Heh. In response to a ridiculous claim making the rounds (I get comment bombed at WUWT daily with that nonsense) which I debunked here: A misinterpreted claim about a NASA press release, CO2, solar flares, and the thermosphere is making the rounds
Dr. Roy Spencer employs some power visual satire, that has truth in it. He writes:
How Can Home Insulation Keep Your House Warmer, When It Cools Your House?!
<sarc> There is an obvious conspiracy from the HVAC and home repair industry, who for years have been telling us to add more insulation to our homes to keep them warmer in winter.
But we all know, from basic thermodynamics, that since insulation conducts heat from the warm interior to the cold outside, it actually COOLS the house.
Go read his entire essay here. <Sarc> on, Roy!
UPDATE: Even Monckton thinks these ideas promoted by slayers/principia/O’Sullivan are ridiculous:
Reply to John O’Sullivan:
One John O’Sullivan has written me a confused and scientifically illiterate “open letter” in which he describes me as a “greenhouse gas promoter”. I do not promote greenhouse gases.
He says I have “carefully styled [my]self ‘science adviser’ to Margaret Thatcher. Others, not I, have used that term. For four years I advised the Prime Minister on various policy matters, including science.
He says I was wrong to say in 1986 that added CO2 in the air would cause some warming. Since 1986 there has been some warming. Some of it may have been caused by CO2.
He says a paper by me admits the “tell-tale greenhouse-effect ‘hot spot’ in the atmosphere isn’t there”. The “hot spot”, which I named, ought to be there whatever the cause of the warming. The IPCC was wrong to assert that it would only arise from greenhouse warming. Its absence indicates either that there has been no warming (confirming the past two decades’ temperature records) or that tropical surface temperatures are inadequately measured.
He misrepresents Professor Richard Lindzen and Dr. Roy Spencer by a series of crude over-simplifications. If he has concerns about their results, he should address his concerns to them, not to me.
He invites me to “throw out” my “shredded blanket effect” of greenhouse gases that “traps” heat. It is Al Gore, not I, who talks of a “blanket” that “traps” heat. Interaction of greenhouse gases with photons at certain absorption wavelengths induces a quantum resonance in the gas molecules, emitting heat directly. It is more like turning on a tiny radiator than trapping heat with a blanket. Therefore, he is wrong to describe CO2 as a “coolant” with respect to global temperature.
He invites me to explain why Al Gore faked a televised experiment. That is a question for Mr. Gore.
He says I am wrong to assert that blackbodies have albedo. Here, he confuses two distinct methods of radiative transfer at a surface: absorption/emission (in which the Earth is a near-blackbody, displacing incoming radiance to the near-infrared in accordance with Wien’s law), and reflection (by which clouds and ice reflect the Sun’s radiance without displacing its incoming wavelengths).
He implicitly attributes Margaret Thatcher’s 1988 speech to the Royal Society about global warming to me. I had ceased to work with her in 1986.
He says that if I checked my history I should discover that it was not until 1981 that scientists were seriously considering CO2’s impact on climate. However, Joseph Fourier had posited the greenhouse effect some 200 years previously; Tyndale had measured the greenhouse effect of various gases at the Royal Institution in London in 1859; Arrhenius had predicted in 1896 that a doubling of CO2 concentration would cause 4-8 K warming, and had revised this estimate to 1.6 K in 1906; Callender had sounded a strong note of alarm in 1938; and numerous scientists, including Manabe&Wetherald (1976) had attempted to determine climate sensitivity before Hansen’s 1981 paper.
He says, with characteristic snide offensiveness, that I “crassly” attribute the “heat-trapping properties of latent heat to a trace gas that is a perfect energy emitter”. On the contrary: in its absorption bands, CO2 absorbs the energy of a photon and emits heat by quantum resonance.
He says the American Meteorological Society found in 1951 that all the long-wave radiation that might otherwise have been absorbed by CO2 was “already absorbed by water vapor”. It is now known that, though that is largely true for the lower troposphere, it is often false for the upper.
The series of elementary errors he here perpetrates, delivered with an unbecoming, cranky arrogance, indicates the need for considerable elementary education on his part. I refer him to Dr. Spencer’s excellent plain-English account of how we know there is a greenhouse effect.
The Viscount Monckton of Brenchley (April 18, 2013)
joeldshore its pretty obvious that you have reading difficulties and further cannot separate real issues from trivia.
I said
“I gave the textbook and page number and since the book is linked online we can let readers decide what part radiation plays in glasshouses or atmospheric greenhouse analogs”
You said
“No…You gave us the name of the book and the year.”
I said above on May 3, 2013 at 8:50 am
“Can you read?
Look at Nelkon & Parker page 360”
Since there is an online link readers can check for themselves how much part trapped radiation plays in the heating of a greenhouse.
Answer is nothing or negligible according to Nelkon and Parker in line with the experimental results of R W Wood whose views were accepted by all physicists at the time as far as I know.
All subsequent reliable tests confirm Woods findings which must be a bummer for alarmists but you cannot argue with experimental results.
I’m off now for a sailing trip for the next 3 days so my educational efforts here will have to be suspended.
Bryan: Everyone can plainly see the sort of deception and sophistry that characterizes your posts here. You badly misrepresented what a textbook said and now you make statements that continue to badly misrepresent the arguments of those who understand the greenhouse effect. You don’t educate; you simply confuse.
Kristian says:
Kristian: If you really think about this statement, maybe we can take you from your view of physics as some sort of arbitrary and capricious magic to the true beauty of physics. What exactly is it that prevents the energy going the other way from having any effect? Energy is energy and if there is a flow of energy that energy is going to have an effect on the temperature, which is a measure of the internal (or “thermal”) energy of an object. So, is there a little sign on the warm object that says: “No energy flows from colder objects allows?” Do the photons get turned back at the boundary or does there energy they have magically disappear?
The whole beauty and mystery of the 2nd Law of Thermodynamics is exactly the opposite: It is the story about how laws like the fact that heat flows only from warmer to colder objects, facts that give a direction to the arrow of time, arise at the macroscopic scale from completely reversible behaviors on the microscopic scale. The whole idea is that at the level of individual photons, there are no arbitrary and capricious laws. Photons go where they want; deposit their energy when they interact with matter, irregardless of the temperature (since in fact, there isn’t really such a thing as “temperature” at the level of individual atoms or molecules they interact with).
