Guest Post by Ira Glickstein
Solar “light” radiation in = Earth “heat” radiation to Space out! That’s old news to those of us who understand all energy is fungible (may be converted to different forms of energy) and energy/mass is conserved (cannot be created nor destroyed).
My Visualizing series [Physical Analogy, Atmospheric Windows, Emission Spectra, and Molecules/Photons] has garnered almost 2000 comments, mostly positive. I’ve learned a lot from WUWT readers who know more than I do. However, some commenters seem to have been taken in by scientific-sounding objections to the basic science behind the Atmospheric “Greenhouse Effect”. Their objections seemed to add more heat than light to the discussion. This posting is designed to get back to basics and perhaps transform our heated arguments into more enlightened understanding :^)
As I’ve mentioned before, during my long career as a system engineer I’ve worked with many talented mathematical analysts who always provided precise results, mostly correct, but some precisely wrong, usually due to mistaken assumptions. I got into the habit of doing a “back of the envelope” calculation of my own as a “sanity check” on their results. If their results matched within reasonable limits, I accepted them. If not, I investigated further. In those days my analysis was really done using a slide rule and scrap paper, but I now use spreadsheets.
The graphic above is based on an excellent spreadsheet from http://serc.carleton.edu/files/introgeo/models/mathematical/examples/XLPlanck.xls. It uses Planck’s Law to calculate the black body radiation spectrum from the Sun, as observed at the top of the Earth’s Atmosphere. It also may be used to calculate the radiation spectrum from the Earth System (Atmosphere and Surface, see below for explanation) at any assumed temperature. (I will refer to this spreadsheet as “Carleton” in this posting.)
I modified the Carleton spreadsheet to compute the mean Solar radiation per square meter absorbed by the Earth System, which turns out to be 240 Watts/m^2. I then used the spreadsheet to determine the effective mean temperature of the Earth System that would emit an equal amount of energy to Space, and that turned out to be 255 Kelvins (-18ºC which is 1ºF).
Since the mean temperature at the surface of the Earth is 288 Kelvins (+15ºC which is 59ºF), that leaves 33 Kelvins (33ºC which is 58ºF) to be accounted for. Guess how we acount for it?
The yellow curve (above left) shows that Solar radiation is in a tall, narrow “shortwave” range, from about 0.1μm (microns, or millionths of a meter) to about 4μm, which we call ultra-violet, visual, and near-infrared. The vertical axis is Intensity of the radiation, measured in Watts/m^2/μm, and the horizontal axis is Wavelength, measured in μm. If you divide the area under the yellow curve into vertical strips, and add up the total area, you get 240 Watts/m^2.
Since we humans sense the visual portion of this radiation as “light”, that is the name we give it, and that has led to the false assumption that it contains no “heat” (or “thermal”) energy.
The violet curve (above right) shows that, assuming a mean temperature of 255 K, Earth System radiation to Space is in a squat, wide “longwave” range, from about 5μm to beyond 40μm, which we call mid- and far-infrared. If you divide the area under the violet curve into vertical strips, and add up the total area, you get the same 240 Watts/m^2 as is under the yellow curve.
DETAILED EXPLANATION
The graph on the left shows the actual observed Solar radiation spectrum (in red) as measured at the top of the Atmosphere. It is superimposed on a black body model (in blue) showing very good correlation. Thus, while the Sun is not exactly a black body, it is OK to assume it is for this type of “sanity check” exercise.
If you calculate the area under the curve you get about 1366 Watts/m^2. That means that a square meter of perfect black body material, held perpendicular to the Sun, would absorb 1366 Watts.
However, the Earth is not a perfect black body, neither is it a flat surface perpendicular to the Sun! So, to plot the yellow curve at the top of this posting, I had to adjust that value accordingly. There are two adjustments:
- The Earth may be approximated as a sphere, with the Sun shining on only half of it at any given time. The adjustment factor for this correction is 0.25.
- The albedo (reflectiveness) of the Earth system, primarily clouds and light-colored areas on the Surface such as ice, causes some of the Solar radiation to be reflected back out to Space without contributing any energy to the Earth System. The adjustment factor for this correction is 0.7.
After applying these adjustments, the net Solar energy absorbed by the Earth System is 240 Watts/m^2.
The graph on the right shows the black body model for an Earth System at a mean temperature of 255 K, a temperature that results in the same 240 Watts/m^2 being emitted out to Space.
