Guest Post by Willis Eschenbach
A couple of apparently related theories have been making the rounds lately. One is by Nikolov and Zeller (N&Z), expounded here and replied to here on WUWT. The other is by Hans Jelbring, discussed at Tallblokes Talkshop. As I understand their theories, they say that the combination of gravity plus an atmosphere without greenhouse gases (GHGs) is capable of doing what the greenhouse effect does—raise the earth at least 30°C above what we might call the “theoretical Stefan-Boltzmann (S-B) temperature.”
So what is the S-B temperature, theoretical or otherwise?
A curious fact is that almost everything around us is continually radiating energy in the infrared frequencies. You, me, the trees, the ocean, clouds, ice, all the common stuff gives off infrared radiation. That’s how night-vision goggles work, they let you see in the infrared. Here’s another oddity. Ice, despite being brilliant white because it reflects slmost all visible light, absorbs infrared very well (absorptivity > 0.90). It turns out that most things absorb (and thus emit) infrared quite well, including the ocean, and plants (see Note 3 below). Because of this, the planet is often treated as a “blackbody” for IR, a perfect absorber and a perfect emitter of infrared radiation. The error introduced in that way is small for first-cut calculations.
The Stefan-Boltzmann equation specifies how much radiation is emitted at a given temperature. It states that the radiation increases much faster than the temperature. It turns out that radiation is proportional to absolute temperature to the fourth power. The equation, for those math inclined, is
Radiation = Emissivity times SBconstant times Temperature^4
where the Stefan-Boltzmann constant is a tiny number, 0.0000000567 (5.67E-8). For a blackbody, emissivity = 1.
This “fourth-power” dependence means that if you double the absolute temperature (measured in kelvins), you get sixteen (2^4) times the radiation (measured in watts per square metre, “W/m2”). We can also look at it the other way, that temperature varies as the fourth root of radiation. That means if we double the radiation, the temperature only goes up by about 20% (2^0.25)
Let me call the “theoretical S-B temperature” the temperature that an evenly heated stationary blackbody planet in outer space would have for a given level of incoming radiation in W/m2. It is “theoretical”, because a real, revolving airless planet getting heated by a sun with the same average radiation will be cooler than that theoretical S-B temperature. We might imagine that there are thousands of mini-suns in a sphere around the planet, so the surface heating is perfectly even.
Figure 1. Planet lit by multiple suns. Image Source.
On average day and night over the planetary surface, the Earth receives about 240 W/m2 of energy from the sun. The theoretical S-B temperature for this amount of radiation (if it were evenly distributed) is about -18°C, well below freezing. But instead of being frozen, the planet is at about +14°C or so. That’s about thirty degrees above the theoretical S-B temperature. So why isn’t the planet a block of ice?
Let me take a short detour on the way to answering that question in order to introduce the concept of the “elevator speech” to those unfamiliar with the idea.
The “elevator speech” is simply a distillation of an idea down to its very basics. It is how I would explain my idea to you if I only had the length of an elevator ride to explain it. As such it has two extremely important functions:
1. It forces me to clarify my own ideas on whatever I’m discussing. I can’t get into handwaving and hyperbole, I can’t be unclear about what I’m claiming, if I only have a few sentences to work with.
2. It allows me to clearly communicate those ideas to others.
In recent discussions on the subject, I have been asking for that kind of “elevator speech” distillation of Jelbring’s or Nikolov’s ideas, so that a) I can see if whoever is explaining the theory really understands what they are saying and, if so, then b) so that I can gain an understanding of the ideas of Jelbring or Nikolov to see if I am missing something important.
Let me give you an example to show what I mean. Here’s an elevator speech about the greenhouse effect:
The poorly-named “greenhouse effect” works as follows:
• The surface of the earth emits energy in the form of thermal longwave radiation.
• Some of that energy is absorbed by greenhouse gases (GHGs) in the atmosphere.
• In turn, some of that absorbed energy is radiated by the atmosphere back to the surface.
• As a result of absorbing that energy from the atmosphere, the surface is warmer than it would be in the absence of the GHGs.