From a real physics point-of-view, the fact that heat flows from hot to cold doesn’t arise from arbitrary and capricious laws about how energy behaves differently in different situations. It arises from the fact that because the rate at which objects emit radiation increases with their temperature, the energy flow from the hot object to the cold object is always greater than the energy flow from the cold object to the cold object and hence, in an interaction involving these two objects only, the hot object will get colder and the colder one hotter until they come to equilibrium.
Now, let’s imagine there are 3 “objects”: The sun, the Earth, and space. The sun is at its temperature T_S, space is at absolute zero (well, really about 3K, but let’s not quibble) and the Earth’s temperature is determined by the need to balance the energy it receives from the sun and the energy it emits back out into space. Note that the heat, or net energy flow, is from sun to Earth to space.
Now, add a 4th object: an IR-absorbing atmosphere. Now, the temperature of the Earth (and the temperature of the atmosphere) will be determined by the more complicated energy balance involving all 4 objects. The claim that the temperature of the Earth in this case can’t be higher than in the case of 3 objects above has absolutely no foundation in the 2nd Law of Thermodynamics (or any other law of physics). It is simply made-up nonsense that relies on some sort of capricious view of the laws of physics that is much less beautiful and imaginative than the real laws of physics.
@joel Shore
You have been very reluctant to discuss the role of radiative gases in tropospheric convective circulation. Radiative gases are of course critical for continued convective circulation and atmospheric cooling in the troposphere. This has been established science for some time. A simple explanation of the role of radiative gases in convective circulation can be found here –
http://www.st-andrews.ac.uk/~dib2/climate/tropics.html
Without radiative cooling at altitude and convective circulation below the tropopause, our atmosphere would heat dramatically.
However at AGW supporter site Scienceofdoom we find this attempt to write the role of radiative gases in convective circulation out of atmospheric science –
http://scienceofdoom.com/2012/12/23/clouds-water-vapor-part-five-back-of-the-envelope-calcs-from-pierrehumbert/
– which includes the following summary of Pierrehumberts wholly un-empirical 1995 claims –
“So increasing the emissivity from zero (increasing “greenhouse” gases) cools the climate to begin with. Then as the emissivity increases past a certain point the warm pool surface temperatures start to increase again.”
You have often offered up Pierrehumberts work as justification for the AGW hypothesis, yet every time I have raised the issue of the role of radiative gases in cooling a moving atmosphere you have run back to static atmosphere two shell models. Do you support Pierrehumberts 1995 claims? Is there any other scientist you are aware of making such claims before 1990?
Konrad,
Before we think about moving on to a very different topic, do you now agree that your interpretation of energy flows and temperatures for the shells we have been discussing was completely wrong? Do you agree with Joel and Gary and me that a “bare” blackbody planet with heaters set to 400 W/m^2 will be 288 K, while the same planet with the same 400 W/m^2 heaters but now surrounded by a blackbody shell will be radiating 800 W/m^2 of thermal IR radiating @ur momisugly T=345 K (and receiving 400 W/m^2 of “back-radiation”) at the planet’s surface? (Or conversely, that we could lower the heaters to 200 W/m^2 and still keep the planet’s surface @ur momisugly 288 K when the shell is in place?)
Tim,
As I have argued at all times, the two shell radiative model is irrelevant to an atmosphere in which the gases are free to move. Again lets review the “do nots” of atmospheric modelling –
1. Do not model the “earth” as a combined land/ocean/gas “thingy”
2. Do not model the atmosphere as a single body or layer
3. Do not model the sun as a ¼ power constant source without diurnal cycle
4. Do not model conductive flux to and from the surface and atmosphere based on surface Tav
5. Do not model a static atmosphere without moving gases
6. Do not model a moving atmosphere without Gravity
7. Do not model the surface as a combined land/ocean “thingy”*
If you do not understand why these rules are important, then you do not understand the basic physics of convection and gas conduction. It appears that Pierrehumbert did realise radiative cooling at altitude is critical to tropospheric convective circulation. It appears that Pierrehumbert did realise that radiative gases cool our atmosphere at all concentrations above 0.0ppm. That is why he tried to get away with this –
“So increasing the emissivity from zero (increasing “greenhouse” gases) cools the climate to begin with. Then as the emissivity increases past a certain point the warm pool surface temperatures start to increase again.”
A “certain point” was it? How many ppm is that? Empirical evidence? Not likely. This attempt to write the role of radiative gases in convective circulation out of atmospheric science will not stand up to scrutiny. It is very clear why you and Joel hate discussing the role of radiative gases in convective circulation. You and Joel can try running back to your two shell models but it will not work. In a moving atmosphere, radiative gases act to cool the atmosphere at all concentrations above 0.0ppm. AGW is a physical impossibility for a moving atmosphere.
You know Pierrehumberts “it cools and then it warms” thing is tripe. I have given you plenty of opportunities to offer it up in response to questions of the role of radiative gases in a moving atmosphere. It seems even AGW believers are too embarrassed to repeat it.
Konrad: I am happy to discuss radiative gases in convective circulation and have explained it several times before – When you add more radiative gases under the current conditions, the condition on convection is determined by the fact that the lapse rate stays very close to the appropriate adiabatic lapse rate. For places where that is the dry adiabatic lapse rate, that means the lapse rate doesn’t change. For places where that is the saturated adiabatic lapse rate, that means the lapse rate decreases slightly. This is a negative feedback in all of the climate models that has the effect of taking back some of the amplification caused by the water vapor feedback.
But, the net effect of adding greenhouse gases is a warming of the troposphere.
Konrad, I owe you an apology.
The discussion was about shells and heat transfer, and I was focused on that discussion and mistook one “K” for another (Konrad for Kristian). Kristian was the one so adamantly (and incorrectly) proclaiming that the shell would not matter. Kristian is the one who hopefully has realized his mistakes.
Now on to a few other points:
1) This is a quote I like from George Box: “all models are wrong, but some are useful” The simplified models (like uniform heating and blackbody shells) are USEFUL for gaining understanding of various concepts.
2) Even when gases are free to move, the radiative shell models are not irrelevant. Convection certainly makes major modifications to the results of a simple shell model, but energy flow is ALWAYS relevant to temperature.
3) The Science of Doom article looks interesting — thanks for pointing it out. I haven’t had time to do more than skim through it. It DOES say that is is a simple model — that ignores several of your points about what a model MUST have, so it is certainly too simple for precise modeling of temperatures. I hope to have a chance to look further at it sometime soon.
It is simply stunning to see you people still so fundamentally confused and at the same time so self-assuredly certain about the shell having to make the sphere warmer than what its constant internal input can manage.
