Our WUWT thread on Antarctic Sea Ice Losses has spurred quite an interesting discussion. Dr. Robert G. Brown of the Physics Department at Duke University responds to a comment on ice albedo with a summary of water vapor action, the greenhouse effect, and the chaotic nature of the atmosphere. He ends with his view of why he’s not a betting man.
Well worth a read.
phlogiston: I do realise that over the Antarctic land mass albedo from surface snow is anomalously higher than that from cloud, since the snow presents such a pure white surface. However this is probably not the case for sea ice whose surface is more irregular and cracked with patches of dark sea in between.
The trouble is that water vapor is literally a two-edged sword. As vapor, it is the strongest greenhouse gas in the atmosphere by (IIRC) around an order of magnitude, so increasing water vapor can and does measurably increase the GHE — a lot, when considering dry air versus saturated air. In arid deserts, temperatures skyrocket during the day and plummet at night because of the absence of a water vapor driven GHE — CO_2 alone isn’t nearly enough to keep upward facing surfaces from rapidly losing their heat due to radiation. In very humid tropical climates, the nights are consistently warm because of the GHE.
However, water vapor is also the mediating agent for two major cooling mechanisms. One is the bulk transport of latent heat — sunlight and LWIR hit the sea surface and cause rapid evaporation of surface molecules of water. Wind blows over the ocean surface, stripping off water molecules as it goes. This evaporated water has a huge heat content relative to liquid water — the latent heat of vaporization. As the warm water vapor is carried aloft by convection, it carries the heat along with it. It also cools as it rides the adiabatic lapse rate upward, and further cools by radiating its heat content away (some of which returns to the Earth as GHE back radiation). Eventually the partial pressure of water vapor in the moist air becomes saturated relative to the temperature and the dew point is reached, making it comparatively probable that the water vapor will recondense into water. In order to do so, though, several things have to be “just right”. The water vapor has to be able to lose the latent heat of vaporization that it picked up at the water surface when it evaporated. The future water droplets have to be able to nucleate — which is a lot more likely to occur when there are ionic aerosols in the atmosphere as water (a polar molecule) is attracted to bare charge of either sign.
Once a water droplet is nucleated and grows past a critical size (that depends weakly on humidity and temperature) its surface becomes large enough that growth due to increased surface deposition outweighs loss due to surface evaporation, and the droplet stabilizes as a single droplet of condensation in a cloud or continues to grow to fall as rain. Either way the water, now high in the troposphere and hence through most of the optically opaque greenhouse layer, releases heat that is “short circuited” through the greenhouse mechanism and lost to space via radiation.
The cloud, as you note, has a very high albedo. High albedo means that it strongly reflects short-wave (e.g. visible) radiation without ever absorbing it and being heated by it. During the day, clouds outside of the polar regions act as a cooling agent, reflecting sunlight before it has a chance to reach the ground and lower troposphere to warm either one. During the day and the night, however, the cloud also acts as a powerful greenhouse blanket, directly reflecting LWIR as well as visible back down towards the Earth’s surface. In the tropics, daytime reflection wins by a landslide — reducing the incident sunlight by a huge fraction for a large fraction of the day beats the comparatively small modulation of surface radiative losses both day and night. In the temperate zone (again, IIRC) albedo still wins, but by a smaller and smaller margin as one creeps north (and in ways that are increasingly dependent on seasonal weather patterns — in the winter clouds can easily be net warming where in the summer they can be net cooling).
However — and this is key and the reason I’m replying to you — in the polar regions clouds are generally net warming, at least most of the year. You’ve already indicated some of the reasons — the polar regions are already often or permanently ice covered, and the gain in daytime albedo from clouds vs ice is not so great. The real problem, however, is that nighttime warming from the enhanced GHE from clouds scales with the fraction of the day that it is nighttime, and of course inside the arctic circles that can be as long as 100% of it. High albedo doesn’t cool when there is no incident sunlight to reflect, and even in the arctic summer, the sun comes in at a substantial angle so that direct solar warming is weak (so that clouds can reflect only a proportionally smaller amount of heat). A lot of polar temperature is determined by heat transport, not direct heating, explaining the substantial difference in mean temperatures of the North and South poles. In the north, there is substantial heat transport and heat exchange via the ocean; in central Antarctica there is only the atmosphere to carry heat in from the warmer latitudes and it just can’t do the job half as well.
