Bishop Hill Great Evans above
Sep 26, 2015 Climate: Models Jo Nova carries a rather interesting piece today about some work done by her husband David Evans, who thinks he has uncovered a rather major flaw in the mathematics at the core of the basic model of the climate.
The climate models, it turns out, have 95% certainty but are based on partial derivatives of dependent variables with 0% certitude, and that’s a No No. Let me explain: effectively climate models model a hypothetical world where all things freeze in a constant state while one factor doubles. But in the real world, many variables are changing simultaneously and the rules are different.
Partial differentials of dependent variables is a wildcard — it may produce an OK estimate sometimes, but other times it produces nonsense, and ominously, there is effectively no way to test. If the climate models predicted the climate, we’d know they got away with it. They didn’t, but we can’t say if they failed because of a partial derivative. It could have been something else. We just know it’s bad practice.
This sounds plausible to me. What do readers here think?
Reader Comments (199)
Ouch, Rhoda! Yep, you definitely are NOT as ignorant as I. I suspect you will need no help wiping the floor with any opposition.
David Appell: should you read the work of Mr Huffman, you will find that he shows that albedo has nothing to do with it, thus it can be ignored, as it is IRRELEVANT! This is not actually a new idea, as there have been others (sorry, their names escape me at the mo – but they are not unknowns) who have postulated what Mr Huffman says.
I found this in part 6 of David Evans' series.
"CO2 is a slightly heavier molecule than N2 or O2, so it tends to settles to the bottom of the atmosphere. "
Oh dear!
EM!
Dear EM you posted something I can agree with hehe
Dung, EM,
You both must be wrong: (carefully selected) "basic physics" says Evans is right.
Robert Swan
Would that be the 'basic physics' as described by a certain Prof Bob Watson ^.^
I left David Evans a long comment on why his objections to the standard theory of climate science may be wrong. It may be of interest to readers here.
David: I read your posts with interest, but suspect you may have the basic situation wrong. GCMs don't calculate radiative fluxes and feedbacks from partial derivatives. The output from GCM's and/or observations can be analyzed to determine such ratios and "explain" climate change in terms of forcing and feedback.
More importantly, we are interested in the SIMPLE DERIVATIVE of net inward radiative flux (G) with surface temperature (T) - dG/dT - NOT the partial derivative - pdG/pdT. The simple derivative tells us how much the surface of the planet needs to warm or cool to eliminate a given radiative imbalance. This ratio is called the climate feedback parameter and its reciprocal is ECS. If we know ECS, we have a theory of AGW. The simple derivative is ALL we need for a theory of AGW, but climate scientists have tried to explain factors that contribute to dG/dT as shown below. These factors are poorly understood, which why is why the IPCC reports a 15-85% ci for ECS (for 2XCO2) of 1.5-4.5 degC. This uncertainty doesn't invalidate any theory of climate change - it simply makes it impossible to use the theory to make USEFUL predictions about the future. Climate models don't tell us what ECS for the real planet must be, nor do they usefully constrain the possible range of ECS. Ensembles of simple models with only six perturbed parameters give values of ECS ranging from 1 to 11 degC. (Stainforth, 2005)
pdG/pdT is the reciprocal of the no-feedbacks climate sensitivity. If there were no feedbacks and if the planet acted as if it were a homogeneous blackbody at 255 degK (the temperature needed to balance 240 W/m2 of incoming post-albedo SWR), then the S-B eqn allows us to calculate that pdG/pdT is -3.2 W/m2/K. As you note, the real world doesn't act this way, but our knowledge of blackbody radiation allows us to predict what would happen under this scenario.
Climate sciences sometimes calculates dG/dT using the following equation with partial derivatives, where H is humidity, L is lapse rate, C is clouds and I is snow and ice on the surface of the planet. In some of these terms, G is only SWR (G_SWR) or only LWR (G_LWR), but I have omitted this for simplicity. Remember, this equation isn't a fundamental part of climate theory. Only dG/dT is.
dG/dT = pdG/pdT + (pdG/pdH)*(pdH/pdT) + (pdG/pdL)*(pdL/pdH)*(pdH/pdT) +
(pdG/pdC)*(pdC/pdT) + (pdG/pdI)*(pdI/pdT)
We believe we have a fair idea of what some of these terms should be and we can abstract average values for all of them from the output of GCMs. For example, absolute humidity at equilibrium rises about 7% per degC, so the same percentage rise in humidity is often assumed to occur everywhere - even though water vapor in the atmosphere is far from equilibrium in many places. This produces a value for pdH/pdT.