OK, that’s my elevator speech about why the Earth is not a block of ice. Note that it is not just saying what is happening. It is saying how it is happening as well.
I have asked, over and over, on various threads, for people who understand either the N&Z theory or the Jelbring theory, to give me the equivalent elevator speech regarding either or both of those theories. I have gotten nothing scientific so far. Oh, there’s the usual handwaving, vague claims of things like ‘the extra heat at the surface, is just borrowed by the work due to gravity, from the higher up regions of the atmosphere‘ with no mechanism for the “borrowing”, that kind of empty statement. But nothing with any meat, nothing with any substance, nothing with any explanatory value or scientific content.
So to begin with, let me renew my call for the elevator speech on either theory. Both of them make my head hurt, I can’t really follow their vague descriptions. So … is anyone who understands either theory willing to step forward and explain it in four or five sentences?
But that’s not really why I’m writing this. I’m writing this because of the claims of the promoters of the two theories. They say that somehow a combination of gravity and a transparent, GHG-free atmosphere can conspire to push the temperature of a planet well above the theoretical S-B temperature, to a condition similar to that of the Earth.
I hold that with a transparent GHG-free atmosphere, neither the hypothetical “N&Z effect” nor the “Jelbring effect” can possibly raise the planetary temperature above the theoretical S-B temperature. But I also make a much more general claim. I hold it can be proven that there is no possible mechanism involving gravity and the atmosphere that can raise the temperature of a planet with a transparent GHG-free atmosphere above the theoretical S-B temperature.
The proof is by contradiction. This is a proof where you assume that the theorem is right, and then show that if it is right it leads to an impossible situation, so it cannot possibly be right.
So let us assume that we have the airless perfectly evenly heated blackbody planet that I spoke of above, evenly surrounded by a sphere of mini-suns. The temperature of this theoretical planet is, of course, the theoretical S-B temperature.
Now suppose we add an atmosphere to the planet, a transparent GHG-free atmosphere. If the theories of N&K and Jelbring are correct, the temperature of the planet will rise.
But when the temperature of a perfect blackbody planet rises … the surface radiation of that planet must rise as well.
And because the atmosphere is transparent, this means that the planet is radiating to space more energy than it receives. This is an obvious violation of conservation of energy, so any theories proposing such a warming must be incorrect.
Q.E.D.
Now, I’m happy for folks to comment on this proof, or to give us their elevator speech about the Jelbring or the N&Z hypothesis. I’m not happy to be abused for my supposed stupidity, nor attacked for my views, nor pilloried for claimed errors of commission and omission. People are already way too passionate about this stuff. Roger Tattersall, the author of the blog “Tallbloke’s Talkshop”, has banned Joel Shore for saying that the N&Z hypothesis violates conservation of energy. Roger’s exact words to Joel were:
… you’re not posting here unless and until you apologise to Nikolov and Zeller for spreading misinformation about conservation of energy in their theory all over the blogosphere and failing to correct it.
Now, I have done the very same thing that Joel did. I’ve said around the web that the N&Z theory violates conservation of energy. So I went to the Talkshop and asked, even implored, Roger not to do such a foolish and anti-scientific thing as banning someone for their scientific views. Since I hold the same views and I committed the same thought-crimes, it was more than theoretical to me. Roger has remained obdurate, however, so I am no longer able to post there in good conscience. Roger Tallbloke has been a gentleman throughout, as is his style, and I hated to leave. But I did what Joel did, I too said N&Z violated conservation of energy, so in solidarity and fairness I’m not posting at the Talkshop anymore.
And more to the point, even if I hadn’t done what Joel did, my practice is to never post at or even visit sites like RealClimate, Tamino’s, and now Tallbloke’s Talkshop, places that ban and censor scientific views. I don’t want to be responsible for their page views counter to go up by even one. Banning and censorship are anathema to me, and I protest them in the only way I can. I leave them behind to discuss their ideas in their now cleansed, peaceful, sanitized, and intellectually sterile echo chamber, free from those pesky contrary views … and I invite others to vote with their feet as well.