That’s why I hesitated to assign a sign to the net feedback from any sort of local modulation of e.g. ocean-air humidity or sea ice coverage. The processes are COMPLEX and can have either sign, and they are NON-LOCAL as adding humidity in one place can increase albedo someplace else thousands of miles away is it finally concentrates enough to form clouds. A large part of the rain that falls over North Carolina comes up from the Gulf of Mexico maybe 1000 miles away. Some of it comes all the way over from the Pacific, where some of that might have originated in e.g. the growing El Nino. Heat from the tropical Pacific can be transported all the way to NC before it finally releases its heat and falls as rain, before it finally creates clouds that cause NC to cool after helping to greenhouse warm much of the surface area it crossed in between.
This is the kind of thing that the models are supposedly trying to model, but they perforce replace all of the small-length scale detail of this description with presumptive averages over cells 100-300 km square (where weather phenomena such as thunderstorms are order of 1 to 10 km square, where the details of front structure and development are much finer than this). They are excruciatingly tuned to aerosol levels and albedo — they have to be to stabilize anywhere near the correct/observed temperatures and preserve the central tenet that CO_2 causes X amount of baseline warming that is on average augmented by additional water vapor.
This last assumption is finally dying a quiet and well deserved death. AFAIK, it is due to Hansen, who in his original papers predicting disaster assumed universally positive water vapor feedback (and for no particularly scientifically motivated reason that I can see, hypothesized truly absurd levels of water vapor feedback that doubled or tripled the CO_2-only warming of his then very simple models). Naturally, some of the GCMs out there have built into them parametric assumptions that preserve this much “climate sensitivity” — total ACO_2 warming plus feedback, usually at the expense of an overdriven response to e.g. volcanic aerosols necessary to explain periods of global cooling and to keep the model from having a runaway exponential instability (because one has to have a mechanism that keeps positive feedback water vapor from causing increase of water vapor without bound just from FLUCTUATIONS in water vapor content or global temperature — the climate cannot be a biased random walk where every time the temperature goes up a bit, average water vapor increases and hence resets the Earth’s average temperature a bit higher unless a competing process can completely erase the gain when the temperature fluctuates down a bit).
At the moment, estimates of climate sensitivity are struggling to retain any net positive feedback from water vapor in the face of data that already solidly excludes the kind of absurd feedback levels Hansen originally hypothesized. Even the question of net negative feedback from water vapor, long considered to be anathema in climate science (except for a few mavericks who managed to publish papers suggesting that clouds could easily lead to net negative feedback through the dual mechanism of latent heat transport and modulation of albedo) is no longer completely off of the table. I don’t know that people will start to take it too seriously unless/until the Earth actually cools (several tenths of a degree, sustained, not just vary up or down or weakly downward trend) but obviously if this happened it would truly be the only likely catastrophe associated with global warming to all of those that have invested their professional careers, hundreds of billions of dollars of global wealth, and their political and/or scientific reputation on shaky claims in poor agreement (so far) with observational data.
IF there is a super-ENSO, perhaps it will help their arguments survive a bit longer, or perhaps it will truly kick up the temperature to where the models become believable again. Perhaps not. ENSO is not the only factor in climate evolution, and while it has been dominant for the last half century or so in mediating positive jumps as documented by Bob Tisdale, its ability to do so could easily be predicated by the phases and states of the other decadal oscillations, the state of the Sun, the state of baseline vulcanism, the immediate past climate history, and the price of tea in China. A chaotic nonlinear system can be quasiperiodic and apparently causal for a while and then for no computable reason change to an entirely different mode of behavior where a significant quasiparticle/process becomes insignificant and some other process becomes the critical driver. We could still watch as the developing ENSO discharges all that heat in such a way that it never manages to raise global average temperatures by much because of some confounding wave that causes the heat to be efficiently transported up and quickly lost rather than persisting to spread out over the globe at high altitude, or by a mere modulation of the winds that causes albedo over the warm(ing) patch to be higher than expected so that the delivery of solar energy to the ocean is effectively interrupted. It’s not like we can properly predict ENSO (although we can do pretty well with forward projective hindsight once an ENSO process has started).