GMST rises about 3.5 degC (before taking anomalies) every year because the NH has a lower surface heat capacity than the SH. Satellites measure seasonal dG (and dT for SST) and separate LWR from SWR and clear skies from cloudy skies. The planet as a whole emits about 8 W/m2 of LWR through clear skies when GMST is 3.5 degC warmer (-2.3 W/m2/K). Since clouds and surface albedo aren't relevant to emission of LWR through clear skies:
dG/dT = pdG/pdT + (pdG/pdH)*(pdH/pdT) + (pdG/pdL)*(pdL/pdH)*(pdH/pdT)
-2.3 W/m2/K = -3.2 W/m2/K + 0.9 W/m2/K
From this we can conclude that the combined water vapor and lapse rate feedback is about +0.9 W/m2/K (for seasonal, but not necessarily global warming). A similar value can be obtained for both seasonal and global warming using climate models and they tell us the lapse rate term is about -1 W/m2/K and that the direct reduction of G is about +2 W/m2/K due to absorption and emission of LWR by water vapor. The models do a poor and inconsistent job of predicting the observed seasonal changes in SWR reflected from the surface through clear skies (seasonal snow albedo feedback) and both LWR and reflected SWR from cloudy skies. Therefore, there is no reason to assume that GCMs will accurately predict feedbacks from during GHG-mediated global warming. The only feedback that is too slow for seasonal warming is the albedo feedback from melting glaciers. For more see Manabe (2013):
http://www.pnas.org/content/110/19/7568.full.pdf
I cite this information merely to demonstrate that the partial derivatives that describe feedbacks have some basis in reality. On average, they have a reproducible value for the planet as a whole during seasonal warming. That makes them different from the examples you cite where a partial derivative can have multiple values (or is indeterminate).
(The planetary response dG/dT is produced by the response in dG/dT at all locations on the planet. Different amounts of warming in different locations can produce a different dG/dT for the whole planet.)
Whenever someone asserts that 240w/m2 equates to 255K my BS alarm goes off. The relationship relies on so much 'idealisation' that it is useless. If your chain of logic starts from there it won't drag much of an argument behind it.
Rhoda asked: "Are there any testable intermediate results [from climate models] which we could use to determine the validity of the models."
Yes and no. To the extent that AOGCMs are similar to weather prediction models, we know that a properly initialized model will usual predict the state of the atmosphere fairly accurately about a week in the future and show no skill several weeks in the future. This is because weather is chaotic and the output of chaotic systems varies unpredictably and radically when initialization conditions are changed very slightly. There are also problems created by the need for parameters to describe sub-grid processes.
With climate models, we assume that the errors that develop several weeks after the model is started average out over the decade+ periods that define a climate and over several different initializations. We can compare model climate with current climate. Some things are fairly accurate. Some are not. The question is whether such models are fit for the purposes they are used for.
Dung,
Not Watson in particular, but he fits. There are any number of people who beat us over the head with "basic physics". It's quite a paradox that many of the people who say it's so basic promote the spending of millions building and running complicated computer models.
Frank, Thanks for that well thought out response. You say this
'...We believe we have a fair idea of what some of these terms should be and we can abstract average values for all of them from the output of GCMs…."
but then go on to say that the GCM's leave a lot to be desired. Is that somewhat circular?
The question it seems to me and I would be interested to read your opinion is what level of modeling is more likely to be an accurate representative of a non stationary system with a huge range of important scales from the planetary scale to the microscopic turbulence of the boundary layer. We know that energy is conserved overall and so simple models are based on a true conservation law. However, they have some very simplified feedback parameters that must be constrained with data. However, GCM's try to include more physics, albeit on a very course spatial grid so the numerical truncation error is large and try to parameterize things like tropical convection. Held has a nice post showing that this may be impossible to do with real accuracy, so there are all kinds of errors that are hard to constrain with data, which at the detailed level may be very inaccurate. And then there are intermediate complexity models.
Thoughts? My position I've stated before and won't rehash here.
My reply to Frank's comment (Sep 29, 2015 at 11:58 PM above, also left at JoNova) is here.
Robert Swan,
"There are any number of people who beat us over the head with "basic physics"."