But I digress, my point is that passions are running high on this topic, so let’s see if we can keep the discussion at least relatively chill …
TO CONCLUDE: I’m interested in people who can either show that my proof is wrong, or who will give us your elevator speech about the science underlying either N&K or Jelbring’s theory. No new theories need apply, we have enough for this post. And no long complicated explanations, please. I have boiled the greenhouse effect down to four sentences. See if you can match that regarding the N&K or the Jelbring effect.
w.
NOTE 1: Here’s the thing about a planet with a transparent atmosphere. There is only one object that can radiate to space, the surface. As a result, it is constrained to emit the exact amount of radiation it absorbs. So there are no gravity/atmospheric phenomena that can change that. It cannot emit more or less than what it absorbs while staying at the same temperature, conservation of energy ensures that. This means that while the temperature can be lower than the theoretical S-B temperature, as is the case with the moon, it cannot be more than the theoretical S-B temperature. To do that it would have to radiate more than it is receiving, and that breaks the conservation of energy.
Once you have GHGs in the atmosphere, of course, some of the surface radiation can get absorbed in the atmosphere. In that case, the surface radiation is no longer constrained, and the surface is free to take up a higher temperature while the system as a whole emits the same amount of radiation to space that it absorbs.
NOTE 2: An atmosphere, even a GHG-free atmosphere, can reduce the cooling due to uneven insolation. The hottest possible average temperature for a given average level of radiation (W/m2) occurs when the heating is uniform in both time and space. If the total surface radiation remains the same (as it must with a transparent atmosphere), any variations in temperature from that uniform state will lower the average temperature. Variations include day/night temperature differences, and equator/polar differences. Since any atmosphere can reduce the size of e.g. day/night temperature swings, even a transparent GHG-free atmosphere will reduce the amount of cooling caused by the temperature swings. See here for further discussion.
But what such an atmosphere cannot do is raise the temperature beyond the theoretical maximum average temperature for that given level of incoming radiation. That’s against the law … of conservation of energy.
NOTE 3: My bible for many things climatish, including the emissivity (which is equal to the absorptivity) of common substances, is Geiger’s The Climate Near The Ground, first published sometime around the fifties when people still measured things instead of modeling them. He gives the following figures for IR emissivity at 9 to 12 microns:
Water, 0.96 Fresh snow, 0.99 Dry sand, 0.95 Wet sand, 0.96 Forest, deciduous, 0.95 Forest, conifer, 0.97 Leaves Corn, Beans, 0.94
and so on down to things like:
Mouse fur, 0.94 Glass, 0.94
You can see why the error from considering the earth as a blackbody in the IR is quite small.
I must admit, though, that I do greatly enjoy the idea of some boffin at midnight in his laboratory measuring the emissivity of common substances when he hears the snap of the mousetrap he set earlier, and he thinks, hmmm …
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steveta_uk says:
January 15, 2012 at 4:04 pm
“And a final note to those who believe all matter must radiate until it reaches absolute zero. . Considier a single N2 molecule out in space. Is it radiating?”
In cold space, it will radiate until it reaches its ground state, which could take infinite time to reach. A macroscopic quantity of matter collectively in its ground state is, by definition, at absolute zero.
“For that matter, does it have a temperature?”
No. Temperature is a macroscopic measure whose definition breaks down at that level.
“The only thing averaging the energy from the sun, does is tell you how much something with 4 times the surface area can radiate.”
And btw, the planet with million sun which provide 240 Watts per square meter, would be radiating
a million times more energy than earth.
“Both make the erroneous assumption that somehow the adiabatic lapse rate determines a temperature. It does not.”
It does. Temperature meaning air temperature. Air temperature is always discussed as earth temperature. So corrected, adiabatic lapse rate determines air temperature.
The only with saying that is it’s too darn obvious.
Thought experiment:
Remove all oceans from earth.
Perhaps a less obvious thing other than the absence of water,
is you create a world with high plateau [the land masses]. Most the planet if removed
the ocean would have 3 km deeper atmosphere.
