll take it that immediately after the receipt of Suns maximum IR for that day, regardless of it’s perihelion of Earth, the surface net absorption of IR decreases, assuming there is no diffusion, only ‘backradiation’ from a cooling atmosphere?

38. Hans says:

kuhnkat says:

February 22, 2012 at 7:41 am
“Hans, when the temps are 5-10c warmer with clouds, is there any wind?? Are we sure there is usual convection happening or are we partly seeing the effect of a lack of wind and/or convection??”

Your question is very relevant. When working about 50 km north of the polar circle during winter I got very much aware of the importance of topografi on temprature. Along the border the Mounio river is floating. During winter it is covered by about 1 meter of ice. On top of the river ice cold air is floating downstreams when there is no or little wind. It is jsut a river of cold air. The average winter temperature at Kauniusjounsuu at the river was about 5C colder than at Pajala about 20 km away at a higher altitude. Cold air can easily gather on top of an inland lake in a shallow layer and the temperature can be -15C lower than at a hill top 500 meter higher but rather close by. This process is most developed during clear sky and no or little wind.

Yes, I am sure that my statement is valid during “normal” wind conditions wintertime around Stockholm and that the temperture decrease during night time is far less when there are clouds in the sky. Personally I favour the opinion that IR radiation from the surface is caught by the clouds and most of this energy is sent back to earth´s surface from the lower aprt of the clouds. It also means that the obligatory night surface temperature inversion during clear nights are prevented to evolve so much when there are clouds around.

The temperature change rather quickly when the cloud cover is changing which is very common in this area.There exist excellent meteorological data since more than 100 years in many localities in Sweden so my statment can easily be verified or falsified. The effect is eaiser to notice when lakes are ice covered as they are now and when solar irradiation is small or absent. This phenomenon might be best to investigate when there is no solar irradiation at al (wintertime above the polar circle).

It is important to separate these two effects from each other.

39. Hans says:

Rog says:
“Hence, we have used the Ideal Gas Law to show that, far from determining the temperature at the surface, this Law together with the hydrostatic relation still doesn’t provide any constraint whatsoever on the temperature at the surface…or even the temperature distribution with height!”

Correct: To get a step further and derive dt/dz = -g/Cp you have to introduce an air parcel which is energetically insulated.

Any planetary atmosphere is in an approximate “long term” steady state condition. It means that seasonal averaged temperatures (global and regional) can be calculated and depend on a solar irradiation balance. However, the evolution of DALR is always local since the physical conditions are differernt at different locallities. DALR can and will develope ragardless of what the surface temperature happen to be at a certain locallity. It will always develope from the surface and upwards when sun has been shining on land during a day. The lifting air transport energy upwards and make it easy for the atmosphere to arrange itself adiabatically (equal amount of total energy per mass unit). This process has little to do with radiative processes. You are correct: the derivation you are showing does not mention the common habit of the troposphere to arrange itself aidabatically. It´s is an added constraint that often can be applied to earth´s atmosphere but not always. It can almost always be applied to the Venusian troposphre. Several physical processes at work is why the US 1976 Standard Atmosphere has a temperature laps rate in the troposphere of 6.5 K/km and not the
-9.8 K/km of the DALR. Dissipation of energy is one process of several that decides the atmospheric temperature profile on earth but it is very probably the dominant one.

40. Ronaldo says:

This may be a simple minded view, but I suggest that the effect of clouds on surface temperature during winter nights is simply that without cloud cover the sink temperature for LWR is that of outer space. With cloud cover the LWR is absorbed by the cloud at a temperature which must be above the freezing point of water and with a heat capacity (specific heat plus heat of vaporisation) sufficient to absorb the heat energy without completely evaporating the cloud. Eventually transfer occurs from the top of the cloud via radiation to outer space. (Because of the thermal capacity of this cloud ‘blanket’, the nett effect is to reduce the rate of cooling of the earth’s surface.

41. tallbloke says:

More responses from Joel:

Markus Fitzhenry says: “Why is the surface temperature of the moon during almost perpendicular sun exposure remarkably higher than the ground surface temperature in comparable areas on our Earth?”

Because the Earth has an atmosphere and an ocean which give it a large specific heat (energy storage mechanism) and much larger energy transfer mechanisms. The greenhouse mechanism is a mechanism by which the AVERAGE surface temperature AND the average power emitted by the surface are increased.

Atmospheres cause other effects other than just the greenhouse effect; for example, clouds can cause an increase in albedo and the atmosphere can move energy around (and store energy). In fact, because of the fact that average power emitted by the surface is proportional to T^4, not T, the average temperature can increase without any change in the average power emitted just by the temperature becoming more uniform. This is what Nikolov and Zeller have recognized by the 133 K temperature enhancement. However, it is worthwhile to keep distinct average temperature enhancements associated with actual increases in actual power emitted, which necessarily require a radiative greenhouse effect, from average temperature enhancements without any change in actual power emitted, which can simply come about due to having a different temperature distribution.
—————

Stephen Wilde says:

“But what if one sees an increase in the effective radiating height WITHOUT any increase in solar input so that there is no more energy content within the system ?

In that case energy out would exceed energy in and the system would get colder.

As far as GHGs are concerned Joel suggests that an increase causes a rise in the effective radiating height (lets assume he is right on that) but in that situation no more energy is being added to the system from the sun so in theory that should cause overall cooling due to a decline in total system energy content.”

You are running yourself in circles here. Let me describe the process by which warming occurs in more detail. For simplicity, imagine an instantaneous increase in GHGs (say, a doubling of CO2 levels). Before this increase, the Earth was in radiative balance (emitting and absorbing 240 W/m^2). After this increase, the Earth will no longer be in radiative balance because the effective emission layer (i.e., the layer from which radiation can successfully escape to space without being re-absorbed again) is higher in the atmosphere and thus colder. Since this layer is colder, it emits less radiation to space, so that the Earth is now emitting 236 W/m^2 while still absorbing 240 W/m^2 from the sun.

Since the Earth+atmosphere is now receiving 4 W/m^2 more than it is emitting, it will warm up. As it warms, the amount that it emits back into space increases until the average temperature at the new effective radiating level is equal to the average temperature at the old effective radiating level (255 K) before the CO2 increase occurred. At this point, radiative balance has been restored but the temperature throughout the troposphere has increased (to the first approximation in a way that maintains the same lapse rate it had before).
——————–

greg elliott said: “If GHG is responsible for the lapse rate, then adding more CO2 to the atmosphere could only increase the lapse rate. This would increase the temperature difference between the surface and the upper atmosphere, increasing convection and provide a net cooling of the surface. Thus increasing GHG would lead to cooling.”

(1) I never said that the GHG are responsible for the lapse rate.

(2) I have clearly said that the mechanism by which warming occurs has nothing to do with increasing the lapse rate … It does not increase.

“The basic problem lies in the mistaken assumption that convection can only exist in the presence of GHG.”

Since not assumption was made, no such problem exists. I suggest you re-read my post again more carefully.

————

tallbloke says: “The key point is that the volume of the atmosphere is not constrained by space.”

That is why there are three rather than 4 variables in the ideal gas law, i.e., n and V are not independent variables; only their ratio matters.

tallbloke says: “The dry lapse rate will therefore remain constant.”

If you want the lapse rate to remain constant, then put in a constant lapse rate. That is a perfectly allowed temperature distribution.

tallbloke says: “I suggest you have a think about that and come back with your equations re-arranged so that they are more relevant to the actualité. Drop a note to Ray as well.”

I have shown that the ideal gas law + the hydrostatic relation + a specified surface pressure do not constrain the temperature at the surface. If you believe that the equations are wrong or that there is some other specification that is missing, then it is your job to explain how this comes about, not mine to try to turn your prose into equations. My current opinion is that your prose cannot be turned into equations, but you are certainly welcome to prove me wrong.

————

Doug Cotton says:

“Joel – your explanation of the lapse rate is not correct in that it is not going to be zero just because you remove GHG’s. You have correctly quoted the formula which includes the acceleration due to gravity. The adiabatic lapse rates have nothing to do with GHG’s. Your y = mx + b still has the same m and the same b.with or without GHG’s.”