Showing that the basic physics is wrong is a necessary, but not sufficient, condition to win the AGW argument.
Skeptics have mainly queried the parameter values in the basic physics -- there are basically only three:
- Decrease in OLR if CO2 doubles, all else constant. Based on lab spectroscopic results, probably about right.
- Planck sensitivity (reciprocal of Planck feedback, whatever). Just Stefan-Boltzmann, modified by 20% mainly for non-SB behavior of stratospheric CO2, cannot be too far wrong.
- Feedbacks to surface warming. Based on solid physics of water vapor and lapse rate, probably ballpark ok.
It is hard to see where there might be a really large error.
I am arguing instead that the "basic physics" has been misapplied. The physics is good, but the climate scientists misapplied it. I claim the architecture of the basic model is wrong, and that some of the erroneous features are also present in the GCM architecture. Unfortunately to substantiate that claim takes several blog posts: first state the basic model used to apply the basic physics, get everyone on same page re certain aspects of basic physics, then show the conventional basic model has errors, fix those errors by building a better model with which to apply the basic physics, then estimating ECS. This series is underway, please be patient as we roll it out.
David,
Unless I've missed it, you appear to not have corrected your mis-representation of me. This may not be all that surprising given that you appear to now be misrepresenting the papers to which you link in your response to Frank on JoNova. Those papers are not presenting partial differential equations that are explicitly solved in climate models, they're presenting equations that could be used to determine things like climate sensitivity and feedbacks from climate models. In a full climate model, these quantities emerge from the model/calculations. You can then determine what they are by how the system responds to various changes, but that doesn't mean that these partial differential equations are actually solved within the model itself. The partial differential equations are also not solved in basic climate models since there is no way that that could be done. In a basic climate model you typically assume that the feedbacks depend linearly on temperature and are known in advance, or you compare with observations to determine what they might be. Unless you can show otherwise, you are presenting a set of partial differential equations that are used to analyse output from complex climate models, while claiming that these are the equations that are solved by climate models.
Frank: one slight flaw in your logic is that you seem to assume that, if there is any change, it is anthropogenic (“If we know ECS, we have a theory of AGW."). Where is your evidence?
I am not sure about the world of the AGW adherents, but in mine, a theory which is verified on at least two planets (Earth and Venus), probably a third (Mars), and possibly others, is considerably more believable than a theory that cannot be verified on one planet.
I suspect I will regret asking this, but what theory has been verified on at least two planets, and maybe third?
A forcing by the way is only necessary to simplify the model. Ideally the only forcings would be the sun, seismic events and planetary wobbles while everything else would be a feedback. Alas that would be unrealistically complex and would take forever to run :)
ATTP
I think that would be the Maxwell theory that the surface temperature of a planet depends only upon surface pressure and radiation received at TOA, at least that's what I remember ^.^ I can not find the link but apparently this theory was validated by our new knowledge of these measurements on more planetary bodies :)
Dung,
Has anyone considered that they may simply have rediscovered the well known property that pressure depends on temperature and density, normally through what is called an equation of state.
ATTP
As they say in the movies "you got me" hehe. I am a poor unqualified peasant sir and not fit to clean your boot but I believe you are probably right ^.^
Dung,
The point is that there is a relationship between pressure, temperature and density which is essentially
P = rho k T/m
where rho is the density, k is Boltzmann's constant, and m is the mean mass per gas particle.
What some seem to be suggesting is that the high temperatures are a consequence of the high pressures. Well, why are they high? If we have a high temperature we would expect - for a given density - a high pressure. What's keeping the pressure high? Why doesn't it simply cool, allowing both the pressure and temperature to drop? The reason is what is typically called "the Greenhouse effect".
David: Manabe (2013, PNAS) shows that current models don't reproduce the feedbacks observed from space in clear vs cloudy skies and SWR vs LWR channels during seasonal warming and cooling. Moreover the models disagree with each other substantially. So I conclude that the partial derivatives describing feedbacks are real, but highly uncertain. Therefore ECS is highly uncertain.
Manabe is one of the founders of the GFDL model and may have initiated collection of seasonal data from CMIP models. He has quantified how well/poorly the models reproduce the seasonal cycle, but judiciously draws no conclusions about the significance of discrepancies, except that the information might be used to improve models. I presume he is looking for parameters for the GFDL model hat reproduce the seasonal cycle better. Whether such parameterization can be found using current grid cell size is unknown.