And this after you have failed to come up with even a single physics or engineering textbook example anywhere that describes this (one would think) important phenomenon or even mentions it as an eventuality or interesting corollary. Without having even one single controlled real-world vacuum chamber experiment to show for who proves this effect to be a real one as per your theory.
Without caring to answer me when I ask you why the alleged necessary heating of the sphere and the apparently well-established mechanism behind is never discussed anywhere in physics. Why it is always only how much cooler than the sphere the shell will end up being, and hence accordingly how much the flux to space will be reduced, that seems to be the subjects of interest and relevance. Why is it stated over and over again that the temperature of the sphere will remain constant, and yet never is it explained why and how, even with a word, that this constant temperature can only be sustained by a reduction in its internal power input to exactly match the ‘back radiation’ from the sphere? How the surface temperature of the sphere (like a star) is maintained constant by an equally constant internal input flux of, by necessity, a set magnitude, as long as it’s alone in space, but how this abruptly changes when the shell is put in place around it, by a sudden and perfectly balanced reduction in the internal input power. Wouldn’t it be prudent to tell easily bewildered young student minds that their possibly natural intuitive first assumption (by Occam’s razor) that a still constant surface temperature for the sphere would cohere with the internal input also still being the same, is wrong? And explain them why? Somewhere. Anywhere?
Why is it never discussed how much the internal power to the sphere will or could be reduced or how much warmer the sphere will need to be if it isn’t, but rather kept constant, with so and so many shells surrounding it, absorptive shells or reflecting shells? Why don’t we see such a problem posed? Anywhere. Ever. Why does this claimed effect of yours remain such an elusive, such a total non-subject, apparently completely uninteresting to even mention in passing, by engineers and physicists alike?
You know why? Because it doesn’t exist. Because it’s not a physical thing. The shell cannot across a vacuum heat a blackbody sphere at its core whose surface is heated by a constant internal power source, beyond this input. Because the ‘back radiation’ is NOT extra HEAT. It originally comes from the sphere itself, emitted as heat loss. Letting heat loss turn into heat GAIN for the originally emitting object is letting the object be its own heat source.
The shell can only reduce final heat loss to space (Q –> Q”) by splitting Q from the planet in half (two sides), Q = Q’ + Q”. It cannot touch Q itself. Q’ and Q” are both Q/2. Q’ sets a limit to the maximum (equilibrated) temperature to which the sphere can possibly heat the shell. Q” is a function of this limit.
All the shell can do is reduce radiative cooling of the sphere when and if the sphere is ACTUALLY cooling (which as a blackbody it won’t be – once you shut off its internal power input, the last bit of energy escapes it as emitted radiation never to be replaced and the temperature drops directly from 290 to 0 K, because there is no thermal mass and perfect conductivity).
Insulation reduces COOLING RATES. Or increases HEATING RATES. Or decreases heating rates. It does not however, under any circumstances, raise the theoretical input temperature of the insulated object. That’s an outrageous idea! That’s like saying that if you could perfectly focus the solar rays with a magnifying glass so that the focus area becomes 100% as hot as the surface of the Sun itself (the absolute limit for focusing efficiency), then you could just insulate it in some SW- and NIR-transparent but FIR-opaque material and make it even hotter. Or better yet, just point an oven at the area and it will surpass the temperature of the Sun. Well, you don’t even need that. The atmosphere surrounding your focussing area is itself warmer than the vacuum of space around the Sun. So the area should upon perfect focus already be able to surpass the surface temperature of our star.
Let us get this sorted out, once and for all. Why doesn’t Spencer (or any of you) explain exactly how the ‘back radiation’ from the cooler shell is NOT raising the warmer sphere’s temperature by increasing its HEAT GAIN, but rather by reducing its HEAT LOSS? How does it accomplish this without actually transferring HEAT to the sphere, a positive inward transfer of ‘thermal energy’? After all, the heat loss flux balancing the internal heat gain isn’t restricted or disallowed. The constant internal power source in itself provides the same input to the surface as before, in itself producing the same potential surface temperature, in itself inducing the same, S-B-dictated emitted flux. All that changes in this setup is after all the ‘incoming’ back radiation flux. Are you for real then calling this an additional HEAT flux? I’m sure you are. Because you’re not subtracting fluxes, are you? You’re adding. To gain a larger outgoing flux from the sphere’s surface. Like F. Engelbeen stated it: J + J1.
So you’re hiding cleverly behind what appears to be a non-2nd-law-violating statement that the shell helps making the sphere warmer not by providing extra HEAT to it (’cause that would be absurd, right?), but rather by reducing its heat LOSS. But what you’re actually saying is indeed the HEAT thing. You in effect turn the cooler shell into a second independent HEAT source for the warmer sphere’s surface.
Gary Hladik says, May 3, 2013 at 3:17 pm:
“Kristian says (May 2, 2013 at 10:51 pm): “Reduce the heat loss and the thermocouple comes CLOSER to measure the REAL temperature of the gas.”
Interesting. So adding a radiation shield does nothing to the temperature of a radiating sphere, but adding a radiation shield DOES affect the temperature of a radiating thermocouple. And Kristian writes this with a straight face???”
You simply do not get it, do you? Once again you simply do not read what I write. (BTW, you saw the thing about the thermocouple setup being in a medium, not in a vacuum, right? Clue: convective heat loss.)
Kristian says …
1) “Why is it never discussed … ”
Undergraduate physics books don’t often address this specific case because it is a rather specialized case.
Engineering texts don’t often discuss this specific case because practical applications usually involve convection and conduction as well.
But astronomy texts (including one linked to above) and climate texts do discuss it. Google (one-layer greenhouse effect model) and you will get over a million hits of people discussing this.
2) You are arguing semantics for the most part when you discuss “heat”. While the word is often confusing, the actual physic is not unclear (and unfortuantely, “heat” is used colloquially in several different meanings in different contexts, which can add to the semantic confusion).
You ask for an explanation. First, read a good thermodynamics text until you understand that “heat” (in the technical thermodynamics sense) is the NET transfer of energy from warm to cool. That will clarify much of the ideas that you are trying to grasp and prevent you from incorrectly assuming that we would think things like “Are you for real then calling this an additional HEAT flux?”. Until you talk “the same language” of physics that we do, you won’t understand what we are saying, or be able to explain to us what you are thinking.
3) “That’s like saying that if you could perfectly focus the solar rays …”
This is actually some of the best, most interesting physics you have discussed. The maximum temperature in this case is the temperature of the hottest object providing the thermal energy. So with sunlight from a 5800 K, the hottest theoretical temperature WOULD be 5800 K.