Of course, the Earth System is not a perfect black body, as shown by the graph in the upper panel of the illustration below, which plots actual observations from 20 km looking down. (Adapted from Grant Petty, A First Course in Atmospheric Radiation, Figure 8.2, http://www.sundogpublishing.com/AtmosRad/Excerpts/index.html.)
The actual measured radiation is the dark squiggly curve. Note that it jigs and jags up and down between the topmost dashed curve, which is the black body spectrum for a temperature of 270 K and a lower dashed curve which is the black body spectrum for 230 K. This data was taken over the Arctic, most likely during the daytime. The Petty book also has a graph looking down from over the Tropical Pacific which ranges from 300 K down to 210 K. Observations will vary by tens of degrees from day to night, summer to winter, and Tropical to Polar.
However, it is clear that my result, based on matching 240 Watts/m^2, is within a reasonable range of the true mean temperature of the Earth System as viewed from Space.
NOTE ABOUT THE ABOVE ILLUSTRATION
WUWT readers will notice some apparent inconsistencies in the graphs above. The top and bottom panels, from Petty, peak at 15μm to 20μm, while the purple, blue, and black curves in the middle panel, and the Earth System curves from the Carleton spreadsheet I used (see above) peak in the 9μm to 11μm range. Also, the Petty black body curves peak at a “Radiance” around 100 mW/m^2/sr cm^-1 while the black body curves from Carleton peak at an “Intensity” of around 14 W/m^2/μm. Furthermore, if you look closely at the Petty curves, the labels on the black body curves are mirror image! What is going on?
Well, I know some of the reasons, but not all. (I hope commenters who are more fluent in this than I am will confirm my explanations and provide more information about the differences between “Radiance” and “Intensity”.) I have Googled and Wikied the Internet and am still somewhat confused. Here is what I know:
- The horizontal axis in Petty’s plots are what he calls “Wavenumber”, increasing from left to right, which is the number of waves that fit into a cm (centimeter, one hundredth of a meter).
- This is proportional to the frequency of the radiation, and the frequency is the inverse of the wavelength. Thus, his plots are the mirror image of plots based on wavelength increasing from left to right.
- The spreadsheet I used, and my previous experience with visual, and near-, mid-, and far-IR as used in military systems, always uses wavelength increasing from left to right.
- So, when I constructed the above illustration, I reversed Petty’s curves, which explains why the labels on the black body curves are mirror image.
- Fortunately, Petty also included a wavelength legend, which I faithfully reproduced, in non-mirror image, at the top of each plot.
But, that still does not explain why the Petty black body curves peak at a longer wavelength than the Carleton spreadsheet and other graphics on the Internet. I tried to reproduce Petty’s blackbody curves by multiplying the Carleton values by the wavelength (μm) and that did not move the peak to the right enough. So, I multiplied by the wavelength again (μm^2) and, voila, the peaks agreed! (I hope some WUWT reader will explain why the Petty graphs have this perverse effect. advTHANKSance!)
ANSWERING THE OBJECTIONS TO BASIC ATMOSPHERIC “GREENHOUSE EFFECT” SCIENCE
First of all, let me be clear where I am coming from. I’m a Lukewarmer-Skeptic who accepts that H2O, CO2 and other so-called “greenhouse gases” in the Atmosphere do cause the mean temperature of the Earth Surface and Atmosphere to be higher than they would be if everything was the same (Solar radiation, Earth System Albedo, …) but the Atmosphere was pure nitrogen. The main scientific question for me, is how much does the increase in human-caused CO2 and human-caused albedo reduction increase the mean temperature above what it would be with natural cycles and processes? My answer is “not much”, because perhaps 0.1ºC to 0.2ºC of the supposed 0.8ºC increase since 1880 is due to human activities. The rest is due to natural cycles and processes over which we humans have no control. The main public policy question for me, is how much should we (society) do about it? Again, my answer is “not much”, because the effect is small and a limited increase in temperatures and CO2 may turn out to have a net benefit.
So, my motivation for this Visualizing series is not to add to the Alarmist “the sky is falling” panic, but rather to help my fellow Skeptics avoid the natural temptation to fall into an “equal and opposite” falsehood, which some of those on my side, who I call “Disbelievers”, do when they fail to acknowledge the basic facts of the role of H2O and CO2 and other gases in helping to keep temperatures in a livable range.