I never said that the adiabatic lapse rate has anythingto do with GHGs, nor that the lapse rate changed with the addition of GHGs. You are right that m essentially does not change with GHGs. However, b does because the constraint provided by radiative balance is that the temperature has to be 255 K at the effective radiating level and that height changes with the addition of GHGs.

“The altitude at which it is radiated doesn’t matter.”

Yes, it does as I explained in my post (and have elaborated on a bit in a response to Stephen WIlde).

“My point is that the mean surface temperature is dictated by these two values – the 255K (or whatever the exact figure is) and the lapse rate. Carbon dioxide cannot affect either.”

Carbon dioxide effects the height in the atmosphere (effective radiating level) at which the mean temperature has to be 255 K. As that height rises (with the lapse rate remaining approximately constant), the surface temperature rises.

42. jjthom says:

Stephen Wilde says: February 22, 2012 at 5:17 am
“Please note this is measured IR near the surface, coming from all directions above the level of the receivers. It DOES NOT measure the heat of O2/N2/etc. ”
Isn’t that just the temperature of the air molecules around the receivers ?
==========
No the receivers measure IR not “temperature” O2 N2 == air do not radiate so their temperature will not affect the measured IR from GHGs

43. tallbloke says:

Joel says:
I have shown that the ideal gas law + the hydrostatic relation + a specified surface pressure do not constrain the temperature at the surface.

What you’ve shown is that you can algebraicly re-arrange the static situation in a non-realistic way to make temperature appear to be independent of surface pressure. Along the way you missed the key elements of N&Z’s theory, which deals with the dynamic situation created by the throughput of solar energy in a gaseous system subject to gravity.

My current opinion is that your prose cannot be turned into equations

If you don’t like my prose, then I suggest you re-read N&Z’s equations until you understand them.

44. Will says:

Joel Shore says:
February 21, 2012 at 10:24 pm

” It does not increase the lapse rate. It increases the surface temperature because it raises the effective radiating level, and hence you have to extrapolate down further from this level (where the temperature is 255 K) to get the temperature at the surface, as I showed by example in my second point (3).”

This is a pure circular argument.

What you are saying here Mr Shore is that the “greenhouse effect” of CO2 warming is real because of the “greenhouse effect” of CO2 warming.

It is based as ever on an unproven hypothesis

There is however very real evidence such as that provided by Harry and others, that CO2 plays no role in atmospheric temperatures.

There is also plenty of historical evidence in the geological record which independently verifies the fact that atmospheric temperature does not follow atmospheric CO2 content.

There is also more recent evidence that over the last 10-15 years, in-spite of ever increasing CO2
emissions both natural and human, temperatures have failed to comply with wishful thinking.

What you need to do is simply provide empirical evidence that increasing the ratio of CO2 to a mass of air with a CO2 content of 365 ppm or below (or above for that matter), will increase the temperature of that air mass.

This is a simple thing to test and can be achieved for a cost of just a few hundred pounds or so.

Two identical greenhouses side by side at equal latitude.

Increase CO2 levels in one greenhouse and observe.

One way or the other this test would settle the debate once and for all.

Do the test Mr Shore. Then you may have something to contribute.

One thing the S/B equation tells us is that temperature is NOT determined by radiation, which is defined by frequency but by mass, which is defined by thermodynamics.

This is the exact opposite of what the “greenhouse effect” hypothesis is based upon.

That is a very easy question to answer in my view.

45. Stephen Wilde says:

Joel said:

“imagine an instantaneous increase in GHGs (say, a doubling of CO2 levels). Before this increase, the Earth was in radiative balance (emitting and absorbing 240 W/m^2). After this increase, the Earth will no longer be in radiative balance because the effective emission layer (i.e., the layer from which radiation can successfully escape to space without being re-absorbed again) is higher in the atmosphere and thus colder. Since this layer is colder, it emits less radiation to space, so that the Earth is now emitting 236 W/m^2 while still absorbing 240 W/m^2 from the sun.”

An alternative suggestion:

GHGs add to the energy content of the air alone by slowing down energy loss to space but also add to the rate of energy throughput by raising the effective radiating height.for a net zero effect on the surface temperature.

The volume of the atmosphere has increased but the slope of the dry adiabatic lapse rate has not changed from surface to top of atmosphere because there is no change in pressure at the surface. Gravity alone sets the slope of the dry adiabatic lapse rate.

Instead, the slope of the environmental lapse rate changes between surface and the effective radiating height so that the surface temperature stays as before and the temperature at the effective radiating height remains the same as before despite the raising of the effective radiating height.

As long as the dry adiabatic lase rate is maintained on average between surface and top of atmosphere the environmental rates within layers of the atmosphere are free to adopt whatever slopes are necessary to adjust for the effects of compositional variety from planet to planet.

Hence the well known vertical structure of Earth’s atmosphere which actually shows a sideways ‘W’ shape from surface to space.

Other planets, other compositions, other vertical structures.

And that is why one can only apply S-B from a position outside the atmosphere.

46. Markus Fitzhenry says:

Joel Shore says;

However, it is worthwhile to keep distinct average temperature enhancements associated with actual increases in actual power emitted, which necessarily require a radiative greenhouse effect, from average temperature enhancements without any change in actual power emitted, which can simply come about due to having a different temperature distribution.”

Excepting the above, I agree with your remarks, thank you.

Without referring, I did consider the Nikolov and Zeller hypotheses to mean the distribution was the force of pressure caused by gravity and the enhancement of the atmosphere was set by it. Moreover dynamism controls the uniform distribution of temperature not a ‘backradiation’ greenhouse effect, whatever is the dynamic state of a planets particles.

47. Tenuc says:

Mydogsgotnonose says:
February 22, 2012 at 9:08 am
“…FYI I have identified the new physics which explains why the net AIE is the wrong sign and accounts for most (A)GW, GHG-AGW cannot be more than ~15% of the IPCC’s median claim of 3 K/doubled [CO2]…”

Interesting paper which indicates that the aerosol indirect effect is poorly understood and the effect had an inconsistent representation in AR4 GCM’s…

What governs the spread in shortwave forcings in the transient IPCC AR4 models?
T. Storelvmo, U. Lohmann, and R. Bennartz – Jan 2009

48. Ulric Lyons says:

Douglas Cotton says:
February 22, 2012 at 9:30 am
“But speaking of cooling effects, about half the Sun’s incident radiation is in the near IR part of the spectrum and WV and CO2 do absorb some of this, and some of what they absorb is sent back to space as “backradiation” going upwards. Obviously this helps the atmosphere in its task of cooling the surface by insulating it from about a third of the Sun’s heat in daylight hours.”

Cloud albedo reflects in total about 30%. There are no CO2 absorbtion bands for incoming radiation. WV absorbs a little incoming near IR

49. RKS says:

Mydogsgotnonose says:
February 21, 2012 at 10:58 pm
Not being a climatologist or climate scientist, but having a very good grounding in thermodynamics and physics, also being a lateral thinker, I have a rather different viewpoint to most people.The first thing that climate science should unlearn is the concept of direct thermalisation of absorbed IR energy to the N2 and O2 majority molecules. it can’t happen because that energy is quantised, so can only be transferred to another GHG molecule.

Also the argument that in the ~1 ms that it takes for the excited molecule to re-emit that photon, it has about 1000 collisions to transfer the energy is also bunkum because the principle of Local Thermodynamic Equilibrium means that another excited molecule [~5% of CO2 at room temperature] will emit the same energy photon in a random direction, restoring equilibrium. This failure to understand that molecules have no history appears to be another basic fault of climate science.

So, I believe there can be no direct radiative greenhouse effect! However, Tyndall and the modern PET bottle experiments apparently prove it exists. How? Well, both experiments are effectively constant volume so much of the higher temperature of the CO2 is because it has expanded and the expansion is constrained. Unscrew the cap, the temperature rise is much lower and the real heating is probably at the walls of the container! In my view, this is a serious and very basic mistake by climate science.