But the heaters here are not limited to 288 K, but rather limited to 400 W/m^2. From an engineering standpoint, this is not possible at all temperatures, but we could, for example, use a 400 W light bulb, where the limiting temperature would be ~ 3000 K. The “theoretical input temperature” (as you call it) is ~ 3000 K, not 288 K. This would effectively limit the planet’s surface to 3000K no matter how may layers you added if you used light bulbs as the heaters.
But of course, this is not an issue for our planet, with temperatures an order of magnitude cooler.
4) To make a couple analogies, you seem to be thinking (among other errors) of the heater as a ….
* a constant voltage source rather than a constant current source. A constant voltage source can only charge a capacitor to a fixed voltage. A constant current source can charge it to any voltage (until you hit engineering limits of the devices).
* a constant pressure air pump rather than a constant volume air pump. A constant pressure pump can only fill a tank to a fixed pressure. A constant volume pump can fill it to any pressure (until you hit engineering limits of the devices).
Kristian says:
Absolutely untrue. You just keep finding excuses to ignore them. I have given you three examples, two being qualitative discussions of global warming in two of the most commonly-used intro physics textbook and one being a quantitative discussion of global warming involving exactly that shell model in what is one of the most (if not the most) commonly-used textbook for a first upper-level physics majors course in thermal physics: http://books.google.com/books?id=c0R79nyOoNMC&pg=115#v=onepage&q&f=false
To be fair, I’ll admit that this sort of example is not discussed as often as it ought to be. I think the reason for that is largely that they tend to take the problem through to a certain point and then assume that once they have explained (for example) how multi-layer insulation reduces heat transfer, you could use that result to calculate steady-state temperatures given some situation. But, it really should get more attention, if for no other reason than to disabuse people of incorrect notions that they might have about what the Second Law says.
http://books.google.com/books?id=c0R79nyOoNMC&pg=115#v=onepage&q&f=false [Hint: Repeating a false claim over and over again does not make it truer.]
There is no such thing as a “theoretical input temperature” unless the object is being controlled by a heater that automatically adjusts the power it supplies to maintain a certain temperature. The temperature of an object is determined by the balance of the energy coming in and the energy going out and no amount of bluster from you will change that fact.
You believe in what Robert G Brown (another PhD physicist) sarcastically calls “the Postma statement of the second law of thermodynamics, which is ‘Cold objects can never ever make warm objects change their temperature in any way, regardless of what else is going on.’ ” ( http://www.drroyspencer.com/2013/04/how-can-home-insulation-keep-your-house-warmer-when-it-cools-your-house/#comment-75875 ) However, as us physicists know, the Postma statement of the Second Law is a complete fiction. It has absolutely no basis in physics.
Yes, it is actually rather instructive to look at exactly this question: Why could we never make the “radiative insulation” so good that the Earth gets hotter than the sun? The answer is much more interesting and creative than the sort of arbitrary and capricious laws of nature that you imagine: The reason is simply that what the greenhouse effect is relying upon is the atmosphere selectively blocking the terrestrial radiation and not the solar radiation. However, as the Earth gets warmer and warmer, its spectrum shifts closer and closer to the spectrum of the sun and so such selectivity becomes impossible! [You might think that you could still make it work by, say, having the Earth have a higher absorptivity than the sun does. But, then Kirchhoff’s Law of Thermal Radiation ( http://en.wikipedia.org/wiki/Kirchhoff%27s_law_of_thermal_radiation ) tells you that the material that absorbs more at a certain wavelength also emits more at that wavelength.]
It accomplishes it just as you said…by reducing its heat loss (at a fixed temperature), so that it must increase its temperature in order to again be in radiative balance where it is emitting as much heat as it is absorbing. Again, you are invoking the Postma statement of the 2nd Law rather than the actual 2nd Law. The actual statement of the 2nd Law says that heat (the net energy flow) must be from the hotter object to the colder object. And, indeed it is, since you will see when you do the calculation that the radiative emission from the object to the shell is greater than the radiative emission from the shell to the object. Hence, the net flow of energy, or the heat, is from the hotter object to the colder object.
What we are doing is applying the real 2nd Law of Thermodynamics to the problem rather than the Imaginery 2nd Law of Thermodynamics because the real 2nd Law is the one that has been confirmed by countless experiments and is also understood to derive from more basic microscopic considerations through statistical mechanics. The Imaginary 2nd Law is an invention of people who want to fool you…and seem to be doing a pretty good job of it!
Just as an after-thought, I think this is a good general rule when dealing with heat flow problems: The Second Law is never really a rule that you have to apply in an arbitrary and capricious manner. It is simply something that will naturally be obeyed if you use correct physics along the way: The increase in radiative emission with temperature, together with Kirchhoff’s Law of Radiation ( http://en.wikipedia.org/wiki/Kirchhoff%27s_law_of_thermal_radiation ) guarantees that the 2nd Law will be obeyed. If you find yourself enforcing it independently, then you are probably enforcing some version of the Imaginary Second Law of Thermodynamics rather than the real Law of Thermodynamics.
Nobody has a problem with increasing radiative emission with temperature as per Stefan-Boltzmann, nor is there a problem with Kirchhoff’s Law.
The problem, and violation of rationality and transition to religion, is with the claim that a colder object’s radiation will cause a temperature increase in a warmer object, by whatever semantical argumentative method is invented to pretend such an idea such as back-radiation, or self-heating, or simply slowed-cooling etc. An object held at a constant temperature with a constant input with 100% efficiency in converting input power into thermal kinetic energy will not be further heated (i.e. its temperature caused to increase) by the radiation from a colder object placed in the vicinity. Rather obviously, the cooler object simply becomes heated (i.e. temperature caused to increase) by the constant-input, warmer, source. Just as you can not create higher than the solar spectral temperature when focusing sunlight, even if you “insulate it and prevent heat loss”, likewise you can not take a 255K spectral source and cause it to heat itself with its own spectrum beyond the spectrum that it is. The 255K spectral source has nothing to do with the solar spectral input (n.b. they are different spectra…) and so in no way can it be thought to be amplifying or re-condensing the solar spectrum to a potential of its temperature, such as with a magnifying glass.
Joseph says: “An object held at a constant temperature with a constant input … “
So which is it — constant temperature or constant power input? This is like saying “I have a power supply that provides a constant voltage and a constant current” or “I have a pump that pumps water at a constant pressure and flow rate”. As long as the load doesn’t change, then both can be true. But when the load changes then one (or both) of the parameters MUST change.