At the bottom of these once exist ocean floors, the air temperature would higher- due to the
adiabatic lapse rate.
To summarise the story so far:
1) Willis accepts that his non GHG atmosphere will produce a dry adiabatic lapse rate with the warmest temperatures at the surface.
2) The warmth at the surface is NOT due to gravitational compression but gravity is responsible for placing the maximum density of non GHG molecules at trhe base of the atmospheric column.
3) That maximimum density causes the greatest number of molecular collisions to occur just above the surface.
4) Such collisions transfer energy by conduction and not radiation. Their effect is to convert incoming solar shortwave radiative energy into kinetic energy and to retain it longer until it can be released upward as outgoing longwave IR.
5) It is that delay that increases the surface temperature.
6) That delay is caused by gravity concentrating the maximum density of atmospheric molecules at the surface and the greater the density, the longer the delay and the higher the equilibrium temperature must become.
c0h0nes says:
January 15, 2012 at 4:33 pm
According to the description in the head post, it is an evenly heated planet, no polar or equatorial insolation … READ THE HEAD POST BEFORE COMMENTING!!!
Thanks, sorry for shouting but not reading the head post is simply not acceptable.
w.
Surfer Dave says:
January 15, 2012 at 4:51 pm
“Over an infinite period of time the planet would not the core of the planet reach the temperature of your array of suns?”
Since the equations of thermal equilibrium are the same as for the gravitational potential, I would guess that the temperature profile would settle out such that it decreased proportional to radius squared.
Since Tallbloke first published the “Unified Theory of Climate” by N & Z, and reminded everyone about Hans Jellbring’s hypothesis, I have watched the melting of the inimitable Willis Eschenbach’s mind in fascination. I feel I must attempt to put out the fire in his head before it consumes him completely. I have enjoyed most of his earlier perspicacious writings and do not want to lose him.
I believe Willis’ approach to this theory is revealing: (a) it makes his head hurt; (b) he wants someone else to explain where his thinking is wrong.
Well, I would hate to see him self-destruct due “excess heat” build-up in his head so I offer the following (including my “elevator speech”) as an antidote to his dilemma. Be honest with yourself, Willis. The fact this alternative theory makes your head hurt is a sign of “impending change”; your paradigm is being altered and that is making you uncomfortable.
The biggest trouble with thought experiments, Willis, is that if you are not extremely careful, you can end up believing that things like M C Escher’s impossible “ascending-descending” stairway is physically possible. The main problem is that there is no “reality check” built into a thought experiment. That is why Einstein’s relativity theory led to the TWIN PARADOX.
You should be able to agree that paradoxes do not exist in REALITY, but only in the mind, generally as a result of false premises in the logical process which generates them as a part of their “logical conclusion”.
For me, the Greenhouse Gas Theory is in the same class as the Escher stairway (or the Twin Paradox of Relativity, or the Wave-Particle Duality of Planck and others). If you believe any one of these things is possible, and are prepared to defend it as “a reality”, you have already “lost the plot”. You have effectively surrendered your intellect to a smooth-talking con-man.
The false premise in the ‘GG theory’ is the postulated existence of the effect of ‘back radiation’ from a cold atmospheric trace gas, namely, that such a ‘cool’ gas can cause a ‘warmer’ surface to be raised to a higher temperature than it would otherwise be, without the presence of the ‘cool’ gas. If this does not seem to you to be the quintessential recipe for a perpetual motion device, then you have lost the essential critical faculty which defines a scientific mind.
As for the Atmospheric Temperature Enhancement (ATE; NTE) postulated by N & Z, here is my “elevator speech”:
·1. The existence of a dimensionless Thermal Expansion Coefficient of steel does not imply that “gravity cause steel to expand”.
·2. Likewise, the existence of a dimensionless ATE ‘factor’ does not imply that “gravity causes heating of the lower atmosphere”, in defiance of the 2nd Law of Thermodynamics.
·3. In both cases, the dimensionless ratio in question enables us to calculate easily what the effect of “heat input” will be on, in the first case, a bar of steel and, in the second case, a planetary atmosphere subjected to gravitational compression.