As they say, all models are wrong, but some are useful. Judith Curry has discussed the "useful for what" issue. IMO, the range of ECS exhibited by the IPCCs models doesn't properly constrain ECS, so the range of model predictions about the future is meaningless. The range of future predictions should depend on our knowledge of ECS and TCR which is +/-50% for 15-85% ci. So if a future modeled scenario predicts a central estimate of 2 degC of warming, the ci should be 1-3 degC for models with no central estimate because AOGCMs and energy balance models disagree.
Dung: you should not put yourself down; others will be more than happy to do that job for you.
You are right, though I didn’t know it was known as the “Maxwell Theory”. Other, greater minds have followed the idea (none of which spring to mind, and I cannot find the site where they are mentioned); what appeals to me is that it works, which is something that the theory of “greenhouse effect” does not. While it is obvious that the atmosphere does have some effect upon average temperatures, mainly by moderating the two possible extremes of daytime and night-time, perhaps the term “greenhouse effect” is rather a misnomer… but, then, I have no ideas for an alternative term.
In what way does it work?
The point of this is that it is not dependent upon what gases are involved and works regardless of whether greenhouse gases are present or not. Feynman was impressed and so why should I not be?
Dung,
The equation of state doesn't really depend on the gases (well, it does a little because of the mass of the actual gases) but what it cannot explain is how a planet like Venus (which is only 30% closer to the Sun than the Earth) can have a surface temperature 500K higher than the Earth's.
I also suspect that whoever is suggesting the Feynman may be impressed by this, may be misrepresenting Feynman.
I am going to have to stop discussing this until I find my references. What I remember reading is that back in the 19th century Arrhenius and Maxwell came up with competing theories about how planetary temperature could be calculated. The Maxwell theory stated that greenhouse gases were not required in the calculation, recently on BH it was reported that Maxwell's theory had been validated but I can not find that thread :(
Yes, Dung – the atmosphere of Venus is about 96% CO2, yet, at an altitude where the atmospheric pressure is that of Earth’s, the temperature is about 66°C – which is roughly what the Earth’s surface temperature would be, if it was as close to the Sun as Venus (bearing in mind the inverse squared law, etc., etc.). Should ECS be a reality, then, with 96% being over 11 “doublings” from 0.04%, the temperatures should be at least 77°C (or >154°C, which covers much of the range of claimed ECS). The theory continues to hold, even down at the surface, where the pressure is about 92 times that of Earth’s surface pressure, giving a surface temperature about 445K above Earth’s. As well as on Earth, it also applies on Mars, another high-CO2 atmosphere, where the temperatures are comparable to what they would be on Earth, at similar pressures and distance from the Sun. I don’t know if they have the necessary data from other bodies.
Yes, I think Feynman was one of those impressed by the theory; that he doesn’t discount it out of hand does imply that there could be something in it. He was not the only one – I just wish I had noted the site where I found this information.
RR,
You still haven't explained the theory. There is a relationship between pressure and temperature. That the temperature in Venus's atmosphere, where the pressure is the same as that at the base of the Earth's atmosphere, is the same as on the Earth is no great surprise. How does your "theory" explain why the surface temperature and pressue on Venus is so much greater than on Earth?
Have a look here. All the numbers and calculations are there – and no, it is not “my” theory; I shall let others take that accolade. Oh, and while it does nothing to explain the surface pressure, it does take the pressure as a factor in the temperature.
RR,
Yes, I saw that. None of that, however, tells me why Venus's surface has such a high temperature and pressure relative to the Earth. Why doesn't it simply cool. If it did, the temperature would go down, but so would the pressure. It would still probably satisfy the pressure - temperature relation in that post. That there is a relationship between pressure and temperature is no surprise. What your "theory" needs to explain is why they have the values that they have, not that there is a relationship between them. So - again - how does your theory explain the actual temperatures and pressures on Venus?
Well, if you cannot understand what is being said on that site, with its very detailed explanations, there is probably little I can do to help clarify it for you. Sorry.
David Evans,
That's backwards isn't it? It would be sufficient, but not necessary. That's how I see it at least.
I applaud your tenacity; you have been trying to help develop a better model (and getting little enough thanks from either side). Good on you for that.