If the temperature is constant, then the power input will vary depending on the surroundings.
If the power input is constant, then the temperature will vary depending on the surroundings.
You are quite correct that if the heater is set to a constant TEMPERATURE, then no amount insulation or back-radiation will warm the object above the temperature of the heater. But this scenario (and the earth as well) does not have a constant temperature for the heater. The “shell models” have heaters that (within engineering limits that are not being tested) hold a constant POWER, so that the temperature adjusts according to the surroundings — which includes IR from nearby objects. The earth has that 5800 K input (NOT 255 K or 303 K or 322 k or 361 K or 394 K or any similar temperature that someone might try) we are talking about, so (in principle), the sun could warm an object to 5800 K. Of course the earth never gets to temperatures like that because it is insulated poorly and the sunlight is rather spread out. But having the sun provide some energy and the nearby objects providing other energy — both of which get absorbed by the earth — does not violate the 2nd Law of Thermodynamics in the least.
A bare, blackbody planet with 400 W/m^2 heaters will be 288 K (to use the numbers discussed up-thread). If you change the surroundings by adding a blackbody shell, then you can either …
* keep the TEMPERATURE constant @ur momisugly 288 K, but lower the power to 200 W/m^2
* keep the the POWER constant @ur momisugly 400 W/m^2, but raise the temperature to 345 K.
(The real earth is, of course, much more complicated due to atmosphere, rotation, variable emissivity, variable albedo …. But none of that changes the fact that IR radiation from other objects (even colder ones) can help raise the temperature of an object with an independent, constant power source.)
Folkerts asked: “So which is it — constant temperature or constant power input?”
A constant power input which creates a constant temperature with 100% efficiency in converting input power to thermal kinetic energy. When a cooler object is brought near this constant power input, constant temperature source, the cooler object will be warmed. The warming of the cooler object and the presence of the cooler object does not require the warmer source to have to heat up – the warmer source simply heats up the cooler object. The source has no knowledge to adjust itself to be cooler – it just holds the temperature it has with the constant input it has, and thus warms up cooler objects. IR radiation from a colder object does not warm up a warmer object – the warmer object simply warms the cooler.
The Solar energy at the distance of the Earth can only heat an object to the solar spectral temperature (5800 K) if the solar energy is re-condensed, i.e. focused with a magnifying glass or mirror. GHG’s do not perform this function, even in the case of the terrestrial radiation, and so the analogies here are moot. All we get here at the Earth is direct solar heating at the flux density it arrives at and then is attenuated to (equivalent to +121C [raw] at maximum under the Sun, but distributed as the cosine function over a hemisphere and with albedo attenuation), followed by redistribution of that heat and high-temperature forcing by water and atmosphere and cooling at night time.
Joel Shore, it seems to me that capriciousness is in saying that a source will know to power itself down in order to hold a constant temperature because it is wished that radiation from a cold object can heat up a warmer object. There is nothing arbitrary about the fact that a colder object never warms up a warmer object – that is a very consistent rule. In conduction it never happens, and likewise in radiation it doesn’t happen. This is elegant and beautiful because the classical laws of thermodynamics and statistical mechanics are universally applicable even among different modes of physics (matter/conduction & photons/radiation). I say that cold things never heat up hotter things either by conduction or by radiation because such a rule is consistent and truthful; there is nothing arbitrary or capricious about stating and applying such a rule. Kristian has done just a brilliant job explaining how the physics actually works, for example. I’ll have more on these concerns and the related questions and physics in a future blog post.
Joseph: Did you ever take a course in statistical physics? It seems strange that someone with a background in astrophysics wouldn’t and yet it seems even stranger that someone who did would write what you just did in your post.
You are teaching people to think that physics (and thermodynamics in particular) is some set of arbitrary and capricious laws when it is actually elegant and beautiful. And, you are doing this for what purpose?
Kristian says:
May 6, 2013 at 9:58 am
Gary Hladik says, May 3, 2013 at 3:17 pm:
“Kristian says (May 2, 2013 at 10:51 pm): “Reduce the heat loss and the thermocouple comes CLOSER to measure the REAL temperature of the gas.”
Interesting. So adding a radiation shield does nothing to the temperature of a radiating sphere, but adding a radiation shield DOES affect the temperature of a radiating thermocouple. And Kristian writes this with a straight face???”
You simply do not get it, do you? Once again you simply do not read what I write. (BTW, you saw the thing about the thermocouple setup being in a medium, not in a vacuum, right? Clue: convective heat loss.)
That would be convective heating of the thermocouple and radiative heat exchange with the shield.
Folkerts asked: “So which is it — constant temperature or constant power input?”
A constant power input which creates a constant temperature with 100% efficiency in converting input power to thermal kinetic energy. When a cooler object is brought near this constant power input, constant temperature source, the cooler object will be warmed. The warming of the cooler object and the presence of the cooler object does not require the warmer source to have to heat up – the warmer source simply heats up the cooler object. The source has no knowledge to adjust itself to be cooler – it just holds the temperature it has with the constant input it has, and thus warms up cooler objects. IR radiation from a colder object does not warm up a warmer object – the warmer object simply warms the cooler.
The Solar energy at the distance of the Earth can only heat an object to the solar spectral temperature (5800 K) if the solar energy is re-condensed, i.e. focused with a magnifying glass or mirror. GHG’s do not perform this function, even in the case of the terrestrial radiation, and so the analogies here are moot. All we get here at the Earth is direct solar heating at the flux density it arrives at and then is attenuated to (equivalent to +121C [raw] at maximum under the Sun, but distributed as the cosine function over a hemisphere and with albedo attenuation), followed by redistribution of that heat and high-temperature forcing by water and atmosphere and cooling at night time.
Joel Shore, it seems to me that capriciousness is in saying that a source will know to power itself down in order to hold a constant temperature because it is wished that radiation from a cold object can heat up a warmer object. There is nothing arbitrary about the fact that a colder object never warms up a warmer object – that is a very consistent rule. In conduction it never happens, and likewise in radiation it doesn’t happen. This is elegant and beautiful because the classical laws of thermodynamics and statistical mechanics are universally applicable even among different modes of physics (matter/conduction & photons/radiation). I say that cold things never heat up hotter things either by conduction or by radiation because such a rule is consistent and truthful; there is nothing arbitrary or capricious about stating and applying such a rule. Kristian has done just a brilliant job explaining how the physics actually works, for example. I’ll have more on these concerns and the related questions and physics in a future blog post.
joeldshore says:
May 6, 2013 at 6:06 am
“But, the net effect of adding greenhouse gases is a warming of the troposphere.”