I hope that did not strain your attention span, Willis. From that point on, you should be able follow the logic. I’ll leave the pleasure of that process of discovery for you to enjoy at your own pace.
Reed Coray says:
January 15, 2012 at 4:42 pm
Thanks, Reed, good question. You are right not to let your mistakes stop you, and you have done the right thing in the right order:
a) admit the mistake, and
b) move on to the next interesting scientific question.
The answer is, the physics of the situation stops it. See my posts “The Steel Greenhouse” and ” People Living In Glass Planets” for how that works, with the details of the accounting.
Regards,
w.
If the blackbody object had an atmosphere of the non-GHG hydrogen 695,000 kms thick, the blackbody object would heat up to about 10 million Kelvin, then hydrogen fusion would start and the blackbody object would then heat up to about 15 million Kelvin.
Bart says:
January 15, 2012 at 5:02 pm
Thanks, Bart. True, but how is that relevant? I said because the planet is at thermodynamic equilibrium there is no exchange of heat across the interface, not the other way around as you have it.
You can only “assure me” if you can explain how that might work to me. I fear your unaccompanied assurance is greatly inadequate. On the planet I described, once it is warmed up to its equilibrium state, the temperature equilibrium of the surface will be totally unchanged.
You seem to have forgotten, the temperature of the planet in the head post is fixed by the amount of incoming radiation it is absorbing. It has to radiate what it absorbs. As a result, the temperature is neither set nor affected by the transparent GHG-free atmosphere. It makes absolutely no difference. Here’s how I explained it in the head post:
You go on to say:
My dear friend, that is exactly why we do thought experiments, to simplify a complex situation. In this case the thought experiment lets us know the magnitude of the difference with and without a transparent GHG-free atmosphere is zero.
Einstein used gedanken experiments to understand relativity, so your objection that ‘it’s too complex’ doesn’t hold water. It’s not as complex as relativity.
Absent that, we have thought experiments such as mine above. I endeavor to make the most of what we have.
Regards,
w.
Willis,
I’m a tad timorous to ask, but:
1) Didn’t you agree elsewhere that the moon does not exhibit the expected S-B behavior based on the so-called average or effective radiative temperature, spread over 4Pi*r^2? One reason for this is that there is an extreme hotspot directly under the sun which loses heat proportionally to the fourth power of T. (= very much more than elsewhere). In an Earth with transparent atmosphere the insolation in the solar hotspot would be practically identical, although some of the resultant heat would be conducted/convected/advected away. (BTW, even at hurricane wind-speeds, this would be a relatively slow process). Paraphrasing, I think you have claimed that it is impossible for the surface of a planet to radiate more than that of the theoretical value of the black body equivalent of the insolation.
Where that simplistic statement fails is that temporally and spatially, there is no sensible temperature on which to base your assertion, because of that naughty T^4. (and some other things)
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Willis, if you are kind and sympathetic towards me on point 1), I may contemplate submitting point 2) and beyond, that you seem to have overlooked.
Whoops,
Further my post just above, where I wrote:
Paraphrasing, I think you have claimed that it is impossible for the surface of a planet to radiate more than that of the theoretical value of the black body equivalent of the insolation.
I should have added, according to standard climate science: unless there are GHG’s present
Willis wrote;
“Let me give you an example to show what I mean. Here’s an elevator speech about the greenhouse effect:
The poorly-named “greenhouse effect” works as follows:
• The surface of the earth emits energy in the form of thermal longwave radiation.
• Some of that energy is absorbed by greenhouse gases (GHGs) in the atmosphere.
• In turn, some of that absorbed energy is radiated by the atmosphere back to the surface.
• As a result of absorbing that energy from the atmosphere, the surface is warmer than it would be in the absence of the GHGs.
OK, that’s my elevator speech about why the Earth is not a block of ice. Note that it is not just saying what is happening. It is saying how it is happening as well.”