I am lazier and less generous. I don't have the knowledge to build a plausible model but, having a mathematics background, I do know enough to understand the sorts of things Steve McIntyre highlights. Those on top of various intuitions, and my predisposition to cynicism and here I am, boldly rejecting "the science", even in the face of the 97%!
The "basic physics" thing is just a hot button for me. Basic physics distills away all the complexities of the real world to arrive at fundamental principles. The weather system puts all the complexities back in and basic physics goes out the window. An omelette can be reduced to your basic egg, but starting with eggs, you can end up with custard just as easily as an omelette. Or, as with climate modelling, you can end up with a stinking mess.
ATTP,
In your conversation with RR you said:
'What your "theory" needs to explain is why they have the values that they have'.
Why? A religious question? Has anyone been able to explain why F = ma?
Perhaps you've moved from physics to metaphysics.
RR,
I do understand what's being said on that site. Nothing on that site explains WHY the temperature and pressure on the surface of Venus is so much higher than on Earth. That you either don't see this yourself, or do but will bluster your way out of admitting it, is no great surprise.
While I cannot explain why the surface atmospheric pressure on Venus is 92x that of Earth’s for a body about the same size, this is a bit of a straw man, so I shall leave that to planetologists (or whatever) to decide, and I can accept that it is. As for the temperature, this is determined by two principle factors – the atmospheric pressure, and the incoming energy from the Sun. What causes the surface pressure to be what it is, and the components of the atmosphere are irrelevant; the key is that the temperatures at the surface, or, indeed, at any other level in the atmosphere, are determined by the atmospheric pressure and the amount of incoming radiation – i.e. the body’s distance from the Sun. This has been verified on Earth and Venus, and, possibly, Mars. As this is explained in considerably more detail in HDH’s article, yet in such a way that even I can understand it, this can only lead me to one of two conclusions: 1) you have not read the article, or 2) you really are thick. I know which of those I prefer, but which is it, really?
RR,
Most people write the equation of state as
P = (rho k T)/m
for a reason. The pressure is set by the density of the material and its temperature, which is a measure of the average energy per particle. If you want to argue that the temperature is set by the pressure then you need to explain why the pressure is itself so high. That's the bit you haven't done.
In the absence of a greenhouse effect, a planet with a surface temperature like that of Venus, a similar distance to a star like the Sun will be losing more energy than it is gaining. Since temperature is the average energy per particle, this means that the temperature will go down. If the temperature goes down, so does the pressure. What is stopping this from happening on Venus?
Radical Rodent: The existence of a lapse rate can be explained by buoyancy driven convection (the rxplanation found in textbooks) or by thermogravity. The existence of lapse rates that agree with either explanation can not validate thermogravity. If thermogravity were correct, heat would spontaneous flow from cold to hot in an isolated vertical column of gas in a gravitational field. That violates the 2LoT. Gas molecules transfer kinetic energy by collisions much faster than they convert it to potential energy. No gas molecule ever travels 1 km upward and cools off 6.5 degK unless ir is convected upward as part of an large group of molecules. Advocates of thermogravity focus only on the exchange of kinetic and potential energy and ignore the collisions that rapidly transfer kinetic energy to molecules that have lost klneric energy by rising. A trivial amount of kinetic energy given a mean free path of um!
If we know how much more radiation escapes to space after one degK of surface warming (dG/dT), then we know how much warming must occur before a GHG induced imbalance is corrected.
If you can take a calculator on a trip to Venus, Mars and certain moons of planets you can calculate surface temp from TOA radiation measurement and surface pressure. That is now validated so why look at equations to justify it?
aTTP: perhaps you can tell us why the Earth’s surface pressure is what it is, or why Mars' atmospheric pressure is so low? How does the atmosphere of Ganymede compare? I cannot tell you why – I cannot even make a guess why – the surface pressure on Venus is so high – but it is a strawman argument. I cannot explain gravity or magnetism, but that does not invalidate their existence. Yes, the absence of an atmosphere would mean that day-time temperatures are extremely high, while the night-time temperatures are extremely low; this can be seen on the Moon. However, as can be seen on Venus (and Mars), the constitution of the atmosphere appears to have no part in its average temperature; both are what Earth’s temperatures would be if in a similar orbit and with similar pressures, even though the composition of the atmospheres is very different; the point is that it is the atmospheric pressure and the distance from the Sun which seem to be the key elements to the atmospheric temperatures. In other words, the “greenhouse effect” – by which I mean the arrestment of energy in its radiation to space from Earth’s atmosphere by elements of that atmosphere, in the same way that the glass of a greenhouse stops (or slows) the radiation of heat from within – is completely wrong, or a faulty explanation or a sloppily-applied term.