No matter what, I expect the next year to be highly informative. If we have a super El Nino that heats the planet by 0.3C very rapidly, that certainly makes GCMs more, not less, plausible on average as it kicks global average temperatures at least in the right direction for them not to be as egregiously wrong as they currently appear to be. If it only kicks the temperature up by 0 to 0.1 C, and that only transiently so that temperature in a year are again pretty much flat relative to 1998-2000, it is very bad news for the models. If it fizzles altogether — short-circuited, perhaps, by the downhill side of solar cycle 24 that maybe be beginning and which will proceed with poorly predictable speed and which may or may not have a competitive local effect on the climate and produces no gain at all and cycles immediately into a cooling La Nina that augments any solar cycle cooling to actually drop global average temperatures, that too will be very informative.
Personally, I won’t even place a bet. I don’t think the climate is computable, which means that I think one is basically betting on the output of a (possibly biased) random number generator. I’d rather play Mumbledy-peg for money.
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I hope the mods will forgive me re-posting this:
I just wonder why someone needs multiple ids to push single belief system…
joelshore says:
Climate models “don’t fail ludicrously.”
They certainly do. Not one multi-million dollar GCM was able to predict that global warming would stop. There has been no global warming for 17+ years now. That is a total failure.
If models are any good, tell us when global warming will “resume”. You know, after the “pause”.
joeldshore’s opinions are always worth considering but they would carry more weight if he had spent some time refuting Gerhard Gerlich and Ralf D. Tscheuschner’s refutation of Halpern et al. (for which Professor Shore is part of et al) “Reply to “Comment on ‘Falsification Of The Atmospheric CO2 Greenhouse Effects Within The Frame Of Physics’ ” http://arxiv.org/abs/1012.0421 or http://www.skyfall.fr/wp-content/gerlich-reply-to-halpern.pdf
I may have missed something but I cannot see anywhere that Halpern et al have stepped up to the batting in the last three years.
From a computing perspective the answer is clear: No.
We’re dealing with a huge system that has a huge amount of variables and is essentially chaotic. There is no computer that can run this. The Earth Simulators that currently exist are cute, but nowhere near what they’d have to be.
I’m just trying to imagine the necessary hardware, not even trying to think of the programming that would have to go into this.
Computing it or even foretelling it over decades is not possible.
No sooner do I say “there is also a concerted effort, driven by ideology (and, in some cases, also economic interests) to discredit them through half-truths and falsehoods” than dbstealey stops by to illustrate this.
His claim that the models didn’t predict the pause is a good example of a half-truth at best:
(1) His “17+ years now” refers to some combination of cherry-picking data sets and defining no global warming as no statistically-significant global warming. Since, it takes at least a 8 or 10 years to establish statistical significance under the best of circumstances, the “no global warming” meme is a half-truth. It will always be true under any circumstances that there has been no statistically-significant global warming for N years where N is a value that will vary according to circumstance.
(2) His claim that no models predicted this is another example of a half-truth. Did models predict that this would occur at this particular interval of time? No, but that’s because such a prediction means that the models have to predict the actual realization of “noise” of internal variability, which is known to be extremely sensitive to initial conditions and hence not practically predictable. [It’s like saying that my statistical model can’t predict when I will get a particularly run of 6 heads in a row when I toss a fair coin, but that doesn’t mean the statistical model for such a coin toss is a failure at predicting the statistical behavior of the results. In fact, we know in this example that it is very successful.] However, the models do predict that, due to internal variability, there will be quite long periods of no upward linear trend (and, particularly, no statistically-significant upward linear trend) even when the models have a constant increase in the radiative forcing due to greenhouse gases.
These sort of half-truths explain the huge gulf on the issue of climate change that exists between the scientific community on the one hand and the community of naysayers like dbstealey on the other.
joeldshore says:
May 22, 2014 at 10:54 am
I’m not attacking science, I’m attacking the epically failed climate models, which are as far from science as it’s possible to get. They are the antithesis of science.
It’s preposterous to assert baselessly that they haven’t failed. Actual observations are below even the error bars of their predictions. The ideologically driven agenda is promoted by CACA activists mascaraing as scientists, playing them on Twitter rather than in real life.
No one has been more forward on this blog in exposing the lies of creationists, whose “science” is akin to that of CACA proponents. Name the lies & half truths which you suppose I’ve committed against the One True Religion of “climate science” which is the bizarro twin of genuine science.
CACA is going to do more damage to the reputation of science than eugenics & creation “science” put together in coming decades.