Objection #1: Visual and near-visual radiation is merely “light” which lacks the “quality” or “oomph” to impart warmth to objects upon which it happens to fall.
Answer #1: A NASA webpage targeted at children is sometimes cited because they say the near-IR beam from a TV remote control is not warm to the touch. Of course, that is not because it is near-visual radiation, but rather because it is very low power. All energy is fungible, and can be changed from one form to another. Thus, the 240 Watts/m^2 of visible and near-visible Solar energy that reaches and is absorbed by the Earth System, has the effect of warming the Earth System exactly as much as an equal number of Watts/m^2 of “thermal” mid- and far-IR radiation.
Objection #2: The Atmosphere, which is cooler than the Earth Surface, cannot warm the Earth Surface.
Answer #2: The Second law of Thermodynamics is often cited as the source of this falsehood. The correct interpretation is that the Second Law refers to net warming, which can only pass from the warmer to the cooler object. The back-radiation from the Atmosphere to the Earth Surface has been measured (see lower panel in the above illustration). All matter above absolute zero emits radiation and, once emitted, that radiation does not know if it is travelling from a warmer to a cooler surface or vice-versa. Once it arrives it will either be reflected or absorbed, according to its wavelength and the characteristics of the material it happens to impact.
Objection #3: The Atmospheric “Greenhouse Effect” is fictional. A glass greenhouse works mainly by preventing or reducing convection and the Atmosphere does not work that way at all.
Answer #3: I always try to put “scare quotes” around the word “greenhouse” unless referring to the glass variety because the term is misleading. Yes, a glass greenhouse works by restricting convection, and the fact that glass passes shortwave radiation and not longwave makes only a minor contribution. Thus, I agree it is unfortunate that the established term for the Atmospheric warming effect is a bit of a misnomer. However, we are stuck with it. But, enough of semantics. Notice that the Earth System mean temperature I had to use to provide 240 Watts/m^2 of radiation to Space to balance the input absorbed from by the Earth System from the Sun was 255 K. However, the actual mean temperature at the Surface is closer to 288 K. How to explain the extra 33 K (33ºC or 58ºF)? The only rational explanation is the back-radiation from the Atmosphere to the Surface.
PS Just saw your latest posts. I guess I was looking for the baby elephant !!!!
Thanks Wayne for your thoughtful comments. Trust, but verify.
I agree that some of the downwellng radiation comes from very low reaches of the Atmosphere, but why does that make a difference in this discussion? Does it matter to the argument that hundreds of Watts/m^2 pass from the Atmosphere to the Surface due to the ill-named “greenhouse effect”?
Would the argument be stronger if most of the radiation came from 100 meters up in the Atmosphere, or 1000 meters, or higher? Where would we have to draw the line such that the 66 Watts/m^2 net exchange from Surface to Atmosphere that we all agree upon would apply?
It seems to me it is natural to draw the line just above the Surface, because that is where liquid sea and solid land change to gas (air). When does an airplane become airborne? When it leaves the runway. Certainly not when it passes 100 meters or 1000 meters!
So, if we draw the line just above the Surface, we get around 324 coming down and 390 going up, with a difference of 66. If we draw it at 1 km we get some lower number coming down and also a lower number going up, with a slightly smaller difference. OK, let us raise that line higher and higher. We get successively smaller numbers going up and going down and the 66 Watts/m^2 also decreases. No matter how high we raise the dividing line, we will still get some amount coming down.
So what is the point? Our Warmist opponents take the fact that radiation comes down from somewhere in the Atmosphere due to certain gases, including CO2. So, they say, more CO2 and other so-called “greenhouse gases” will warm the Surface further and all the ice will melt and oceans will rise and we are all doomed. They spin that clearly established fact to unreasonable extremes so they can impose Cap and Trade and the EPA ruling that CO2 is a toxin and all their agenda to regulate industry and commerce and control the world. So, let us admit the fact that there is and always will be downwelling radiation from the Atmosphere (no matter how high you draw the dividing line) and then correctly argue that there is absolutely no “tipping point” or Catastrophic AGW and, furthermore, a moderate increase in CO2 and temperature is most likely of net benefit to civilization.
You cannot get rid of downwelling radiation from the Atmosphere to the Surface completely unless you draw the line very near the TOA, and I do not think that is what you are suggesting.
Dave Springer – I’d love it if your hunch, apparently backed up by the published paper you cite, is correct and explains why CO2 sensitivity is much lower than the official climate Team contends. Put me in for 0.2ºC to 0.4ºC sensitivity for CO2 doubling (in contrast to the IPCC 2ºC to 4.5ºC).