Frank: there are basically two lapse rates: the adiabatic lapse rate (ALR), which is the cooling of a parcel of air as it rises, and the environment lapse rate (ELR), which is the reduction in temperature of the atmosphere with increasing altitude. While the ALR requires air movement, the ELR requires none (and, it could be argued, is further validation of Maxwell’s theory (a name proffered by Dung, and I see no cause to argue the convenience of its further use)). Generally, the ALR is lower than the ELR, thus the parcel of air continue to rise until a balance is reached; if the ALR exceeds the ELR, thermal inversion occurs, which can be seen most dramatically when rising smoke flattens out.
Dung,
Because that does not explain why the pressure is what it is. The reason the pressures are what they are is because of the temperature and density. As Frank has pointed out, the temperature profile in an atmosphere is set by convection. This sets what is called the lapse rate. Greenhouse gases prevent all of the energy from being radiated directly from the surface to space. Some of it is radiated from within the atmosphere itself. This means that the effective emission height is not on the surface, but is somewhere in the atmosphere (h > 0). Given that convection sets the temperature profile, and since this is negative (i.e., temperature goes down with increasing height), the surface temperature must be higher than the temperature at this effective emission height. The temperture at the effective emission height is set by the balance between the incoming and outgoing energy. Therefore the surface temperature is higher than it would be in the absence of an atmosphere. This is what is often called the Greenhouse Effect. The density profile in the atmosphere is then set by hydrostatic balance. The pressure then comes from the relationship between density and temperature. You can't simply invert this and claim that the temperature comes from the high pressure because that fails to explain why the pressure is high in the first place.
RR,
I think my previous comment essentially does what you ask. Also, your distinction between ALR and ELR is essentially wrong. The ALR is essentially what we would expect if we had a nice uniform atmosphere with no water vapour, or a constant distribution of water vapour. The ELR is simply the lapse rate at a particular time and place. It doesn't obey different laws of physics, it simply represents that in the real world the actual lapse rate at a particular time and location may not match we would expect theoretically in a simple, idealised world.
As far as I am concerned the why question is an irrelevant distraction however interested you might be in the so called science.
What I (and the rest of the population) need to know is whether or not CO2 really is responsible for dangerous warming. This work by Maxwell (and no doubt others) was done in the late 19th and early 20th century but only recently has it been possible to check it against empirical evidence. We are now told that empirical evidence has validated the original theory and also by default it proves the Arrhenius theory wrong.
'the reason the pressures are what they are is because of the temperature and density.'
No the pressure comes from the amount of atmosphere. Its weight.
Also, the temperature profile of an atmosphere is NOT set by convection; my distinction between ALR and ELR is essentially RIGHT. The ALR is the rate of cooling of a parcel of air as it rises in the atmosphere; the “adiabatic” part of the phrase is another way of saying certeris paribus or “all else being held equal”; it is, in effect, the air cooling as its pressure drops. I have a feeling that there is a law about that, somewhere. The ELR is the rate of cooling of the ENVIRONMENT (you see, that is what the “environment” part of “environment lapse rate” is referring to) with altitude, movement of air within it being irrelevant to the figure; thus, when the ALR is lower than the ELR, the parcel of air will continue to rise, until equilibrium is reached (which will happen because not all things actually are held equal, but are too variable to enumerate). Should the air parcel reach its dew point, the water vapour in the parcel will start to condense out, and the lapse rate is then termed “saturated adiabatic lapse rate” (SALR – it is can also be known “Wet ALR” or “Moist ALR”), which is about half the dry ALR.
RR,
Hmm, yes, you're kind of right about that one. The pressure is indeed set by the mass, the density is then set by the pressure and the temperature (I've been teaching about stars which don't have big lumps of rock in the middle). However, what you have yet to explain is how the surface of a planet can radiate much more energy than it is receiving without cooling. Why don't you try and explain that before calling other people stupid, especially as you appear to be denying the Greenhouse effect; even amongst people who reject most of mainstream climate science that is regarded as pretty damn stupid.