At least you have the honesty to recognize uncertainties in “climate science”. Unfortunately its fundamental article of faith, that the primary driver of earth’s climate system is CO2, is certainly false, as has repeatedly been shown by nature. Only a false religion could be founded upon such an easily demonstrated counter-factual premise.
My objections to the false religion of CACA isn’t ideological at all, but entirely scientific. For decades I’ve looked for even a shred of evidence in support of the unfounded assertion that most of whatever warming occurred in the 20th century was caused by human activity, but have found none. Please trot it out if you think you have some. Thanks.
And allow me to add that I too am glad you comment here.
Let’s see :
http://www.cpc.ncep.noaa.gov/products/analysis_monitoring/enso_update/olra-30d.gif
“””””…..
george e. smith says:
May 22, 2014 at 8:33 am
“””””…..C. 50 years ago, a Meteorologist had the bright idea of using the output temperature of an optical pyrometer with an IR filter to give the S-B IR Irradiance. Pyrgeometers are calibrated against a cavity black body’s Irradiance, not a real energy flux. Their output signal is Irradiance……”””””
Well AlecM, you clearly are NOT reading, what I am EXCEPTING from YOUR POST.
My gripe is with your INCORRECT use of the term IRRADIANCE as a physical property of a RADIATION SOURCE. It is NOT a property of any gizmo. It is a measure of RADIATION ENERGY impinging on ANY surface; particularly a Radiation DETECTOR.
So now you decide to compound the felony, with this gobbledegook:-
“””””…..When incident on a plane pyrgeometer detector, the instrument outputs an approximation to Irradiance of the atmosphere but in reality it is the instrument’s internal black body Radiant Emittance minus the Radiant Emittance of the detector surface to the lower emissivity and perhaps slightly cooler atmosphere. In other words, the instrument transfers energy to the atmosphere and the convolved signal is far from the real atmospheric Radiant Emittance..
For starters, only the ATMOSPHERE can observe the IRRADIANCE of the atmosphere; unless you have some wonderful detector, that occupies no space, and is totally transparent to ALL EM RADIATION.
Any real detector, occupies space, and in order to measure IRRADIANCE it must absorb the radiation that falls on its sensitive surface.
The atmosphere is irradiated over 4 pi steradians, receiving radiation from all directions. Any detector can only receive some portions of that flux.
So now you have SOURCES measured by IRRADIANCE, plus you have DETECTORS characterized by an EMITTANCE. So now you have both of them exactly backwards.
Perhaps you could write say just ONE paragraph on just exactly what the CONVOLVED SIGNAL is. That’s new material you have sprung on us.
Have you ever considered writing an entry for the annual Bulwer Lytton Prize competition.
That’s a polite title for the Bu**S*** prize. You could win it.
They don’t fail ludicrously. There are significant uncertainties for reasons I have described but then there is also a concerted effort, driven by ideology (and, in some cases, also economic interests) to discredit them through half-truths and falsehoods, driven by the same factors that attack all science that is inconvenient to certain political, ideological, or religious views. Attacks on science by ideologues like yourself are nothing new…and all of them have very similar modis operandi (which is why, for example, the primary group defending evolution science has added the defense of climate science to its agenda).
And we have a one-paragraph winna, folks, in Logical Fallacy Bingo:
http://lifesnow.com/bingo/
Love the way ya tied in religious extremism to the “concerted effort” to discredit taking the MME Mean of 36 different but closely related climate models in CMIP5, ignoring entirely the number of PPE runs contributing to the means of each being used, not considering whether or not some of the CMIP5 models might have failed an elementary hypothesis test when compared to the past and present data outside of the reference/training set, not considering the fact that the entire stack of e.g. GISS models are all closely related and hence that the statistical size of the “ensemble” (it isn’t) is much smaller than one might expect if one assumes the usual statistics of random iid samples drawn from a distribution, and then use the flat unweighted mean of this to assign “high confidence” to model derived predictions used to (try to) control the public expenditure of a few trillion dollars a decade for the next six or seven decades. Appeal to motive, appeal to consequence, appeal to ridicule, straw man, appeal to hypocrisy, appeal to spite, factually inaccurate (I, at least, am an atheist, politically disengaged, ideology free, unpaid by oil interests, etc), argumentum ad populum, appeal to fear, — Bingo!