There a pseudo GHG effect. Thinking this out is taking some time because it appears to be new science and the concept of thermodynamic temperature for random IR scattering is obscure. However, the scattered IR will thermalise at second phases that are cooler than the source temperature of most of the radiated IR that arrives: that could be the Earth surface temperature. If the IR impacts a warmer surface, it cannot thermalise because to do so would be a brwach of the 2nd law of Thermodynamics.

The Prevost Exchange Energy coming to the earth’s surface will vary considerably depending on the closeness of clouds. Hence when you measure the apparent emissivity, it will vary considerably. I can’t see that any of this basic thinking has been done in climate science. None of the models can predict climate and it’ll take a lot of work to do so: I’d guess a decade.>>>>>

I always enjoy you clear concise contributions to the discussion free of the prejudices of the climate science community.

My attraction to the work of N&Z is because of their non pretentious use of bog standard physics.

As yo suggest, until the climate science community can rid themselves of the ingrained preconceptions they use to account for empirical data, It may well take a decade to turn the AGW juggernaut around.

50. Ulric Lyons says:

Markus Fitzhenry. says:
February 22, 2012 at 3:21 am
“You needed moon measurements for highest surface temperature of body without a atmosphere, which is completely different for a body with atmosphere.”

Table 01 and figure 06:
http://education.ksc.nasa.gov/esmdspacegrant/lunarregolithexcavatorcourse/chapter7.htm

51. tallbloke says:

Joel says:

Stephen Wilde says:

“An alternative suggestion:

GHGs add to the energy content of the air alone by slowing down energy loss to space but also add to the rate of energy throughput by raising the effective radiating height.for a net zero effect on the surface temperature.”

What does “add to the rate of energy throughput by raising the effective radiating height” mean? What principle of physics says that increasing the effective radiating height will add to the rate of energy throughput?

“The volume of the atmosphere has increased but the slope of the dry adiabatic lapse rate has not changed from surface to top of atmosphere because there is no change in pressure at the surface. Gravity alone sets the slope of the dry adiabatic lapse rate.”

The dry adiabatic lapse rate is not the lapse rate between the surface and the top of the atmosphere. It is a stability criterion: Lapse rates steeper than the adiabatic lapse rate are unstable to convection whereas shallower lapse rates are not.

“Instead, the slope of the environmental lapse rate changes between surface and the effective radiating height so that the surface temperature stays as before and the temperature at the effective radiating height remains the same as before despite the raising of the effective radiating height.”

In the troposphere, the temperature with altitude tends to closely follow the appropriate adiabatic lapse rate.

“As long as the dry adiabatic lase rate is maintained on average between surface and top of atmosphere the environmental rates within layers of the atmosphere are free to adopt whatever slopes are necessary to adjust for the effects of compositional variety from planet to planet.”

Hence the well known vertical structure of Earth’s atmosphere which actually shows a sideways ‘W’ shape from surface to space.

There is no law saying that the lapse rate from the surface all the way to the top of the atmosphere has to be on average at the dry adiabatic lapse rate and in fact it is nowhere near that. Rather, the adiabatic lapse rate sets a stability criterion: Lapse rates steeper than the adiabatic lapse rate are unstable to convection and are driven back down to the adiabatic lapse rate. In the troposphere, the lapse rate is generally found to be close to the appropriate adiabatic lapse rate because the troposphere is strongly heated from below and cooled from above, and so convection tends to be the rule.

However, in the stratosphere it is not.

52. P.G. Sharrow says:

Joel Shore says: “the effective radiating level is at about 5 km”

An observation that is correct, but I am not sure it is for the right reasons. Convection seems to be poorly understood in the comments I see. While dry gasses do convect, do to thermal energy changes, water vapor is the most important, by far. In evaporation and condensation there is a change of 1600 to 1 in volume of space that is occupied. 1600 to 1 of volume as well as 530 units of energy! All the argument about black bodies, grey bodies, dry gas rates etc. is wonderful, BUT! WATER is the gorilla in the closet for the first 5 km! After that radiation theory and dry gas laws prevail. pg

53. Ulric Lyons says:

The density (mass/volume) of water vapor is 0.804 g/litre, which is significantly less than that of dry air at 1.27 g/liter at STP.

54. RKS says:

Mydogsgotnonose says:
February 22, 2012 at 9:08 am>>>>>>>>

Might I suggest you get in touch with Nick Nikolov.

I suggested to him that unbiased engineers would be more likely yo understand his theory that surface temperature is down to gas laws and thermodynamics alone.

His response, in a nutshell, was that he see how an engineer might be more successful in understanding his theory than a trained climate scientist whose thinking has been skewed by the radiative transfer concept, and that it would be another useful conduit to gain broader support for his theory among common people, in order to defeat the current nonsensical GH theory.

His opinions with which I agree.

If you wish to overturn the travesty which AGW proponents use to threaten our entire civilization, please get in touch with him at the following address ( also available in the header to his research paper ).

regards,

55. RKS says:

RKS says:
February 22, 2012 at 5:00 pm
Mydogsgotnonose says:
February 22, 2012 at 9:08 am>>>>>>>>

Might I suggest you get in touch with Nick Nikolov.>>>>>

OOPS, Must have forgotten my medication, I’ve never referred to Ned Nikolov as Nick.

Repeat after me – Ned Nikolov……………………..

56. Gras Albert says:

Wilde

A cloud is at the same temperature as the air in which it floats and so should not radiate energy any more than that air would in the absence of the cloud.

It depends, if we’re talking about convective cloud e.g. cumulus, the latent heat of condensation raises the temperature at cloud base, as a glider pilot I’ve flown in thousands of thermals and on hundreds of occasions continued the climb through cloud base, sometimes many thousands of feet above it. Depending on the lapse rate above cloud base the temperature rise due to LHoC can double or even triple the vertical velocity of the thermal, even if the rate of climb doesn’t increase above cloud base there is an observed temperature drop on leaving the cloud.

A cloud forms when the ambient temperature of the air in which the water vapour finds itself cools to below the dew point. When the cloud forms does it suddenly start radiating at a temperature higher than that ambient temperature ?

The answer is yes, if it’s convective cloud, the reason is LHoC

I’d also point out that in countries such as the UK where dry ground is a rarity thermal buoyancy is can be derived from increased water vapour caused by ground water evaporation, in this case the thermal temperature can be observed lower than the surrounding air mass, it remains buoyant because the high specific humidity of that thermal air mass results in a less dense parcel of air.

Air mass temperature change can also be observed with the visible sign of lee waves, lenticular clouds, which typically remain stationary over a ground location, forming (condensing) at the into wind edge and dissolving (evaporating) at the downwind edge, the air temperature at the leading edge is higher due to LHoC and lower at the trailing edge due to the converse.

Until the water droplets (cloud) freeze at which point the exothermic LHoC becomes endothermic LH of Fusion and the the air mass temperature falls.

PS Lee wave systems reach well into the Stratosphere (>100,000ft), can extend hundreds of miles from their source and can exist 24/7. I find it conspicuous that lee wave physics is absent from the atmospheric models used in GCMs!

57. Stephen Wilde says:

Gras Albert:

Thanks for that additional detail about clouds. It is clear that the situation with regard to any cloudy scenario is very complex and variable.

The problem is how to deal with the assumed downward radiation from clouds and /or clear sky (if there is any) when it is pressure that sets the temperature at the surface for a given level of solar input.

I’m sure that the energy exchange between surface and air only involves the air at or just above the surface and that any energy flow from higher up is irrelevant to the surface temperature.

That is why I reject the idea of backradiation as described by AGW proponents.

If pressure is the dominant feature as per the Gas Laws then there is no room or need for any warming effect from energy in the air higher up either by way of additional energy coming down or by way of a slowing of cooling. I think Ned said as much in one of his comments.

According to the Gas Laws pressure alone seems to set a temperature at the surface for a given level of solar input that cannot be exceeded unless one increases that pressure.

That makes sense if one regards pressure as a force restraining the kinetic energy of a group of molecules so that they stay within a certain volume of space.At some specific point the kinetic energy would overcome the restraint of pressure and the unit of air would expand instead of getting hotter.

I think the answer is that the VOLUME of the atmosphere is freely variable and that changing the volume would prevent a temperature rise at the surface in accordance with the Gas Law equation provided total energy flowing through the system does not increase..