Why don’t you write up a new WUWT posting, at the appropriate scientific level for our audience, and offer it to Anthony as a Guest Contributor posting?
Or, if you’d rather, write it up in WUWT style and email it to me ira@techie.com and, if I agree with the argument and so on, I’ll help with the formatting and post it (if Anthony and you agree) under my Guest Contributor authorship with you credited as Co-Author. I think this could be a major contribution to the Skeptic cause, if, of course, it holds up as a major contributor to the enhanced temperatures we living things enjoy in Earth.
David Springer,
I seems the paper you reference deals with tropical oceans. It is not surprising that they absorb more then they emit, since warm ocean currents carry large amounts of energy from the tropics toward the poles. That might affect your conclusions a bit.
I’m not convinced overall that your analysis is correct, but I don’t have time right now to dig deeper into it. At first glance, it would seem that the most your “ocean greenhouse effect” could do would be to warm lower layers of the ocean warmer than they would be without such an effect.
Dave Springer says:
By the way, note that it says NET emission of longwave radiation. Compare this to the Trenberth and Kiehl estimate for the whole globe that you have 396 W/m^2 going up from the surface and 333 W/m^2 coming down from the atmosphere, for a net of 63 W/m^2 upward. So, the two numbers (one a global estimate and one just an estimate over the oceans) are in reasonably good agreement considering that they don’t measure exactly the same thing.
Can you be a little clearer on what part is “fatal for the GHG hypothesis” and why?
Joel Shore says:
May 15, 2011 at 8:05 am
First of all, an issue of terminology that has sometimes tripped me up too ..:”Heat” is the name given to the net energy flow, so it is not technically correct to talk about “heat from colder to hotter”.
Nope. Heat is energy on the move from one location to another on a molecular level as a result of temperature difference. It always flows spontaneously from the hotter to the colder.
Rather, it is most correct to say that the heat, i.e. net flow of energy, is always from hotter to colder but that there are energy exchanges going both ways, with the energy flow from hotter to colder always being larger than that from colder to hotter.
You can say that is correct, but as it doesn’t make sense in the physical world where heat always flows spontaneously from hotter to colder I have no reason to take your saying so seriously.
At any rate, I have question for you Myrrh: In your view, when exactly did these incorrect concepts take over physics? I have the textbook here that I used as an undergraduate. It is “Introduction to Statistical Mechanics and Thermodynamics” by Keith Stowe, copyright 1984.
I don’t know. But obviously before that book was published..
Here is some of what it says about the Second Law:
Prove it. Claiming it doesn’t, when it is quite clear in Science that the law refers to heat energy in transit on a molecular level, which can be by conduction, convection or radiation, is contradicting the law; the onus is on you to prove your change of it.
Yeah, and pigs might fly.
Probability which excludes taking into consideration the physical nature of the properties and their real interactions, is Alice through the looking glass. Heat does not flow spontaneously from colder to hotter, it violates reality. Science is the study of reality, not fantasy. Water does not flow uphill spontaneously. It takes Work to alter that reality. Work is also energy in transit, as Heat is.
Clearly, we can base our studies on a law whose chance of violation is so miniscule and we can rest assured that we will never witness a violation. In fact, every moment of our existence we bet our very own lives on these odds, and needless to say, we always win.
Irrelevant.
Prove that heat flows from a colder to a hotter spontaneously or you are violating the 2nd Law which says it doesn’t.
Write your own laws for your fantasy world if you must, but quit mangling those articulating our natural reality, and certainly quit claiming that your rewording isn’t novel because as you’ve given the quote it clearly denies the 2nd Law, and as it is novel, it requires to be proved.
So, perhaps it’s you who should find out how come you were taught this violation of the Law where you’ve not only extrapolated probability by including the oh so miniscule impossible, water does not flow uphill spontaneously, but have turned over all your reasoning to saying the impossible is our actual reality.
It seems clear to me that the “jury is still out” regarding even the most basic, simple part of the CAGW junkscience: the GHE theory. I keep changing my mind about what is relevant and what is not, and I still don’t have a definite position about what is factual, after years of reading this stuff. I find that fascinating. I’m not a physicist, but I have a PhD in carbohydrate chemistry; so I think I can easily understand the basic science, here. Whatever your position, you gotta admit that it is strange that we have so little (in fact, none) empirical evidence on something that appears to be so basic and important. Everyone think s(he)’s right, but nobody can really demonstrate it to the satisfaction of everyone. Weird.