C’mon, you can do better than that. Whether or not the models are failing “ludicrously” is, agreed, a matter of what one wants to call a hypothesis-test p-value that I eyeball out at strictly less than 0.01 for most, but possibly not all, of the models contributing to CMIP5’s MME. Whether or not one uses emotionally weighted terminology at all, it is very difficult to argue that the models collectively or singly are proving to be particularly accurate as predictors of the climate over most of the future and the past of the reference period. See figure 9.8a in AR5 and see what you think.
rgb
@george e smith: Wow, what a response. I won’t give a long reply. Pyrgeometers do not measure a real energy flux, just Irradiance, a potential energy flux. The Trenberth et al Energy Budget is plain wrong; you can’t have a Perpetual Motion Machine. Sorry to have caused you pain.
rgbatduke says:
May 22, 2014 at 2:02 pm
I have been impressed by your observation that one, two or a few models have not failed ludicrously, & you’re right. But the vast majority, IMO, warrant that characterization of their obvious, glaring lack of skill.
Maybe we could learn from something the few at most did to get results closer to reality, as adjusted.
I’d like to amend my prior statement that climate modeling isn’t science. It would have been more accurate (or precise) to say that climate modeling can be a useful tool if the limitations are understood, assumptions are justified by observations (most surely not the case with GCMs, as for instance re. water vapor feedbacks) & are properly improved when shown to have failed, rather than changing the data or selecting new start dates for more predictions, as in “climate science” modeling.
The abject failure of GCMs is why I’m supporting Congressman David McKinley’s amendment to cut funding for the worst waste, abuse & fraud in climate “science”. The tens to hundreds of billions thrown away so far are only the tip of the iceberg, since the results of climate “science” to date have led to policies wasting on the order of a trillion dollars & costing lives.
Contrary to Joel’s accusation, I’m defending science, not attacking it by getting on this political band wagon. I favor spending public funds on real science, not dangerous junk designed to increase the power of bureaucrats & promote the careers of phony “scientists” who so disdain the scientific method.
PS: I quantified “ludicrous” as outside the models’ error bars”, but IMO the Latinate adjective also applies to starting over with new predictions using the same models (akin to Einstein’s definition of insanity) & to the laughably unscientific practice of adjusting data instead of the models’ parameters. The Latin origin of its etymology (probably from the word for a stage play) also puts me in mind of “travesty”, ie, dressed to deceive, cognate with “transvestite”.
AlecM — Your whole argument boils down to this:
You prefer to calculate the heat transfer with an equation in the form of
d = a * (b – c)
(The instruments you deal with effectively use this form as well.)
A lot of other people prefer to use an equation in the form of
d = (a * b) – (a * c)
You claim they are completely wrong to do so!
To put particular values on this (using numbers you have used – the exact numbers are not important), a lot of people say that the earth’s surface is radiating 396 W/m^2 up (a * b) and the atmosphere is radiating 333 W/m^2 down (a * c). You say, “No, no, no! That’s all wrong! It’s just 63 W/m^2 up [a * (b – c)]!”
At best, you have a semantic quibble. The end result of the two calculations is the same – don’t you remember the distributive property that we all learned when we were 8 or 9 years old in math class?
But the bigger point is that the second form represents the underlying physical reality better. In radiative heat exchange between two bodies, there really are two opposing radiation “flows”, each carrying energy. We understand these down to the photon level, with e = h * v. Radiation absorbed by either body adds to the internal energy of that body (even if it originates from a body of lower temperature); radiation emitted by either body subtracts from the internal energy of that body.
In this exchange, ALWAYS more radiative power from the higher-temperature body is absorbed by the lower-temperature body than radiative power from the lower-temperature body is absorbed by the higher-temperature body. So there is no 2nd Law violation in this radiative exchange. The NET transfer is always from hotter to colder.
For purposes of calculating the net heat transfer, it is a nice analytical abstraction to treat the two temperatures as relative potentials (as with voltages in an electric circuit or pressures in a fluid system), then treat the resulting heat transfer as a single unidirectional flow, like a fluid. I use this abstraction all the time. But it is an abstraction – I have not ever found a single reference to a “heaton” carrying this one-directional flow. Or did you study this stuff so long ago that the caloric theory was still in vogue?
Kristian: You say, “It is the TEMPERATURE (and specifically the temperature PROFILE, the gradient away from the solar-heated surface) of the atmosphere that makes it an insulating layer for the surface.”
For an atmosphere that is transparent to radiation, what is it insulating the surface from? The vacuum of space?