A change in solar input changes the total energy flowing through the system and will consequently raise the surface temperature at any given pressure AND expand the volume of the entire atmosphere.

More GHGs do not change the total energy flowing through the system and so if they provoke an increase in atmospheric volume then they will fail to increase surface temperature.

GHGs would simply redistribute energy within the system without raising the surface temperature.

It is possible that they do not change atmospheric volume either if their radiative cooling to space offsets their radiative warming back to the surface but for the purpose of this comment I am accepting that they do have some net warming effect which increases atmospheric volume.

58. Will says:

Once again:

One thing the S/B equation tells us is that temperature is NOT determined by radiation, which is defined by frequency but by mass, which is defined by thermodynamics.

59. Paul Bahlin says:

Actually Stephen, couldn’t you consider a one meter high column (1 m^2 base) at the surface a 1 m^3 volume of constant energy since (within reason) PV is constant. Taking that assumption says that nT is also constant in that volume which then implies that (again neglecting convection and all the other stuff that is going on) that little cylinder might have a temperature held pretty close to the surface temp, which means it has to expel molecules to maintain its energy level as the surface temp goes up.

This isn’t really convection because it’s a molecular level phenomenon and there is no moving air parcel making it happen, and no displacement and backfilling. Nevertheless it represents energy moving away (taking energy) from the surface. During increasing surface temp it represents an energy source for the adjacent cylinder above it and during surface cooling it represents an energy sink as molecules move down to maintain the energy level.

Bonus! It’s doing work against gravity.

Double Bonus! Higher pressure atmospheres would imply more work.

Triple Bonus! It’s an insolation energy pump.

60. Markus Fitzhenry says:

Paul Bahlin says:
February 22, 2012 at 10:53 pm

“Nevertheless it represents energy moving away (taking energy) from the surface. During increasing surface temp it represents an energy source for the adjacent cylinder above it and during surface cooling it represents an energy sink as molecules move down to maintain the energy level.”

Quadruple bonus! It’s a perpetual isolation energy pump.

Potential energy returns to levels prior to the commencement of the phenomenon. The force of pressure means energy conservation is maintained. Heat is caused by radiation to a colder body. Cold is caused by radiation from a warmer body.

Atmospheric gases would simply redistribute energy within the system without raising the surface temperature.

61. tallbloke says:

Joel says:
Stephen Wilde says: “According to the Gas Laws pressure alone seems to set a temperature at the surface for a given level of solar input that cannot be exceeded unless one increases that pressure.”

Nobody has demonstrated that the gas laws say that and nobody has explained what exactly needs to be added to my demonstration that the ideal gas law + hydrostatic equation + surface pressure do not determine the temperature distribution.

This claim that the Ideal Gas Laws somehow imply this result has simply not been demonstrated in any way, shape, or form.

tallbloke says: “If you don’t like my prose, then I suggest you re-read N&Z’s equations until you understand them.”

N&Z’s equations are just a fit to data and do not address this question.

62. tallbloke says:

Joel seems to have shifted from trying to defend the radiative greenhouse theory to attacking N&Z’s theory (using inappropriate formulations relative to their line of argument).

Why might that be?

63. RKS says:

Stephen Wilde says:
February 22, 2012 at 10:07 pm>>>>>>>>>>

Reading the latter part of the thread, where contributors are able to discuss pressure induce thermal enhancement, (described by me on the N&Z thread as a sort of insolation amplifier, and rather nicely by Paul Bahlin as an insolation energy pump) without any hostile challenge, would it be safe to assume that for a lot on this thread AGW by radiative feedback is pure fantasy?

By the way Stephen, I responded to you on the N&Z thread regarding your diode/capacitor climate model, and made a few suggestions.

regards,

64. Bob_FJ says:

Joel Shore,

For the Earth in its current state, the effective radiating level is at about 5 km. This value together with the average lapse rate of ~6.5 C per km then allows us to determine the average temperature of the surface by extrapolation: 255 K + (5 km)*(6.5 C / km) = 287.5 K.

However, the Trenberth energy balance cartoon, for which you have elsewhere stated (paraphrasing), “the numbers are fine”, gives that ~25% of the heat loss from the surface is via radiation directly to space. The other ~75% surface heat loss is ultimately radiated to space over a wide range of altitudes, not some conceptual gas “surface”. Thus your calculation for surface T based on a lapse rate of ~6.5 C/Km and a “radiative cut-off” at 5 Km is deeply flawed, even if the result pleases your purpose.
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
BTW, the lapse rate average of~6.5 C/Km has some considerable temporal and spatial variations, including dryness, and I find the concept of averaging it to do a meaningful calculation as you propose to be highly controversial, and much the same can be said about average global T.

This last bit is purely a BTW, please address only the simpler issues above the line.

65. wayne says:

“Actually Stephen, couldn’t you consider a one meter high column (1 m^2 base) at the surface a 1 m^3 volume of constant energy since (within reason) PV is constant. Taking that assumption says that nT is also constant in that volume which then implies that (again neglecting convection and all the other stuff that is going on) that little cylinder might have a temperature held pretty close to the surface temp, which means it has to expel molecules to maintain its energy level as the surface temp goes up.”

P * V = n * R * T

 P * V / R / n = T

n = (1.225 kg/m^3) / (0.02896 kg/mol) = 42.30 mol/kg

now, P being average of 101325 Pa so:

101325[P] * 1[V] / 8.31451[R] / 42.30[n] = 288.10 K mean surface temperature.

Since ‘P’, ‘V’, ‘R’, and ‘n’ are averaged constants here on Earth; therefore, the mean temperature is also constant on the average at the surface. Just remember, Joel Shore is no physicist, he is a propagandist.

Now the only change I see possible is CO2 moves from 0.000398 fraction of the air to a 0.000598 fraction that will affect the ‘n’ and the ‘P’ very slightly. The pressure (P) would increase to 101345 and the ‘n’ number of moles per kg should decrease to 42.29. Rerun the calc:

101345[P] * 1[V] / 8.31451[R] / 42.29[n] = 288.22 K mean surface temperature.

Me, personally, am not worried about that 0.12 ºC possible increase.

66. davidmhoffer says:

tallbloke says:
February 23, 2012 at 12:13 am
Joel seems to have shifted from trying to defend the radiative greenhouse theory to attacking N&Z’s theory (using inappropriate formulations relative to their line of argument).>>>

I for one didn’t read it that way. Someone said that N&Z disproves radiation greenhouse theory and Joel said N&Z hasn’t been proven, so cannot be used to disprove something else. As much as I disagree with Joel Shore on…. almost everything… I have to agree with him that N&Z has not yet been proven and hence cannot be used to disprove something else.

I think, BTW, that if you are going to allow Joel a guest post, you should also allow him to respond to the thread directly. I think there is much to be gained by Joel Shore and Robert Brown freely defending their positions. Winning a fight with a guy who has one hand tied to the other ankle really isn’t much of a win.

67. Harry Dale Huffman said:
“There are no competent climate scientists, have been none for 20 years.”

Some may consider your comment a little harsh but in my opinion it highlights the real problem. Fortunately, the incompetence of “Climate Scientists” no longer matters as physicists are speaking up. They can predict planetary surface temperatures with excellent accuracy without invoking Radiative Transfer Equations. They just need the TSI, Stephan-Boltzman, albedos, gas laws and thermodynamics. After that, there are minor effects caused by “GCRs”, “GHGs”, ocean currents etc. It may take a while to nail down the relative importance of the minor factors.

Physicists tell us that the chemical composition of a planet’s atmosphere has little effect if the total mass of the atmosphere is fixed. Your arguments on Venus make perfect sense as there is 100% cloud cover and an atmosphere that is essentially opaque to IR radiation. Earth is a little more complicated but one can still make accurate predictions while ignoring RTEs.

68. tallbloke says:

There’s a lot of ambiguity in Joel’s opening sentence:

“The lapse rate in the troposphere is large because the troposphere is strongly heated from below (by the Earth’s surface, absorbing radiation from the sun and back-radiation from the atmosphere)”

The back radiation from the atmosphere is mostly caused by energy which already left the earth’s surface, thereby cooling it. The earth can’t be heated by something which already cooled it.