——————————————————————————————————-
Joel,
No, you are still not getting it. Pierrehumbert realised what the problem was. Without radiative gases, convective circulation would cease and the stagnated warm poorly radiative gases at altitude would super heat due to limited absorption of IR and UV. Average tropospheric temperatures would be so much hotter than present that we would probably lose most of our atmosphere to space. This is why he cooked up the “radiative gases cause cooling but after a “certain” concentration they cause warming” bafflegab.
The net effect of radiative gases is cooling of the atmosphere. I have shown this by empirical experiment. To make the AGW hypothesis pig fly, Pierrehumbert tried to change this to “The net effect of adding radiative gases to the atmosphere is initially cooling, but after a magical point that just happens to coincided with current politics, it causes warming.”
Joel, I will ask you directly –
A. Do you support Pierrehumberts 1995 claims?
B. Is there any other scientist you are aware of making such claims before 1990?
And, we see in Joseph’s latest post the usual sophistries of the Sl*yers:
(1) According to the Sl*yer’s, temperature is determined by the rate of energy in; the rate of energy out doesn’t matter. Insulation doesn’t exist.
(2) They always talk about “the fact that a colder object never warms up a warmer object”, but never define their terms. So, one can’t accuse them of being wrong: It is indeed true in a sense that the colder atmosphere does not warm the Earth; the net flow is from the Earth to the atmosphere. The sun warms the Earth…but the atmosphere influences the rate at which energy leaves the Earth (for a given Earth temperature) and hence what temperature the Earth must be at in order for there to be balance between the energy it receives from the sun and the energy it radiates back out into space.
Really, so insulation doesn’t exist? So, at the microscopic level, if you have a temperature gradient in, say, a gas (higher on the left and lower on the right) then in any collision between molecules, the energy transfer is always to the right?
It is not elegant at all. It posits bizarre rules that there is no way to enforce on the microscopic scale. It relegates thermodynamics from a beautiful explanation of how the statistics of many particles can lead from symmetry in time on the microscopic scale to asymmetry on the macroscopic scale to a bunch of arbitrary and capricious laws on the microscopic scale. And, worst of all, it’s wrong.
Shore said: “According to the Sl*yer’s, temperature is determined by the rate of energy in; the rate of energy out doesn’t matter. Insulation doesn’t exist.”
Insulation keeps a space warm by preventing, typically, draft losses, air leaks, and reducing conductive and convective loss. Insulation does not make the source itself warmer, but allows a space the much hotter source is warming, to be warmer, because you’re trapping the warm gas instead of letting it escape. The atmosphere does this by a different process because N2 and O2 have zero emissivity, and also latent heat release from water/vapour keeps much of the planet warmer than otherwise. In the GHE, however, the source-induced temperature actually has to be amplified by some process, because the source is incorrectly treated as 240 W/m^2, and so a self-warming mechanism is created based on this incorrect initial assumption, that amplifies 240 W/m^2 input to a higher temperature than 240 W/m^2 can actually create. But as we all know by now, 240 W/m^2 is not the actual input, and the actual input is much hotter and creates much warmer temperatures than 255K and drives far more energetic processes than 240 W/m^2 could ever create. On Earth, the loss rate is equal to the input rate, and this can only equate to a higher temperature than the averaged input if the emissivity is low, which is a result of N2 and O2.
Temperature is actually determined by the total content of energy within a mass. Equilibrium is reached when the input equals the output, and in all conductive cases the mass receiving energy cannot be made a higher temperature than the input. We cannot conduct a higher temperature into a target than the temperature the source is. It can happen radiatively only when the emissivity is less than the albedo, but low-emissivity induced higher temperatures (such as you will get with O2 and N2) are not a GHE. If all things are equal, say, an assumed 240 W/m^2 fully absorbed input and an output emissivity of unity, then 240 W/m^2 can never create a temperature higher than 255K, even with as much insulation as you want. Only low emissivity can turn 240 W/m^2 into an induced temperature warmer than 255K. Of course on Earth, we also have water and latent heat holding things warmer and also the natural lapse rate distribution of temperature in the atmosphere which dictates that the bottom of the atmosphere has to be warmer than the top, and thus with the average in the middle (255K), and independent of the presence of any GHG’s. In fact, when the supposed GHG water vapour is present, average surface temperatures are lower, not higher.
Shore said: “They always talk about “the fact that a colder object never warms up a warmer object”, but never define their terms.”
Those terms are very well defined. A colder object has a lower temperature than a warmer object. A warmer object has a higher temperature than a colder object. A colder object never heats up a warmer object. A warmer object generally heats up a colder object. This is all very clear and concise.
Shore said: “the atmosphere influences the rate at which energy leaves the Earth (for a given Earth temperature) and hence what temperature the Earth must be at in order for there to be balance between the energy it receives from the sun and the energy it radiates back out into space.”
The atmosphere can only influence the rate at which energy leaves the Earth if it has lower emissivity than the albedo (or less than 1 emissivity with the albedo-corrected value of 240 W/m^2 for the input). It is non-GHG’s which supply the low, less than unity, emissivity. This means the atmosphere will hold a higher temperature than it would if emissivity were actually unity. Also we have constant latent heat release preventing the temperature from dropping too low overnight which also results in a higher average diurnal temperature than there would have been otherwise.
Shore said: “So, at the microscopic level, if you have a temperature gradient in, say, a gas (higher on the left and lower on the right) then in any collision between molecules, the energy transfer is always to the right?”
Heat transfer is from hot to cold, in this example from left to right. Individual gas molecules can bounce from right to left (cold side to hot side), but this is never considered as back-conduction heating or as causing a general increase in temperature on the hotter side. Or if two solid surfaces were brought into contact, one cold and one hot, the colder surface would be “bouncing” (at the molecular level) against the warmer surface, but this would not heat the warmer surface because the heat flow is from hot to cold only – the warmer surface is more energetic, just as the warmer gas is more energetic. The heat flow is from hot to cold, meaning that the cold side rises in temperature; this does not mean the hot side also rises in temperature, the hot side simply warms up the cold side. Net heat or net energy flow from hot to cold means that the cold side warms up; any energy flow from cold to hot does not manifest as heating (general temperature increase) on the warm side because there is always more energy flowing from hot to cold. Net heating means that heating, temperature increase, is one way, meaning that temperature only rises in one direction, even if energy flow may be two-way. It does not mean that the cold side heats up the hot side and that the hot side heats up the cold side simultaneously, just as long as more heating is occurring from hot to cold – That’s a capricious and arbitrary and even sophistic reinterpretation of such thermodynamics, and is bizarre and inelegant. Statistical mechanics proves that any symmetry on the microscopic scale (such as a “cold-side” molecule bouncing in the “hot-side” direction) are always outweighed by the majority of the asymmetric transfers of energy or energy flow from higher energy states (high temperature) to lower energy states (low temperature). During thermal interaction there is no possible general increase in the warmer side’s higher energy states (higher temperature) being caused by the cooler side’s lower energy states, simply because such a thing is essentially statistically impossible.