Take any cubic foot of the atmosphere. The energy is flying around in every single direction, bouncing around in thousands of different directions within that cubic foot. Some of the energy is traveling by way of em radiation photons, some through molecular collisional exchange.
Trillions of photons are traversing that cubic foot every millisecond and trillions of molecular collisions are occurring every millisecond.
Back-radiation is what any gas in a cubic foot will do. Back- radiation is what any liquid will do and what any solid will do, including a glacial ice sheet.
The solar energy is mostly moving down to the Earth’s surface in that square foot of air (even in cloud). The balancing outgoing radiation is mostly going up and out to space.
There is lag between the solar radiation coming in and the outgoing radiation going out. It is migrating its way through trillions of molecules first. The average delay is about 44 hours. How come “time” is not a component of the equations.
Time delay and the randomness of radiation flow within a cubic foot of air is a better description of the real universe than backradiation.
Bill Illis says:
May 22, 2014 at 6:05 pm
FWIW, I find this description of reality compelling.
Curt: Just wanted to commend you on your very nice and concise summary (http://wattsupwiththat.com/2014/05/21/is-the-climate-computable/#comment-1643722) of what is wrong with AlecM’s confused rantings in this thread.
joeldshore says:
May 22, 2014 at 8:14 pm
Look forward to your clarification on confused rantings on this thread. Especially do I anticipate your presentation of actual scientific evidence in support of the hypothesis that carbon dioxide is the primary driver of climate change. I know for a fact that it is the primary driver of grant money for climate “science”.
Thanks.
To paraphrase the first movie I remember seeing:
“Come back, Shore! Come back!”
milodonharlani;
Especially do I anticipate your presentation of actual scientific evidence in support of the hypothesis that carbon dioxide is the primary driver of climate change.
>>>>>>>>>>>>>>>>>>
Two separate issues. While we may disagree with Joel in regards to CO2’s effects, AlecM’s claims are preposterous as both RGB and JD and others have already pointed out. Curt is entirely correct. We should not tolerate AlecM’s complete tripe if we want the science world and the public at large to take skeptics seriously. If someone claims that 2+2=5, I really don’t care if they are a skeptic or a warmist, they are just wrong.
“Or did you study this stuff so long ago that the caloric theory was still in vogue?”
Well, maybe he learned it from the ‘science’ experts. The ‘science’ still uses the caloric theory. It’s full of ‘heat trapped’, ‘heat stored’… http://en.wikipedia.org/wiki/Caloric_theory
Bill Illis says, May 22, 2014 at 6:05 pm:
“There is lag between the solar radiation coming in and the outgoing radiation going out. It is migrating its way through trillions of molecules first. The average delay is about 44 hours. How come “time” is not a component of the equations.
Time delay and the randomness of radiation flow within a cubic foot of air is a better description of the real universe than backradiation.”
You’re on to something, Bill. The point is, though, that the delay in outgoing as compared to incoming (solar) – at a certain surface temperature – is because of the slowness of moving air against gravity, not ‘moving’ radiation. Convection is what brings the surface energy up to a level where it CAN be radiated back to space. Energy to space is going out as radiation from whatever level convection brings it. Earth’s own thermal radiation is temperature governed, not temperature governing. It’s called ‘thermal radiation’ because it’s caused by temperature, not because it causes temperature.
The atmosphere sure does act as an insulating layer around the earth. No doubt. But this insulating effect stems from two things, the same two mechanisms that ALL normal insulation work by: 1) it sets a limit to the energy escape rate from the surface – at a certain temperature – by the fact that it is able to warm (the surface warms it and thereby sets up a less than max temp gradient away from itself, unlike space, which ISN’T able to warm), and 2) it sets a limit to the energy escape rate from the surface – at a certain temperature – by countering its direct and coupled buoyant/evaporative response to solar heating, meaning these rates become finite (‘sub-max’) for a specific temperature and a specific atmospheric weight (downward force) on the surface. The atmosphere simply exerts a pressure on the surface above 0. Space doesn’t. The heavier the atmosphere, the higher the pressure, the higher the steady-state surface temperature.
At some point, atmospheric science and meteorology turned into a ‘radiation physics’ playground. Now the meme has become: ‘If you understand atmospheric radiation, then you understand why the atmosphere warms the surface.’ Robert Brown promotes this idea just upthread by trying to ‘push’ Getty’s radiation textbook on us ignorants. ‘Solve the differential equations and you will see the light!’ That’s the problem, if you’ve got the base premise wrong, maths won’t help you. It will just reinforce your flawed preconceptions.