This is double accounting.

69. Edim says:

“The back radiation from the atmosphere is mostly caused by energy which already left the earth’s surface, thereby cooling it. The earth can’t be heated by something which already cooled it.

This is double accounting.”

Tallbloke, I disagree. Earth can be warmed by any decrease in the heat loss to space, compared to the case without the decrease.

I am a strong skeptic of CO2-GW in every way, but radiative insulation is possible. In case of the Earth’s atmosphere, which is mostly warmed by convection/evaporation and cooled only by radiative heat transfer, increase in radiative activity of the atmosphere will cool the atmosphere and thereby improve the cooling of the surface.

Atmospheric CO2 might reduce the net radiative cooling at the surface, but that doesn’t mean much. It’s the total energy transfer that counts.

70. tallbloke says:

“Tallbloke, I disagree. Earth can be warmed by any decrease in the heat loss to space, compared to the case without the decrease.”

True, but you still don’t get to count it twice. Otherwise you end up with IPCC re-fried chicken.

71. Edim says:

But I agree that there’s a lot of double accounting of the radiative fluxes in climate “science”. Only net radiation should be taken into account of energy budget.

72. tallbloke says:

73. Edim says:

Yummy! That microwave oven is dangerous though.

74. tallbloke says:

More from Joel:

gallopingcamel says:

Fortunately, the incompetence of “Climate Scientists” no longer matters as physicists are speaking up. They can predict planetary surface temperatures with excellent accuracy without invoking Radiative Transfer Equations.

I don’t see physicists claiming this. I see Nikolov and Zeller claiming this and PhD physicists like myself and Robert Brown, who hold very different views on the larger issue of AGW, both saying that their work is fatally flawed.

Note: Nikolov and Zeller are not physicists. Nikolov got his B.S. and M.S. in Forestry and his PhD. in Forest Ecology ( http://www.fs.fed.us/rm/analytics/staff/nikolov.html ). Karl Zeller got BS’s in civil engineering and meteorology, MS in air pollution and dispersion meteorology, and PhD in Fluid Mechanics and Wind Engineering ( http://www.fs.fed.us/rm/analytics/staff/zeller.html )

tallbloke says:

Joel seems to have shifted from trying to defend the radiative greenhouse theory to attacking N&Z’s theory (using inappropriate formulations relative to their line of argument).

Why might that be?

(1) As you may recall, I did not ask for this thread. I posted this as a comment to one of the threads on N&Z where I was trying to explain why their way of adding convection to a model of the radiative greenhouse effect was wrong. You chose to make a separate thread of it.

(2) It is Stephen Wilde who has prompted this particular line of argument in this thread by making the claim that N&Z’s results somehow follow from the ideal gas law.

tallbloke says:

The back radiation from the atmosphere is mostly caused by energy which already left the earth’s surface, thereby cooling it. The earth can’t be heated by something which already cooled it.

This is double accounting.

Okay, since (once the Federal Reserve has printed it), money is a conserved quantity like energy, let’s see how that would work out. Let’s say your employer pays you \$1000 per week. However, to save money, the employer decides that now he is going to take back \$200 of that at the end of each week. By your reasoning, this doesn’t save him any money on your salary because he cannot gain anything from just getting back money he has already given to you.

As for the oven analogy: It is easy to understand why that is wrong. In the picture shown, there is no heat source. Therefore, the most that the mirror can do is slow the rate of cooling of the turkey, which it will do (hence the use of mirrors in thermos bottles). In the case of the Earth, there is a heat source, the sun, and in fact the steady-state temperature is determined by the balance of what the Earth receives from the sun and what it radiates back into space. So, slowing the rate of cooling, unlike the case of the turkey, can indeed result in a higher steady-state temperature.

A good analogy would be to a house: If the house is very poorly insulated and can only keep the temperature at 15 C on a cold winter day even when it is running all the time, would you refuse to believe you could improve this situation by adding more insulation to the attic and walls?

wayne says:

Since ‘P’, ‘V’, ‘R’, and ‘n’ are averaged constants here on Earth; therefore, the mean temperature is also constant on the average at the surface. Just remember, Joel Shore is no physicist, he is a propagandist.

You can’t just constrain variables like density at will…You have to justify any constraints.

When we teach our students the ideal gas law, along with the equation for the thermal energy of an ideal gas E_th = (3/2)*n*R*T, we have them do an exercise where they consider various scenarios, predict what will happen, and then test it using a simulation of an ideal gas.

One of the scenarios is this: You double the number of particles in the container while keeping the volume and thermal energy constant. What happens to the pressure?

Most of the students reason as follows: pV = nRT, so if n doubles and V stays the same then p doubles. However, when they run the simulation, they find instead that p doesn’t change! Why were they wrong? The reason is that in concluding that p doubled, they implicitly constrained T to remain the same. In fact, since we don’t know what either p of T does, we can’t draw any conclusion from the ideal gas law alone. We have to first consider the equation for thermal energy, from which we conclude that temperature in fact has to be cut in half (since this is the only way that you can double n and yet leave the thermal energy unchanged). Only once you know what happens to T can you figure out what will happen to p.

You are making the same sort of mistake that our students tend to make.

75. tallbloke says:

Joel says:
As for the oven analogy: It is easy to understand why that is wrong. In the picture shown, there is no heat source. Therefore, the most that the mirror can do is slow the rate of cooling of the turkey, which it will do (hence the use of mirrors in thermos bottles). In the case of the Earth, there is a heat source, the sun, and in fact the steady-state temperature is determined by the balance of what the Earth receives from the sun and what it radiates back into space. So, slowing the rate of cooling, unlike the case of the turkey, can indeed result in a higher steady-state temperature.

The heat source is the turkey itself Joel. As long as it is above absiolute zero, it emits radiation. You said the Earth was heated by back-radiation. The IPCC chicken oven demonstrates the fallacy.

Now you say that backradiation slows the rate of cooling in the dynamic situation of the Earth being heated by the Sun and re-emitting radiation to space via tha atmosphere. This is a completely different matter. But no matter, now you are using the correct terminology instead of trying to hoodwink the gullible, we can proceed.

How much more does the upper 100m of ocean impede the exit of energy derived from solar heating compared to the 0.039% of co2 in the atmosphere Joel? Let me give you a couple of whacks with the clue bat to assist you. The top two metres of ocean has the same heat capacity as THE ENTIRE ATMOSPHERE ABOVE IT. And; WATER IS NEARLY OPAQUE TO LONGWAVE RADIATION.
So what is mostly responsible for the ocean being at a higher temperature than 255C Joel?

76. tallbloke says:

More from Joel:

Bob_Fj says:

However, the Trenberth energy balance cartoon, for which you have elsewhere stated (paraphrasing), “the numbers are fine”, gives that ~25% of the heat loss from the surface is via radiation directly to space. The other ~75% surface heat loss is ultimately radiated to space over a wide range of altitudes, not some conceptual gas “surface”. Thus your calculation for surface T based on a lapse rate of ~6.5 C/Km and a “radiative cut-off” at 5 Km is deeply flawed, even if the result pleases your purpose.

Your last sentence does not follow from the two previous one so I don’t understand it…although see below for one thing you might be concerned about.

BTW, the lapse rate average of~6.5 C/Km has some considerable temporal and spatial variations, including dryness, and I find the concept of averaging it to do a meaningful calculation as you propose to be highly controversial, and much the same can be said about average global T.

If one is to describe what is going on in a few paragraphs, as I wanted to do, one necessarily has to talk in terms of average values. However, the actual radiative-convective calculations done in the climate models don’t have to make this same assumption. And, in fact, the whole concept of an “effective radiating layer” is itself a vast simplification of how the radiative part is actually treated. I.e., what one solves is the problem of radiation propagating through the atmosphere and having an absorption rate that is extremely strongly dependent on the wavelength (so-called “line-by-line” radiation codes).

What you have to understand is that behind my 3 paragraph summary are equations and lots and lots of calcuations using those equations. I am summarizing the science in prose. The prose is not the totality of the science itself.

tallbloke says: “However, Joel’s use of the gas law is not itself a disproof of N&Z because it doesn’t address the real dynamic situation of the throughput of solar energy in a gaseous envelope subject to gravity.”