The real marvel that separates planet earth from all others (that we know of (and probably all we will ever know of)) is HOH. Most of the mystery of all that is being discussed here can probably be attributed to this “weird” substance that behaves so differently from nearly all known substances.
I doubt that this means much for anyone here, but I find it fascinating, none the less.
Wayne in answer to your question re my equation for absorption of LWIR – below is part of spreadsheet (out of alignment slightly) showing band energy absorbed after 10, 1000, 2000m etc as emissivity and absorptivity progressively change.
Emissivity and absorptivity
Gray body
L metres 10 1000 2000 3600
Nominal gas temp deg C ‘C4’ 20 20 20 20
Emissive power entire spectrum 119.8 119.8 119.8 119.8 Btu/hft^2
Absorption by CO2 of land IR L m 4.9 20.1 23.6 24.4 Btu/hft^2
Total absorbable energy in bands 24.4 24.4 24.4 24.4 Btu/hft^2
Energy absorbed by gas 4.9 20.1 23.6 24.4 Btu/hft^2
Energy remaining after L m 19.5 4.2 0.8 0.0 Btu/hft^2
Typical equation for energy absorbed by gas is:
(1+0.9)/2*o.193*0.1713*10^-8*(20*1.8+492)^4
Wayne, this a similar spreadsheet for water vapour showing a much shorter distance 120m to absorb 64% of the land LWIR
Emissivity and absorptivity
Gray body
L metres 10 100 120 120
Nominal gas temp deg C 20 20 20 20
Emissive power entire spectrum 119.8 119.8 119.8 119.8 Btu/hft^2
Absorption by H2O of land IR L m 39.9 75.9 76.3 76.3 Btu/hft^2
Total absorbable energy in bands 76.4 76.4 76.4 76.4 Btu/hft^2
Energy absorbed by gas 39.9 75.9 76.3 76.3 Btu/hft^2
Energy remaining after L m 36.5 0.4 0.0 0.0 Btu/hft^2
In this case H2O absorptivity ranges from 0.300 to 0.573
jae says:
As a physicist, it seems clear to me that the “jury is still out” on this to about the same degree as the jury is still out in regards to whether the earth is 6000 years old or 4.6 billion years old. There is absolutely no serious debate in regards to these things in the scientific community; the debate only exists among those who are unwilling to accept scientific evidence that goes against what they desperately want to believe.
I think that what our experience with the whole issue of human origins demonstrates is that whether or not science is doubted by a significant portion of the population, including some trained scientists, depends not on the strength or weakness of the science but instead on whether the science challenges strongly-held religious or ideological beliefs. If it does, then there are people who will argue the science incessantly as a proxy; but their real objections have nothing to do with science.
R Stevenson, thank you very much. This is in a bit of mixed units. No problem at all. However on the final equation I have to guess a bit, I recognize the 0.1713*10^-8*(20*1.8+492)^4 as being the SB in English, Rankine for the temperature, but could you identify the values in the term (1+0.9)/2*o.193 as to what those values are? I don’t immediately recognize what the 0.9 and 0.193 are, or the relationship, but overall that seems to give the total absorbable energy in all bands.
jae, contraire! It matters hugely to some here. I am just realizing that as I extend that new relationship to Venus. The surface is dry, not wet, so when you go to integrate the flux on Venus from the BOA to the TOA you notice the huge difference between Earth and Venus. On Earth you have 168 reaching the surface (KT97 numbers, I think everyone here has them memorized, so without words) of which 78 is immediately subtracted to get the upward flux without the evapo-transpiration influence of water on Earth. Venus has no such subtraction term from the BOA flux upward, it does have dry thermals upward, and to a greater amount partially also because of the lack of water on Venus since the temperature is kept elevated, but still small compared to what evaporation of water would do if it were present. If Venus still had water the temperature would be hugely less at the surface, even less than 370 K, not 740 K. That’s my take so far.
Tim Folkerts says:
May 12, 2011 at 12:32 pm
Mkelly,
The above from an astute person shows clearly that if two objects of the same temperature are radiating at each other there is no (none, nada, zippo) energy exchange HEAT (ie no NET energy exchange). You even say specifically that they are radiating at each other; since radiation = traveling EM energy, you just admitted that energy is being exchanged in the very sentence where you say there is no energy exchange.
q is zero so no energy is exchanged.
mkelly says:
This is wrong…but no matter.