@davidmhoffer: ‘2+2=5’!
Readers, the above post completely misrepresents the situation. The Trenberth-Kiehl energy budget, which appears to be the basis of the radiant energy heat generation term in the IPCC climate models, creates energy by using an incorrect radiative heat transfer concept.
This is to confuse individual Irradiances, from and to the surface of the Earth, with real net IR energy transfer, the vector sum of those irradiances. There is no way out of this. The K-T assumption gives 3+(-2) = 5; standard physics gives the correct 3 + (-2) =1. The former is a Perpetual Motion Machine of the 2nd Kind. The latter can be proved by simple wave theory.
As time goes on and there continues to be no Global Warming from the extra ~16% CO2 so far from 1997, there can be no ‘missing heat’ into the oceans: it never existed in the first place. It also appears to be the case that the non-feedback CO2 climate sensitivity is lower than 1.2 K.
I have asked the protagonists above, and I do so again, is there a physics or engineering reference which proves, by calorimetry, that the opposing Irradiance terms at a plane between two IR emitters in radiative equilibrium are separate energy streams? The ‘Two-stream approximation’, which gets the correct result in programmes like, e.g. MODTRAN works because the opposing ‘streams’ add as vectors. You have to do the same at the interface between matter and the atmosphere.
The K-T Energy Budget does not do this, which is why it goes wrong. It appears to be because someone in the dim distant past confused Irradiance for a real energy flow and concluded the IR term in the energy flow from the surface to the atmosphere had to be set to this, an assumption which cannot be justified in practice. As the IPCC climate modelling appears to be based on this misconception, it is no wonder that the predictions are diverging from reality. There is no way out and sooner or later this nettle has to be grasped.
PS I have had to accept many insults from the protagonists of this incorrect physics. However, it is my duty as a scientist sworn to objectivity and honesty to continue to press the point. I could still be wrong but the greater the ad hominem slurs and blustering, with no scientific backuo, the more I’m convinced I’m right!
george e. smith says, May 22, 2014 at 1:36 pm:
The point is this, George: Pyrgeometers do not detect ‘impinging radiation’ from the atmosphere unless the atmosphere happens to be WARMER than their sensor. Pyrgeometers detect the heat flux TO or FROM their sensor. Pyrgeometer warmer than the atmosphere, the heat flux is negative. The ‘downward component’ of any radiative exchange is then CALCULATED using a specified black body formula based on 1) the detected outgoing heat flux, and 2) the absolute temperature of the sensor. This is no secret.
In spectrometers/interferometers the sensors are COOLED to extremely low temperatures. OF COURSE they would detect impinging radiation from the atmosphere. The atmosphere is warmer than the sensor. Heat (also ‘radiative heat’) moves from warmer to cooler. This is not ‘back radiation’. The sensor does not heat the atmosphere. This is ‘forward radiation’. Heat.
It is physically impossible to separately detect either the upward or the downward component of a radiative exchange. It’s in their nature. They are both part of an integrated (indivisible) radiation field between the two objects in question. You can’t pick out one wavefront moving through it and leave the other. Only the (net) FLOW/transfer of energy from the warmer to the cooler object is a physically real working flux. Like an electric current. Like wind. From high to low potential. Always. Individual electrons or air molecules of course fly in all directions all the time. But that doesn’t change the fact that the (bulk) FLOW moves only one way.
I really don’t get why people have such a hard time understanding this.
What’s strange is this: Why do all radiation diagrams pointing down show the radiation coming specifically from the frequency bands of the so-called ‘GHGs’, while radiation diagrams pointing up show the opposite, the radiation coming specifically NOT from the so-called ‘GHG’ frequency bands? Wouldn’t it still be the ‘GHGs’ actually emitting the radiation to space? Absorbing AND emitting IR?
Look, the ‘GHGs’ clearly absorb IR radiation in their respective spectral bands, they do not necessarily reemit it in the same bands. They normally don’t have the time. They collide with other air molecules before they can. Contributing to the atmospheric temperature. The radiation we observe is ‘bulk temperature’ radiation, not ‘spectral reemission’ radiation.
OK this started off on computing and chaos and has deteriorated into the usual idiotic there is no backradiation arguments from slayers. Thread closed, since we all have better things to do thank moderate this dreck.