What it does show is that any claim that N&Z or others make that the ideal gas law in any way supports their hypothesis is a claim for which we have absolutely no evidence for at the moment. When they show us how the ideal gas law comes into play, then we can judge for ourselves if they are correct.

tallbloke says: “If you could see the snark Joel can’t resist including in his comments which I edit out before reposting the scientific content, you would know why I am acting as the filter. ”

It is easy to make such claims when you are acting as the filter, since there is no way for anybody else to verify this. Why don’t you let the reader’s see the first comment of mine yesterday that you filtered so they can decide for themselves if it is snarky? For your convenience, I append it again below.

————————-

“you can specify any temperature distribution with height that your heart desires and then determine the pressure as a function of height.” only on Joel world.

I have shown mathematically that the 3 constraints of the Ideal Gas Law, the hydrostatic relation, and a specified surface pressure in no way specify the temperature at the surface or the temperature distribution. So, if by “Joel world”, you mean a word where mathematics holds, then yes.

So why are you trying to use it to refute them when they tell you in their papers that you need to use a dynamic consideration of the situation?

(1) What does “you need to use a dynamic consideration of the situation” mean. Give me an equation, a constraint, anything.

(2) Because they and others are continually making statements claiming that in order for their result to be incorrect, one would have to repeal the Ideal Gas Laws.

Can you show me where they made that claim?

I was responding to Stephen Wilde’s statements here about the ideal gas law: https://tallbloke.wordpress.com/2012/02/21/joel-shore-the-radiative-greenhouse-effect/#comment-18117 But, Ned Nikolov has made similar statements, such as here https://tallbloke.wordpress.com/2012/02/09/nikolov-zeller-reply-eschenbach/#comment-16776

Ned has made even blunter statements to the effect that their theory cannot be wrong unless the ideal gas law is wrong, although I can’t find them at the moment.

tallbloke says: “You said the Earth was heated by back-radiation. The IPCC chicken oven demonstrates the fallacy.”

What I said was, “The lapse rate in the troposphere is large because the troposphere is strongly heated from below (by the Earth’s surface, absorbing radiation from the sun and back-radiation from the atmosphere)”. I suppose that one could quibble abouth the use of the word “heated”. It might be more precise to say that the energy inputs at the Earth’s surface include the radiation from the sun and the back-radiation from the atmosphere.

The temperature of the Earth’s surface is then determined by balancing the inputs and the outputs…and the reason that the word “heated” is not unreasonable is that the surface temperature needed for the outputs to balance the inputs is indeed higher than it would be if there were no back-radiation. On the other hand, one should understand that the net flow of heat once all inputs and outputs are considered is still from the warmer surface to the colder atmosphere.

Physicists try to reserve the term “heat” in the noun form to represent the net energy flow. However, I haven’t really seen any convention that the verb form of “heat” can’t be used as I have used it, although it might be better to avoid it if it were to lead to confusion.

tallbloke says: “But no matter, now you are using the correct terminology instead of trying to hoodwink the gullible, we can proceed.”

Would not the phrase “hoodwink the gullible” be considered the sort of snark that you like to avoid here?

tallbloke says: “How much more does the upper 100m of ocean impede the exit of energy derived from solar heating compared to the 0.039% of co2 in the atmosphere Joel? Let me give you a couple of whacks with the clue bat to assist you. The top two metres of ocean has the same heat capacity as THE ENTIRE ATMOSPHERE ABOVE IT. And; WATER IS NEARLY OPAQUE TO LONGWAVE RADIATION.
So what is mostly responsible for the ocean being at a higher temperature than 255C Joel?”

The radiative or “atmospheric” greenhouse effect is responsible for all of the elevation of surface temperature above 255 K (including that of the surface of the ocean). Geometry matters: The ocean does not cause the same change in surface temperature as IR-absorbing elements in the atmosphere because the important thing is that those elements lie between the surface and space. Those elements can thus allow the Earth’s surface to emit more then 240 W/m^2 while still having the the emission of the Earth as seen from space be 240 W/m^2. The fact that the ocean absorbs IR can’t do this!

The effect of the ocean’s large heat capacity is on the thermal inertia in the system, i.e., it causes the diurnal and seasonal cycles to be smaller than they would be in its absence. It also slows the approach to a new steady-state average surface temperature due to a long-term change in forcing, such as that produced by increasing greenhouse gases.

Because the ocean will make the temperature of the Earth more uniform, it can increase the average temperature from what it would be in its absence while keeping the average power emitted by the surface at 240 W/m^2. However, the highest average temperature you can get for a surface emission of 240 W/m^2 is ~255 K which occurs for a uniform surface temperature distribution.

77. tallbloke says:

Joel Says:
“The ocean does not cause the same change in surface temperature as IR-absorbing elements in the atmosphere because the important thing is that those elements lie between the surface and space. Those elements can thus allow the Earth’s surface to emit more then 240 W/m^2 while still having the the emission of the Earth as seen from space be 240 W/m^2. The fact that the ocean absorbs IR can’t do this!”

The surface of the ocean is on average 2C warmer than the air above. Solar energy passes through the atmosphere relatively unhindered on its way into the top 100m of the ocean, where it deposits most of the energy the earth absorbs. Joel wants me to believe the ocean is heated from the top down by the air. This is not possible, because:
1) All the heat transfer processes are moving energy and heat upwards not downwards. Net radiation ~60W/m^2 upwards. Convection – upwards. Latent heat of vaporisation and the upward buoyancy of water vapour. Coupled with the inability of longwave to penetrate the surface of the ocean beyond its own wavelength the picture is pretty clear.
2) As joel now agrees, backradiation doesn’t heat the surface. He says now that I’ve called him on it that it slows the rate of cooling.
3) The ‘surfaces’ we are interested in are, roughly speaking, the bottom of the well mixed layer in the ocean, and the tropopause. The surface we live at falls between these two. It is at the temperature it is because of the heat retaining effects of liquid water, air and water vapour. Oh, and the 0.039% of the atmosphere that is carbon dioxide. 😉
4) By far the biggest heat retainer of these elements is the liquid water in the ocean. The top two metres of it has a heat capacity equal to the entire atmosphere above it. It is at the temperature that it is because it can’t get rid of solar energy as fast as it acquires it unless it gets up to 288K. At that temperature, the water is able to overcome the effect of atmospheric pressure which sets the evaporation rate, and heat the air sufficiently to cause convection and radiation at a rate suitable for equilibrium to be reached. The ocean heats the air, not the other way round. It’s easy to tell that this is true for two principle reasons. (i) On average the ocean surface is 2C warmer than the air above it. (ii) The global average lower troposphere temperature changes lag behind changes in SST by several months.
5) Joel shares with climate scientists like Ray-Pierre Humbert (I use the term loosely) the delusion that only atmospheric gases with radiative properties can lift the temperature of Earth’s surface above 255K – how wrong they are.

78. Anything is possible says:

If nothing else, Nikolov & Zeller have made a pretty convincing case that the true effective grey-body temperature of the Earth, based on incoming solar radiation alone – ie: without an atmosphere OR oceans is much closer to 155K, than the 255K figure that Joel insists on using. What’s more, they have actual good old-fashioned EMPIRICAL evidence – courtesy of the Lunar diviner programme – to back up their claim.

This, by itself, represents a huge challenge to the traditional greenhouse theory as espoused, not just by Joel Shore, but virtually every climate scientist in the world.

If they want N & Z to “go away” they have to refute this, and explain how measured empirical data showing the Moon to have an average surface temperature of 160-170K can possibly be compatible with the Earth having an effective temperature of 255K, when both bodies are the same distance from the Sun.

So Joel, can you come up with a plausible explanation for this using actual science, as opposed to the usual dismissive arm-waving?

Because, if you can’t, all bets are off……

79. tallbloke says:

AiP, the 255K ‘effective temperature’ is the temperature seen from space, and is the temperature the earth has to radiate at in order to lose the same 240W/m^2 it receives from the Sun. There isn’t any dispute over that, so far as I know. The point that is contentious is that the warmies claim that is the temperature the surface would be at without the warming effect of greenhouse gases.