At least, we both agree there would be no heat flow from the earth to the atmosphere if the two are at the same temperature. I think we also both agree that there is heat flow between the sun and the earth. Given such a state of affairs, i.e., the earth absorbing heat from the sun and no heat leaving it (in the hypothetical case of an atmosphere at the same temperature as the earth), what would happen: Would the earth remain at the same temperature or would its temperature increase?
Joel Shore said on Visualizing the “Greenhouse Effect” – Light and Heat
May 14, 2011 at 6:55 pm
Why? How does the Second Law work in your picture of the world? Is there a little “Maxwell’s Demon” that stops a photon and asks where it came from and where is it’s going and says, “I am sorry, sir, but you can’t travel in this direction”? Do objects refuse to radiate if toward any hotter objects that they see or do the hotter objects just refuse to accept photons from objects that are colder?
Alleyne replies:
Nope, no little demons. I rather considered the energy radiated from a colder object to act very much like a neutrino, but to pass through matter without affecting it, unlike a neutrino which only very rarely affects it.
Joel Shore said on Visualizing the “Greenhouse Effect” – Light and Heat
May 14, 2011 at 6:55 pm
Why do you believe your conception of the Second Law is correct and the conception of physicists, who actually work intimately with it and understand its derivation from statistical physics principles, is wrong?
Alleyne replies:
The books I have read were written by physicists and chemists who were well versed in, and worked with, these principles. Admittedly most of what have learned was a long time ago and didn’t include statistical thermodynamics. As I have said before, I am merely asking questions and making arguments which I hope will help elucidate your argument and from which I may learn something. I don’t know who you are, or what your qualifications are. The books I have read and the education I have had all taught me that energy flows from regions of high energy to regions of low energy and that heat doesn’t flow from cold to hot, and heat being the transfer of energy ergo energy doesn’t flow from cold to hot. You are telling me something different. You recently chastised someone for believing what Hertzberg and others of his ilk said on the internet, surely you don’t expect me to accept everything I am told over the internet without question? Or is it just because you are saying it that makes it OK 🙂 Not trying to be offensive, just suggesting that you not take these questions so personally. Not everyone on this site is a physicist or a climate scientist. There are people like myself that have an interest in the subject and wish to learn more. If you are indeed a physicist who actually works intimately with and understands these things – wonderful, I may then learn something… And I can appreciate your frustration, if you are one, however I consider the tone of your comments uncalled for at times. There are undoubtedly people who come to this site with as much intelligence, expertise and learning in their field of endeavour as you have in yours. The sarcasm, while you may consider it merited at times, does nothing to elevate the level of the discussion. If I am misinterpreting your comments, easily done over the internet where tone of voice and affect are not evident, I apologize.
Joel Shore said on Visualizing the “Greenhouse Effect” – Light and Heat
May 14, 2011 at 6:55 pm
Yeah…Well, that’s pretty clever but also impossible to implement. How do you direct the energy radiated from the cold sink back to the hot source without having the hot source radiate energy to the cold sink? That’s the whole point: Such a scenario is impossible. The Laws of Radiative Transfer, coupled with Kirchkoff’s Laws regarding emissivity and absorptivity guarantee that this can’t happen.
Alleyne replies:
Well that is substantially a thought experiment from classical thermodynamics, modified to return the energy radiatively to the hot source instead of in the unspecified fashion of the original. Would Kirchoff apply in this case? As we drew off energy and performed work with it the system would no longer be in radiative equilibrium and I thought Kirchoff only applied in that case, or is this another misconception on my part? A lot of the thought experiments in classical thermodynamics are impossible to implement, perfect gases, perfect insulators etc… however the conclusions reached through them are valid and the basis for your statistical thermodynamics. I am not trying to invent a perpetual motion machine, that is part of what I have been objecting to with respect to energy flowing from a cold source to a hot source.
Joel Shore said on Visualizing the “Greenhouse Effect” – Light and Heat
May 14, 2011 at 6:55 pm
I think I see where you might be getting confused: You seem to think that I am just saying as long as some overarching process has flow from hot to cold, we can have different separable sub-processes that have flows in the other direction.