@ur momisugly Joel
No sceptic every bought into the PSI crud. Appearing to fight it is just a waste of everyone’s time.
Konrad, I empathize with your conclusion, but think it is worth at least occasionally fighting the “PSI crud” (and not everything they say is “crud”, but unfortunately just enough is to “be dangerous”).
1) The PSI people are skeptics, so at least SOME skeptics agree with PSI.
2) There is the idea that “a stitch in time saves nine”. If left completely unchecked, bad physics can easily spread among those who are not really trained in physics. Just like skeptics are valuable for pointing out the follies of the more outrageous alarmists, physicists are valuable for for pointing out the follies of the more outrageous PSI proponents.
Konrad: I would have to read Pierrehumbert’s paper in more detail before having a strong opinion, but as I have noted below, an atmosphere with no ability to radiate is a bizarre singular limit and, in such a limit, it might be possible that there would be some strange things like a discontinuity between the temperature of the surface and the temperature of the atmosphere.
However, two things that we do know are the following:
(1) The surface temperature of the Earth in the limit of removing greenhouse gases has to go to the colder temperature that is required by radiative balance (255 K assuming unchanged albedo from the current state). As greenhouse gases are added, the surface warms.
(2) In the current situation, addition of greenhouse gases warm the lower atmosphere. Claiming this is not true is really not that much different than making the claim that the Sl*yers do: To believe otherwise goes against all understanding and calculations of radiative and convective processes in the atmosphere that are well-confirmed by the entire field of remote sensing.
Joseph Postma says:
No..In the case of more than two objects, your terminology becomes unclear. There is no debate in the case of two objects interacting with no other heat inputs. The question that comes up is when we now have 3 objects (sun, Earth, atmosphere). Everyone agrees on the following:
(1) Heat (net macroscopic energy flow) is always from hot to cold.
(2) With two objects radiative interacting and no other sources of energy (from a third object or a conversion of some other form of energy into heat), the warm object will cool and the cool object will warm.
Where things get imprecise is when we have 3 objects, sun, Earth, and atmosphere. You then try to characterize any change in the atmosphere that causes an increase in the temperature of the Earth as being a colder object heating a warmer object. However, that is a misleading use of terminology: The heat is flowing from the sun to the Earth to the atmosphere, so the atmosphere is not heating up the warmer object. The sun is heating up the Earth. However, in the presence of an IR-absorbing atmosphere, the sun is able to heat up the Earth to a higher temperature because the temperature of the Earth is determined by that temperature necessary for there to be a balance between the heat it absorbs and emits.
Simple example that I could give to intro physics students: Let’s say we have an insulated aluminum rod, 10 cm long, 1 cm^2 cross-sectional area, so it’s a 1-D conduction problem. You attach the left end of the rod to a heater that puts energy into the rod at the constant rate of 10 W/m^2. The other end of the rod, you attach to a piece of dry ice fixed at -78 C. The question is: What is the steady-state temperature of the left end of the rod? Now, take the right end of the rod and attach it to just a regular piece of ice (T = 0 C) instead of dry ice. Is the steady-state temperature of the left end of the rod change from what you found before?
This entire argument of yours is a complete strawman and I think you know it. We don’t disagree on what happens for the energy transfer between any two objects at different temperatures (and the resulting change in temperature of the two objects if this is the only thing going on).
The point that you are trying to argue, rather, is that the rate of heat flow between two objects is completely unrelated to the temperature difference between them. (Of course, you never make this claim directly because people would see right through it, but both of us know that mathematically that is the only way that you could possibly be correct.)
Shore said: “There is no debate in the case of two objects interacting with no other heat inputs.”
Glad you agree that cold things do not heat up warmer things. The presence of any number of objects of course does not change this thermodynamic law. If there is a third object which we can think of as an insulating layer, then the insulating layer can only come to the same temperature as the 2nd object which is being heated by the 1st object input, because the source of heat for the 3rd object insulating layer is the 2nd object, not the 1st object source (the 3rd object insulating layer doesn’t interact with the 1st object source; its heat source is the 2nd object). If the insulating layer however reduces the emissivity of the surface of the 2nd object, then only in this case will higher temperatures than the input be achieved for the 2nd object.
Shore said: “You then try to characterize any change in the atmosphere that causes an increase in the temperature of the Earth as being a colder object heating a warmer object.”
That’s not what I say, that is what arguments for backradiation heating say. I agree that you are pointing out that it is an incorrect argument and statement of the problem. The colder atmosphere does not heat the surface with backradiation. This has been our position all along. So now that backradiation heating has actually been acknowledged as a wrong statement, hopefully other GHE advocates will stop using that argument, such that cold can heat hot while hot heats cold because the cold radiation has to be emitted, has to be absorbed, and thus has to cause heating on a warmer object, as long as more warming occurs on the colder object then both the hotter and colder object can become heated, which is of course wrong and sophistic. The cold-source backradiation does not cause the heating.
It would be helpful if you told the back-radiation heater people to stop spreading false physics – you might imagine it becomes difficult to have to track and argue against all of these conflicting theories on what the GHE actually is and how it actually functions. We also have people saying that it is in the raising of the mean radiating level which creates more depth for adiabatic heating which is the GHE, and this is still different from your current argument and the backradiation heating argument. The argument you are using now is that reducing emission from the surface results in a higher surface temperature. This would be true if the reduction in the ability to emit was caused by lowering the emissivity.
Shore said: “The heat is flowing from the sun to the Earth to the atmosphere, so the atmosphere is not heating up the warmer object. The sun is heating up the Earth. However, in the presence of an IR-absorbing atmosphere, the sun is able to heat up the Earth to a higher temperature because the temperature of the Earth is determined by that temperature necessary for there to be a balance between the heat it absorbs and emits.”