They have things upside down as usual.

The inaptly named greenhouse gases radiate the heat accumulated by the oceans away from Earth into space. Their primary role is in cooling the planet not warming it. The Sun heats the ocean, the ocean heats the air, the GHG’s help the air lose the heat back to space.

80. RKS says:

tallbloke says:
February 23, 2012 at 6:59 pm>>>>>>>>>>>

An interesting and instructive discussion.

I’m relieved to see I’m not alone in my opinion that the effect of back radiation on surface temperature is insignificant.

I’m still waiting for someone to falsify, as opposed to ‘prove’, N&Z’s theory of pressure induced enhancement of insolation. Which is relevant to the discussion of back radiation.

The discussion on radiation induced ocean temperature is fascinating, and I’m watching the ongoing discussion with interest.

[Reply] We will discuss the strengths and weaknesses of the N&Z theory on the N&Z threads. This thread is for criticism of the ‘radiative greenhouse effect’ as espoused by Joel Shore.

81. RKS says:

RKS says:
February 23, 2012 at 7:29 pm
tallbloke says:
February 23, 2012 at 6:59 pm>>>>>>>>>>>

An interesting and instructive discussion.

I’m relieved to see I’m not alone in my opinion that the effect of back radiation on surface temperature is insignificant.

I’m still waiting for someone to falsify, as opposed to ‘prove’, N&Z’s theory of pressure induced enhancement of insolation. Which is relevant to the discussion of back radiation.

The discussion on radiation induced ocean temperature is fascinating, and I’m watching the ongoing discussion with interest.

[Reply] We will discuss the strengths and weaknesses of the N&Z theory on the N&Z threads. This thread is for criticism of the ‘radiative greenhouse effect’ as espoused by Joel Shore.>>>>

Beg pardon!

Strike out my reference to N&Z and that pretty much covers my personal opinion on the ‘radiative greenhouse effect’

Basically, you’ve said all that needs to be said, by the use of scientific reasoning, to falsify that odd hypothesis that uses the same energy twice.

82. Anything is possible says:

Tallbloke says :

February 23rd at 7:28pm

“AiP, the 255K ‘effective temperature’ is the temperature seen from space, and is the temperature the earth has to radiate at in order to lose the same 240W/m^2 it receives from the Sun.”

Yeah, thanks. Not quite the point I was trying to make though.

Lunar Diviner has measured the surface temperature of the Moon as seen from space as 165-175K (80-90K lower than the effective temperature of the Earth). Since the Moon has no atmosphere or oceans, its surface temperature must also be the temperature it has to radiate at to lose the radiation it receives from the Sun. Yet being the same distance from the Sun, it must surely receive the same 240W/m^2 as the Earth does.

In essence there are now 2 things to explain – the 80-90K difference between the effective temperature of the Earth and the Moon (despite their both receiving the same incoming radiation) and the 33K difference between the effective temperature of the Earth seen from space and the observed surface temperature of the Earth, and greenhouse theory has only ever purported to explain the latter.

This raises a further question in my mind : If Joel is correct and increasing greenhouse gases would cause surface temperatures to rise, it seems counter-intuitive to claim that the “effective temperature” of the Earth, as seen from space would not.

Suppose surface temperatures rose by 5 degrees as a result of an enhanced greenhouse effect. What would be the corresponding rise in the Earth’s temperature as seen from space? If the answer is also 5 degrees, then the difference between the Earth’s effective temperature and surface temperature would remain at 33K, despite increasing greenhouse gases. In essence, greenhouse theory would be simultaneously vindicated and disproved….

Wacky….

83. tallbloke says:

From Joel plus my response:

tallbloke: I don’t know what to say in response to your post except the following – Demonstrate explicitly how it satisfies conservation of energy. That is, tell me how the surface of a planet that is at an average temperature of 288 K can radiate an average of only 240 W/m^2 of radiation (which is what has to happen if the atmosphere is transparent to the radiation from the surface). If you can’t clearly explain that, then you do not have a viable theory for how the Earth can be at 288 K.

It is really as simple as that.

[Reply] Joel, I’m not talking toy planets here, but the real deal.
“The inaptly named greenhouse gases radiate the heat accumulated by the oceans away from Earth into space. Their primary role is in cooling the planet not warming it. The Sun heats the ocean, the ocean heats the air, the GHG’s help the air lose the heat back to space.” – It’s that simple. ‘Back radiation’ is pretty much irrelevant because the gap between the surface and the effective radiating height is not a vacuum, it’s full of troposphere, containing processes which completely overwhelm weakly downwelling IR from a cold surface.

84. tallbloke says:

More from Joel:

Anything as possible says:

“If nothing else, Nikolov & Zeller have made a pretty convincing case that the true effective grey-body temperature of the Earth, based on incoming solar radiation alone – ie: without an atmosphere OR oceans is much closer to 155K, than the 255K figure that Joel insists on using. What’s more, they have actual good old-fashioned EMPIRICAL evidence – courtesy of the Lunar diviner programme – to back up their claim.

This, by itself, represents a huge challenge to the traditional greenhouse theory as espoused, not just by Joel Shore, but virtually every climate scientist in the world.”

Nobody has claimed that the average temperature of the earth, given the fact that it (including its atmosphere) absorbs 240 W/m^2 from the sun (and in the absence of a greenhouse effect), has to be at a surface temperature of 255 K. That is the MAXIMUM average temperature it can have…and is the average temperature it will have if the temperature is uniform.

Holder’s Inequality tells us that there are average temperatures lower than that which still satisfy the condition that the planet’s surface radiates 240 W/m^2. Hence, what Nikolov and Zeller have found is absolutely not new. They get their 155 K figure by considering a planet with a very non-uniform temperature distribution. In particular, they assume that the planet’s surface is in radiative equilibrium at every point in time or space, i.e., that there is no energy storage and there is no energy transfer about the planet. It is an approximation that would be somewhat reasonable only for an airless planet with a solid surface and a slow rotation.

If you read a textbook on these things, such as Ray Pierrehumbert’s textbook, you would find a discussion of the fact that the average temperature can be lower than the standardly-calculated T_sb value (which is calculated by averaging T^4 and then taking the 4th root). In fact, in his book, Ray simply says that for airless planets that have such extremes of temperature, the average temperature is not even really a useful metric and it is more informative to talk about the temperature extremes between night and day.

For a planet like Earth with a relatively uniform temperature distribution (and, yes, the temperature distribution is pretty uniform on an absolute temperature scale), discussing the average temperature is much more meaningful because the difference between the average temperature and the fourth root of the average of T^4 is very small.

Anything is possible says:

“Suppose surface temperatures rose by 5 degrees as a result of an enhanced greenhouse effect. What would be the corresponding rise in the Earth’s temperature as seen from space? If the answer is also 5 degrees, then the difference between the Earth’s effective temperature and surface temperature would remain at 33K, despite increasing greenhouse gases. In essence, greenhouse theory would be simultaneously vindicated and disproved….

Wacky….”

The effective temperature as seen from space is set by the radiative balance condition that the planet has to be emitting back out into space the same amount of energy as it is absorbing from the sun. (If it isn’t, it will warm up or cool down until it is.) Hence, what you described won’t happen: The addition of greenhouse gases will, once the Earth has re-attained radiative balance, result in the same effective temperature as seen from space as the Earth had before but with a higher surface temperature. [This is assuming that all of this happens with no change in albedo; if albedo changes, then the amount of energy absorbed from the sun changes. That is why what happens to clouds in a warming world is the one really legitimate question and where the real scientific community, including the skeptics like Spencer and Lindzen, are focussing their attention.]

85. Stephen Wilde says:

“which is what has to happen if the atmosphere is transparent to the radiation from the surface.”

Name one planet with that toytown setup.

The distribution of matter in the universe ensures that no atmosphere is transparent.

Even if it were possible (which it isn’t) then on a spinning sphere under a single sun there would be plenty of turbulence caused by temperature differentials to ensure that the circulation of the atmosphere would configure itself to arrange that an equilibrium could be reached with an emission altitude at the surface relying on conduction, convection and lateral winds alone.