Ok, here is your elevator speech with appropriate corrections;
Let me give you an example to show what I mean. Here’s an elevator speech about the greenhouse effect:
The poorly-named “greenhouse effect” works as follows:
• The surface of the earth emits energy in the form of thermal longwave radiation. AND THEN IT COOLS BY AN AMOUNT THAT CORRESPONDS TO THE ENERGY RADIATED (REFERENCE: FIRST LAW)
• Some of that energy is absorbed by greenhouse gases (GHGs) in the atmosphere. YES INDEED IT IS.
• In turn, some of that absorbed energy is radiated by the atmosphere back to the surface. AND THEN THE ATMOSPHERE COOLS BY AN AMOUNT THAT CORRESPONDS TO THE ENERGY RADIATED (REFERENCE: FIRST LAW)
• As a result of absorbing that energy from the atmosphere, the surface is warmer than it would be in the absence of the GHGs. NO NO NO NO…… the surface is simply warmed (and then cools) a second, third, fourth, etc. time as the energy makes a few small (and very speedy, i.e. at the speed of light) side trips through the system.
I’m sorry good sir, but your elevator ran off the tracks at your step #1.
The “GHE” only delays the flow of energy through the Sun/Earth/Atmospheres/Universe system by at most 10 to 100 milliseconds. Since this is far less than the period of One day (~86 million milliseconds) no “Extra Energy” is left over at the end of each day to cause a “Higher Equilibrium” to exist. OK, that’s my elevator speech.
Just a couple of other observations;
The S-B law (and it closely related relatives) are reasonably good at predicting the amplitude and/or spectral content of the radiation from a surface, but it is THEORETICAL, no real object yet observed agrees completely with the theory.
HOWEVER, and this is a REALLY BIG HOWEVER, it (the S-B law) says NOTHING about the temperature that a volume will reach when it absorbs radiation that happens to closely follow the S-B law. There are far more factors involved, like the thermal capacity and thermal diffusivity of the absorbing materials. And of course the volume of the respective materials MUST be considered. The hypothesis that the miniscule thermal capacities of the alleged GHGs are in fact “forcing” the MASSIVE thermal capacities of the Oceans present on the Earth into thermal equilibrium with said gases will be seen as LAUGHABLE in a few more years’ time.
Other than that, your post is quite interesting.
Cheers, Kevin.
jjthom says:
January 15, 2012 at 4:59 pm
Many thanks, jthom. An excellent and clear explanation of why some gases absorb/emit in the IR frequencies and some are transparent to IR.
w
Willis is correct for the hypothetical situation he describes. An IR transparent atmosphere cannot influence the surface temperature. However I feel this is misleading. In the real world, only 30% (on average) of the Earth’s surface is open to the sky. 70% is cloud cover. In this situation, the temperature of the radiating surfaces of clouds becomes important and this is influenced by the lapse rate of an IR transparent atmosphere. Cloud cover also reduces the effect of GHGs.
I’d also like to contratulate Willis for the great effort he has put into responses.
The issue lies with the exact definition of GHG and consequently the definition of what a non-GHG atmosphere would be like. You seem to be asserting that a non-GHG atmosphere cannot participate in any radiative processes – that the gases must be totally transparent to all frequencies. Under that definition your argument is sound. The energy budget of the entire planet must balance and with those restrictions the only way energy can enter/leave THE PLANET (many people are missing that unsubtle point) is by radiation at the surface which determines the temperature there. QED.
However where I must take issue with you is that I believe your definition of GHG to be too restrictive, non-standard and in fact incorrect. To you a GHG is simply any gas which is not completely transparent. So all gases are GHGs to some extent under your definition. I’d say that GHGs are gases which are transparent at the frequencies emitted by the sun but absorb the frequencies emitted by the planet. So energy has an easier time getting in than out. This aspect of the greenhouse effect was completely missing from your elevator description. If I were riding in that elevator with you I’d say “but surely the GHGs also absorb the sun’s energy coming in, cooling the planet”, and I’d claim to have a back of the envelope calculation showing that if all frequencies are absorbed equivalently, the two effects would balance. And I think you’d respond to that comment by modifying your description along the lines indicated above – that the frequencies emitted by the planet are absorbed more strongly than those emitted by the sun. However as a consequence you would no longer be able to assert that non-GHGs must be perfectly transparent.