Huh? What you then describe pretty much appears to be convection. You do realise that convection is really just the bouyant rise of gas parcels? In a simple sense, if the temperature gradient is steeper than the lapse rate, then its convectively unstable, and convection returns the profile back towards the lapse rate. If it is shallower than the lapse rate, it is stable, but energy transport is inefficient, and it will warm from the surface and steepen back towards the lapse rate. The enviromental lapse rate simply refers to the fact that the atmosphere is much more complex than this simple calculation and so there can be regions where the actual temperature profile is different to what you'd expect based on a basic lapse rate calculation.
I might have misunderstood your point; perhaps I should have said the temperature profile of an atmosphere is not only set by convection – there are a lot of complex mechanics at work. Start with an atmosphere with no air movement; its ELR can then be established (which is what I thought you meant by temperature profile); now, add the rising parcels of warm air, and the similarly sinking parcels of cool air; put a spin on the planet, and the resultant air flow so caused; now, add a variable planetary surface, and its effects on the air movement. The temperature profile then becomes a complex, variable factor, with little “setting” being established, though there may be a degree of regional uniformity. The ELR is the rate at which a column of air cools with altitude, with no movement in that column; there is a generally accepted ELR, but it is known that this can be affected by various local factors, most commonly causing thermal inversion, when the column has a vertical section that does not cool with altitude.
RR: The ELR (environmental lapse rate) is what we observe - the product of dynamic covection, radiative transfer of heat, molecular collisions and molecular diffusion. Observation of complicated planetary atmospheres can NOT tell us anything about what lapse rate would exist if convection and other complications did not exist. Fundamental physics allows us to calculate DALR and MALR and recognize that any atmosphere with an ELR higher than these theoretical LRs will be unstable to buoyancy-driven convection.
The advocates of thermogravity believe that molecular diffusion will spontaneously produce a lapse rate of g/Cp in the absence of all other complicating factors. They are correct. However, they ignore molecular collisions, which are responsible for the transfer of heat from hot to cold and the 2LoT. In any real gas, you can't have molecular diffusion without molecular collisions and the 2LoT. In solids, we have molecular collisions and thermal conductivity with negligible molecular diffusion. In gases, we have both.
In the troposphere, molecules travel only 0.1 to 1 um between collisions at a speed of about 400 m/s, and collide 10^6 to 10^10 times per second. Under these conditions, it is absurd to expect a temperature gradient to develop because a minuscule amount of kinetic energy may be converted potential energy between collisions. Compare the ratio of kinetic to potential energy involved 1/2mv2 to mgh: about 10,000,000 to 1.
In space half way to the moon, the mean free path of gas molecules might be long enough that a change in potential energy occurs between collisions that is comparable to the kinetic energy of the gas molecule. There a thermogravitational gradient might develop EXCEPT that our concept of temperature is based on the mean kinetic energy of molecules that collide more frequently than they exchange energy by any other process - LTE. So we can not say thermogravity is relevant anywhere.
Venus is complicated.
Some excellent discussion here:-
http://scienceofdoom.com/2010/08/16/convection-venus-thought-experiments-and-tall-rooms-full-of-gas/
HarryDaleHuffman,
Notwithstanding ATTP's best attempts to confuse the situation, the atmospheric pressure at the surface of the planet is determined solely by the total weight of gas in the atmosphere. A lapse rate will always exist in any real atmosphere for some distance above the surface of a planet, outwith sperical cow thought experiments. Assuming a surface temperature and pressure of Ts and Ps, and a lapse rate alpha, the assumption of hydrostatic equilibrium plus ideal gas law yields the following pressure equation at height Z:-
P = Ps * exp[{Mg/(alpha*K)} * Ln ((Ts - alpha*Z)/Ts))]
Z is the height above the surface of the planet and K is the universal gas constant. On Venus, the near-surface lapse rate, alpha, is close to moist adiabatic I understand - although the vapourisation and condensation process is through sulphuric acid rather than water. What all this means is that there are no mysteries here in terms of calculation of temperature and pressure at elevations above Venus GIVEN the surface temperature and pressure and the atmospheric properties.
The big mystery about Venus which as far as I can tell is unexplained with or without GHG theory is why the brightness temperature is far in excess of what we would expect given a simple calculation of the received solar radiation. It is known that Venus does not behave even approximately as a black body, but even at lower wavelengths the theoretical radiating temperature is much higher than we would expect. If anyone really does have a good explanation for this, I would very much appreciate a reference.
To me it sounds rather confused.