A planet with an atmosphere never, ever has a surface temperature that accords with the S-B equations if the surface is taken as at any point below top of atmosphere.

I don’t have to prove that. It is up to Joel to find one.

When he finds one he will have falsified the Gas Laws.

A planet that cannot configure the atmospheric circulation to obey the Gas Laws will have no atmosphere because it will either boil off into space or freeze on the surface and then in due course be sublimated to space.

In fact such a planet could never acquire an atmosphere in the first place. The acquisition of an atmosphere is dependent on the Gas Laws and a degree of non transparency.

It is that non transparency that enables the gases to acquire sufficient energy from solar input to drive a circulation. Only with a circulation can the gases be retained within a gravitational field.

A transparent atmosphere is impossible. A contradiction in terms. A nonsense.

86. Stephen Wilde says:

Joel said:

“That is why what happens to clouds in a warming world is the one really legitimate question and where the real scientific community, including the skeptics like Spencer and Lindzen, are focussing their attention”

Does that mean, Joel, that you and the ‘real’ scientific community accept that albedo changes could be a negative system response to the increase in GHGs ?

How else could that be ‘the one really legitimate question’ ?

87. Bob_FJ says:

Re: More from Joel posted by TB @ February 23, 6:26 pm

[Bob_FJ]: …However, the Trenberth energy balance cartoon, for which you have elsewhere stated (paraphrasing), “the numbers are fine”, gives that ~25% of the heat loss from the surface is via radiation directly to space. The other ~75% surface heat loss is ultimately radiated to space over a wide range of altitudes, not some conceptual gas “surface”. Thus your calculation for surface T based on a lapse rate of ~6.5 C/Km and a “radiative cut-off” at 5 Km is deeply flawed, even if the result pleases your purpose.
[Joel]: Your last sentence does not follow from the two previous one so I don’t understand it…

You no understand? Oh well, I’ll try to elaborate:
You calculated the surface temperature back from your atmospheric effective radiative surface (let’s call it ERS), at an altitude of about 5 Km, using a lapse rate of ~6.5 C/Km. However, there is no such surface in the atmosphere, it being an imaginary concept, somewhat like effective radiative temperature which has some consideration when viewing Earth from outer space. You have previously agreed that ~25% of the heat loss from the surface escapes directly to space as radiation but of course it has no knowledge of the ERS. The remaining ~75% of surface heat loss, including thermals and evapotranspiration escapes as radiation over a wide range of altitudes that again have no awareness of the ERS. Thus to set an altitude that is about halfway up the troposphere (and its lapse rate) and then calculate from there back to give the surface temperature seems to be a bit strange and perhaps even “cart before the horse”.

I also find it smile producing that using the average lapse rate of ~6.5 C/Km, and an ERS of 5 Km, (not say 5.1 or 4.90 or 5.001), that you end up with 287.5 K, within half a degree of the desired 288K. How did you obtain exactly 5 Km.? Maybe from your favorite book of Raymond Pierre’ that you keep under your pillow? BTW, Dry lapse rate can be ~10 C/Km.

[Joel]: ….although see below for one thing you might be concerned about.

Actually I made a “BTW COMMENT” that showed additional issues but asked you not to comment on them. (because it would be distracting to add a complex discussion to the relatively simple main issues above).

88. Markus Fitzhenry says:

‘FJ says
I also find it smile producing that using the average lapse rate of ~6.5 C/Km, and an ERS of 5 Km, (not say 5.1 or 4.90 or 5.001), that you end up with 287.5 K, within half a degree of the desired 288K. How did you obtain exactly 5 Km.? Maybe from your favorite book of Raymond Pierre’ that you keep under your pillow? BTW, Dry lapse rate can be ~10 C/Km.’

Click to access 1981_Hansen_etal.pdf

My reading of it the ERS could also have been at a altitude of 6klms. Hansen tortured the equation and obtained the Lapse Rate by reverse architecture.

89. tallbloke says:

OK, we’ve reached the usual point in discussions with Joel where he has a fog of incomprehension when it is pointed out that the ocean drives the atmosphere rather than the other way round. Past experience of debating with Joel has taught me that attempting to get any further useful debate after this point is a waste of time and a cause of frustration. Maybe it’s a genuine inability to see past the narrow confines of his radiative-centric physics education rather than a deliberate obfuscation – who knows.

I’ll be closing comments on this thread for ten days while I’m away, so I suggest anyone who wants to make a summarising statement does so before 6pm GMT this evening.

90. wayne says:

So what have I learned on this thread… basically zip…. well, that Joel teaches his students that if you have one square meter of air on the surface of the earth and know accurately the pressure, density and molar mass (therefore number of particles, n), and the gas constant you cannot by him know temperature by PV=nRT or T = PV/(nR). Above I use that and get 288.1K, seems pretty accurate to me. Oh… his poor students.

And yes Joel, I do know in that case if the temperature is different the density will change proportionally… or vise-versa.

And I hope everyone will learn by studying above, where Joel disagreed with my “out-of-context sentence”, a little of his MO and not let him lead you astray.

91. wayne says:

What I learned on this thread from Joel Shore that is.

92. tallbloke says:

Wayne: let Joel get away with the out of context quote without comment because I knew you could handle it yourself. 🙂

93. Tenuc says:

My take from this thread is that Joel fails to see the problems that are caused by applying SB equations at the surface at the surface of Earth, rather than at TOA. Processes below the tropopause are governed by water (in all it’s forms) and atmospheric density, with down welling IR having little or no effect.

He also seems to think that using averages to calculate the behaviour of our dynamic non-linear climate system is acceptable, which I find difficult to understand, coming from a physicist.

He seems to me to be more of an advocate AGW, rather than a sceptical scientist who is seeking the truth.

94. tallbloke says:

More from Joel plus a summary:
@Bob_FJ: Bob, I have explained to you that if you don’t want to use averages, you don’t have to.The detailed models don’t. As for the average environmental lapse rate of 6.5 C per km, here is a discussion of it: “As an average, the International Civil Aviation Organization (ICAO) defines an international standard atmosphere (ISA) with a temperature lapse rate of 6.49 K(°C)/1,000 m[citation needed] (3.56 °F or 1.98 K(°C)/1,000 Ft) from sea level to 11 km (36,090 ft).” [http://en.wikipedia.org/wiki/Lapse_rate ]

wayne says:

“Well, that Joel teaches his students that if you have one square meter of air on the surface of the earth and know accurately the pressure, density and molar mass (therefore number of particles, n), and the gas constant you cannot by him know temperature by PV=nRT or T = PV/(nR).”

You don’t know the density, Wayne, unless you constrain it not to change, which you have no physical justification for doing.

Stephen Wilde says:

“Does that mean, Joel, that you and the ‘real’ scientific community accept that albedo changes could be a negative system response to the increase in GHGs ?

How else could that be ‘the one really legitimate question’ ?”

Yes. Stephen, it is possible. I don’t think the empirical evidence supports it [snip]

To summarize, you can come up with all sorts of mechanisms for the surface temperature to be above 255 K if you don’t require yourself to explicitly show how your mechanism still satisfies conservation of energy, i.e., how it is still compatible with the Earth emitting an average of only 240 W/m^2 as seen from space. It is coming up with mechanisms that you can explicitly show satisfy conservation of energy that is the hard part.

95. Stephen Wilde says:

“It is coming up with mechanisms that you can explicitly show satisfy conservation of energy that is the hard part”

Joel, you keep saying that but I don’t see it.

The ‘discrepancy’ that you keep referring to can be easily dealt with by a dynamic energy exchange between surface and air which leaves enough left over for the top of atmosphere to be radiating out at the same rate the sun is putting energy in.

I see the radiative GHG theory as the real breach of conservation of energy because on that account more GHGs beget more GHGs via water vapour amplification then more warming as a result then more amplification ad infinitum. That doesn’t make sense. On that basis one molecule of CO2 or another non condensing GHG would have blown the atmosphere off into space shortly after the birth of the Earth.

Can AGW theory explicitly satisfy conservation of energy ?