To me a GHG is a gas which absorbs longwave radiation more strongly than shortwave radiation. A planet with a non-GHG atmosphere is therefore not one with a completely transparent atmosphere, but rather one where the atmosphere is equally transparent at all frequencies. So the atmosphere can indeed absorb and radiate, but must do so at all frequencies equally.
Under my definition even a perfectly opaque gas would be a non-GHG since it treats all frequencies equally (it absorbs them all). Let’s consider that extreme example for a minute because it is instructive. Under the conditions of a perfectly opaque atmosphere, the radiative balance occurs at the top of the atmosphere, not the bottom. So that is where the Boltzman radiative equilibrium temperature is located. The temperature at the surface is then determined from the temperature at the top of the atmosphere by the lapse rate which arises from purely convective processes and has nothing to do with radiative properties at all. As gases fall in the atmosphere compression heats them. As they rise they cool. So vertical mixing establishes a vertical temperature gradient and temperature at the surface is therefore hotter than the temperature at the top of the atmosphere. A thicker atmosphere in this model would make for a hotter surface. QED
Now imagine the atmosphere of such a world gradually becoming less opaque until it became totally transparent. At the end of that process we’d be back at your model with the Boltzmann temperature at the surface. But in between we’d be in a much more realistic complicated state with the Boltzmann temperature at an intermediate depth in the atmosphere and the surface somewhat hotter. How much hotter depends on many things – on the lapse rate (which depends on the amount of vertical mixing)- on the opacity – on the depth of the atmosphere. And this happens with at no stage any of the gases being “greenhouse” in the classical sense since we maintain the requirement that they absorb an equal fraction of the radiation at all frequencies throughout.
Stephen Wilde says:
January 15, 2012 at 5:44 pm
No, I don’t “accept” that. I knew that when I wrote the post. It is correct, however, so OK
OK
OK
No. At equilibrium, the atmosphere is quiet, with no energy going into or out of it. Collisions are exchanging energy, not transferring energy. It’s not going anywhere.
No GHGs, so no radiation from the atmosphere. In other words, no GHGs, no radiation. That is to say, here can’t be radiation because there are no GHGs. Or we could put it as the lack of GHGs prevents the atmosphere from radiating.
Since your explanation has gone off the rails, I’ll stop there. However, I encourage you to continue the thought process leaving out the radiation to see where that leads.
w.
I can improve on my previous summary thus:
1) Willis accepts that his non GHG atmosphere will produce a dry adiabatic lapse rate with the warmest temperature at the surface.
2) The warmth at the surface is NOT due to gravitational compression ( although a tiny fraction of it would be) but gravity IS responsible for placing the maximum density of non GHG molecules at the base of the atmospheric column.
3) That maximimum density causes the greatest number of molecular collisions to occur just above, or in contact with, the surface.
4) Such collisions transfer energy by conduction and not radiation. The surface converts incoming solar shortwave radiative energy into kinetic energy and the non GHG gases in contact with or in close proximity to the surface retain that kinetic energy by exchanging the energy via conduction between molecules of non GHGs until it can be released upward as outgoing longwave IR.
5) It is that delay that allows the surface temperature to rise as energy accumulates within the system and most particularly at or just above the surface.
6) The greater the density of the non GHG atmosphere, the more molecular collisions occur and the longer the delay the higher the equilibrium temperature must become. The increased density does NOT slow down the rate of conduction. Instead it increases the proportion of fast moving radiation that is retained for longer as slower moving conduction for an average net reduction in energy flow through the system.
[COMMENT: We cross-posted, Stephen, see my post above. Thanks, -w.]
OzWizard says:
January 15, 2012 at 5:54 pm
Gosh, Ozwizard, you sure know how to make an entrance. Start by abusing and patronizing the guy who wrote the post. Claim omniscience about what is going on. Insult me in a variety of manners. Does your momma know you enter a group like that?