And this then returns to the idea that the colder atmosphere causes a warmer surface to become warmer still than the input. But of course, you cannot insulate something to be warmer than the actual input, and in the GHE the input is only 240W/m^2 or 255K. Insulating a 240W/m^2 or 255K input cannot create a higher temperature than 255K; only reducing the emissivity can. Arguments then turn to discussing the spectral temperature of incoming sunlight and focusing it with a magnifying glass which can produce extremely high temperatures, but this of course has nothing to do with GHG’s because they do not magnify the incoming solar spectrum and so that discussion is a red herring. GHG’s interact with the terrestrial output in their GHE function, and they don’t even magnify that radiation, and, if they did, it is acknowledged that they wouldn’t create a warmer temperature than the terrestrial radiation spectral temperature in any case because the spectral temperature sets the limit. Hence, GHG’s can’t raise the temperature above the spectral source and thus the spectral source, the surface temperature, has to have its own cause.
In order for the improved insulation/reduced radiative loss from the surface to actually cause an increase in global temperature at the surface, requires that sunshine no longer be treated at 240 W/m^2 or 255K but as its actual incoming real-time value; the problem here for GHE orthodoxy is that with real-time high-temperature forcing from the Sun acknowledged, we suddenly have all sorts of high-energy, high-temperature phenomena occurring and being produced that the 255K input framework could never produce – not without that framework’s invention of a GHE. So, this is why real-time high-temperature input power from the Sun is never acknowledged, because such a physical fact is always detrimental to GHE orthodoxy and makes it fall apart. Real-time high-power high-temperature input from the Sun can do all sorts of things by itself and on its own that 240 W/m^2 could never do on its own; hence, other stuff needs to be invented to augment the 240 W/m^2 255K framework in order to make it mimic what the Sun is actually doing all by itself. The stuff that is invented is backradiation heating & etc., in general, the GHE.
That aluminum rod problem is not really relevant to an atmosphere whose majority components have near-zero emissivity. You can also use that problem with a constant input and consider what happens if the other end of the bar has unit emissivity or near-zero emissivity. You attach the left end of the rod to a heater that puts energy into the rod at the constant rate of 10 W/m^2. The outer cylinder of the rod is perfectly insulated against any heat or energy loss. The other end of the rod has the same surface area as the input side (0.01 m^2) and has unit emissivity and can radiate freely to outer-space. Then solve the problem with the other end of the rod having an emissivity of 0.1. This is much more like the atmospheric problem because of the low emissivity of the atmosphere which results in a higher temperature than with unit emissivity.
Shore said: “The point that you are trying to argue, rather, is that the rate of heat flow between two objects is completely unrelated to the temperature difference between them.”
Nowhere have I stated such a thing or argued that. I’m not going to defend statements that I never made. I have always stated that heat flow rate is proportional to the temperature difference. Please do not create strawman arguments by putting words into other people’s mouths. My own statement which you called a strawman is a statement of fact and it applies with any number of objects and any sources and sinks of heat – it is statistically impossible for cold to heat hot in any combination of sources and sinks. If you agreed with my statement then there is no reason to call it a strawman. Your aluminum rod discussion is a proper red herring however because it doesn’t actually bear on the atmosphere…the atmosphere and heat flow within it doesn’t behave like or have the same properties as an aluminum rod, nor is heating constant, nor is the top of the atmosphere held fixed at different temperatures. In fact, GHE orthodoxy usually says that the top of the atmosphere gets colder with more GHG’s, meaning that the bottom of the atmosphere will be cooler too for the same rate of energy flow as per the way you set up the aluminum rod example. My modification of your aluminum rod example is an improvement and fix to it, but it becomes apparent that low emissivity of bulk-quantity gases are more relevant to holding higher temperatures than trace gases with high emissivity. Of course, when the “GHG” water vapour is present, cooler average temperatures are observed, not warmer. And of course, with nearly a 100% increase in atmospheric CO2 levels, the atmosphere and surface is still actually the same temperature and even significantly cooler than past warming cycles which had much less atmospheric CO2, and so the postulated effect of GHE warming by whatever method is argued is simply non-existent in reality. A 100% increase in CO2 levels has not produced a statistically significant signal of warming beyond past climate variations.
joeldshore says:
May 7, 2013 at 7:40 am
———————————————————————————-
Joel,
As I have clearly stated many times before radiative gases do heat moving gases (temporarily) near the surface by intercepting surface IR. IR emission from these gases can slow the cooling of land surface. However for a moving atmosphere, surface to atmosphere radiative exchange is largely irrelevant for average tropospheric temperatures. IR radiation to space at altitude has a far more significant effect on temperatures.
Have a look at a standard NASA atmospheric energy budget cartoon. While there are many inaccuracies in the figures, they are workable. The net energy gained by the atmosphere by intercepting both surface IR and solar UV/SW/IR is less than half of the energy the atmosphere is emitting as IR to space. Even without taking convective circulation into account, the net effect of radiative gases in our atmosphere is cooling.
If a gas column in a gravity field is maintaining a stable temperature but exhibiting strong vertical convection then it can mean only one thing. Energy is flowing through the gas and energy must be entering the gas at a lower point than it is exiting. The speed of the convective circulation depends on the energy imbalance between low and high altitude. Radiative gases add to the net energy entering the lower atmosphere and do over twice that work emitting energy to space at higher altitude. Adding radiative gases to a moving atmosphere simply increases the energy imbalance between low and high altitude and therefore speeds up convective circulation.
Radiative gases cool the atmosphere by IR emission to space at altitude. The net effect of radiative gases on lower atmospheric temperatures is also cooling as these gases are critical for tropospheric convective circulation. To understand this, this image of developing convective circulation in a fluid should help –
http://wattsupwiththat.files.wordpress.com/2013/02/rayleigh-benard-circulation.jpg
– Look at the average near surface temperatures at 4s before breakaway occurs, then at 5s when circulation is established.
You may claim that “an atmosphere with no ability to radiate is a bizarre singular limit”, but it should be clear that I have shown through empirical experiment that without radiative cooling at altitude the atmosphere would be far hotter. As radiative gases increase from 0%, the atmosphere cools and convective circulation develops. To claim that radiative gases heat a moving atmosphere, you would have to claim as Pierrehumbert does, that at first radiative gases cause cooling, but after a “certain point” they cause warming. Are you going to support Pierrehumbert’s pseudo science? How many ppm of water vapour would that be before cooling stops and warming begins?
There is no magical point at which radiative gases stop cooling and start warming. Radiative gases act to cool our atmosphere at all concentrations above 0.0ppm.
tjfolkerts says:
May 7, 2013 at 7:11 am
“The PSI people are skeptics”
—————————————————————-
Pull the other one, it has bells on 😉