So, more patronizing, more self-aggrandizement, more insults. Nothing scientific yet.
Honestly? What makes my head hurt are random internet “experts” like yourself who spend the first half of your very first post in this thread insulting me.
As a result, OzWizard, no, I’m not going to discuss your genius thoughts. I’m not going to engage with your massive intellect. I’m going to go no further.
If you would like to get some traction, Wiz, first, start over. Second, lose the farkin’ attitude, you are a random anonymous internet poster just entering the thread who has done nothing to earn it. Third, boil your elevator speech down to about half whatever you think you can do. Then start over and shoot to explain it in half the sentences.
Come back with that and we’ll talk. Or not. Up to you.
w.
Bob Fernley-Jones says:
January 15, 2012 at 6:28 pm
Bob, if I understand you, Dennis Wingo talked about this upthread, you might have missed it. I said:
So I am in mystery as to what a hotspot on earth has to do with this discussion. We’re discussing an evenly heated planet, specifically to avoid all those ugly T^4 complications.
w.
Willis, just seen your comments which suggest more clarity needed on my part so here goes again:
1) Willis knows that his non GHG atmosphere will produce a dry adiabatic lapse rate with the warmest temperature at the surface.I am assuming some movement via convection to achieve it.
2) The warmth at the surface is NOT due to gravitational compression ( although a tiny fraction of it would be) but gravity IS responsible for placing the maximum density of non GHG molecules at the base of the atmospheric column.
3) That maximimum density causes the greatest number of molecular collisions to occur just above, or in contact with, the surface.
4) Such collisions transfer energy between themselves by conduction and not radiation. The surface converts incoming solar shortwave radiative energy into kinetic energy and the non GHG gases in contact with or in close proximity to the surface retain that kinetic energy by exchanging the energy via conduction between themselves and between themselves and the surface until it can be released upward by the surface as outgoing longwave IR.
5) It is that delay that allows the surface temperature to rise as energy accumulates within the system and most particularly at or just above the surface.
6) The greater the density of the non GHG atmosphere, the more molecular collisions occur, the longer the delay and the higher the equilibrium temperature must become. The increased density does NOT slow down the rate of conduction. Instead it increases the proportion of fast moving radiation that is retained for longer as slower moving conduction for an average net reduction in energy flow through the system.
Any further comments ?
“I’d say that GHGs are gases which are transparent at the frequencies emitted by the sun but absorb the frequencies emitted by the planet. ”
CO2, H20, O2, and O3 are not greenhouse gases acorrding to your definition:
http://en.wikipedia.org/wiki/File:Solar_Spectrum.png
From:
http://en.wikipedia.org/wiki/Sunlight
Dr Burns says:
January 15, 2012 at 6:58 pm
Thanks, Dr. B. But misleading? I have shown that there is no way for an IR transparent atmosphere to affect the surface temperature. What is misleading about that?
The way it is relevant to the real world is that in the real world people are being misled by the hypotheses of Jelbring and N&Z. They theorize that some kind of atmospheric/gravity interaction is what is warming the earth to about 30°C above the theoretical S-B temperature. They claim it doesn’t require GHGs. My proof shows that they are incorrect, that their claims violate the conservation of energy.
Thank you sir.
w.
4) Such collisions transfer energy by conduction and not radiation.
“No. At equilibrium, the atmosphere is quiet, with no energy going into or out of it. Collisions are exchanging energy, not transferring energy. It’s not going anywhere.”
Do you accept if it’s windy, one has transfer by conduction?
I disagree with4] since I would say it’s convection rather than conduction- with air, conduction is normally slow.
Fiberglass insulation indicates this. The fiberglass in term of volume is mostly air, the fiberglass inhibits the the air from convecting heat.
I should add this:
7) At equilibrium we now have solar shortwave hitting the surface at 240W/m2 and IR longwave leaving the surface at 240W/m2 but additionally we now have a backed up pool of kinetic energy bouncing between air molecules at the surface and between those molercules and the surface giving the necessary temperature boost at the surface.