I am not saying that…
Alleyne replies:
I understand what you are saying now, thank you. I need to think on it and do some reading on statistical thermodynamics. Please don’t throw up your hands in disgust 🙂 but I just wonder, if it is a question of photons (as you say) travelling from a cold object to a hot object, and these photons are, on average, lower energy than the average energy of the matter they are travelling toward, wouldn’t it require, in order to transfer all the energy emitted from the cold source to the hot source, that they impinge upon only the lower energy molecules in the hot object? Seems statistically unlikely. I am not arguing against what you say, just trying to understand the mechanism… I have always known an object cools more slowly and reaches a higher equilibrium temperature in a warm surroundings than a cold one, but had considered that an effect of gradient, not as you say a result of energy input from the colder surroundings.
Joel Shore said on Visualizing the “Greenhouse Effect” – Light and Heat
May 14, 2011 at 6:55 pm
Why would you jump to the conclusion that the physics textbooks are wrong on a very fundamental and basic matter of physics and that the scientific consensus is wrong in using equations that have been tested by scientists and engineers and used to build all sorts of technology rather than acknowledge that your own knowledge may be what is limited here?
Alleyne replies:
Because there have been some very bad textbooks and textbooks have been wrong before on basic and fundamental matters. However I really don’t wish to get OT and discuss that here, so let us agree that intelligent, questioning, skepticism is scientific. I do, and have, acknowledged that my knowledge is limited in this area, I never claimed otherwise. I’m not sure I would use the term ‘scientific concensus’ though. Scientific concensus has a bad track record, apart from which I always understood that science wasn’t concensus based but founded on empirical data and repeatable experiments. However this too is OT and more a question of ideology than science, so let us leave it for another time.
Joel Shore said on Visualizing the “Greenhouse Effect” – Light and Heat
May 14, 2011 at 6:55 pm
Yes…You are misunderstanding. You have put in a negative sign so that you end up subtracting numbers that you should be adding. You correctly calculate changes in entropy and then, instead of adding them together to get the total change, you subtract one from the other.
Alleyne replies:
Oooops, my apologies, you are entirely correct, I was apparently too tired to think straight after a long day in the field. For some reason, though I did say you have to sum them, I subtracted them – my bad.
Thanks for taking the time to answer my questions.
Joel Shore says:
May 8, 2011 at 12:06 pm
You [Martin Mason] clearly do not know the basis for the Second Law, which is statistical physics. You seem to believe in some sort of magical version of the Second Law. The actual Second Law is based on the fact that although energy transfers occur in both directions, by simple statistics it becomes essentially astronomically improbable that the net flow of energy, what we call “heat”[,] will be from the hotter body to the colder body for any macroscopic bodies.
———
I don’t think it improbable that the net flow of energy will be from the hotter body to the colder body. I think Martin doubts it improbable too.
I am going to take the moment to claim a “Get Out of the Warmist’s Jail Free” card for myself and Martin. Even those who claim statistical thermodynamic and physics superiority make such asinine statements themselves. I didn’t even have to twist your words. Joel, being intelligent I realize you surely did not mean that (but give us the cards anyway) ☺ and lash yourself to that high-horse next time.
Joel Shore said:
Given such a state of affairs, i.e., the earth absorbing heat from the sun and no heat leaving it (in the hypothetical case of an atmosphere at the same temperature as the earth)**, what would happen: Would the earth remain at the same temperature or would its temperature increase?
**Heat would still leave the atmosphere for outer space, I would have thought even though there is hypothetically no interchange between atmosphere and earth.
Joel Shore
jae says:
It seems clear to me that the “jury is still out” regarding even the most basic, simple part of the CAGW junkscience: the GHE theory.
Joel Shore says
There is absolutely no serious debate in regards to these things in the scientific community.
I say
The science community have NEVER spent any time discussing the “greenhouse theory”.
A tiny clique called the “team” numbering no more than a dozen people in climate science developed this threadbare “theory”.
From this remote and uninteresting branch of science what started out initially as an innocent “spicing up” their papers to get funding has ballooned into a monster.
The average person in the world will see their living standards reduced to pay for the dislocation of the world economy.
Do you think that say Martin Rees Astronomer Royal ever sat down to seriously study the pros and cons of the greenhouse theory?
Or any other notable scientist who was not directly linked to the IPCC bandwagon?
The position of most scientists not in the field would be to assume good faith in those who were.
The climategate tapes indicated that there was something rotten in this branch of science.
It was a wake up call for all in a position to have a critical look at the area.
The hallmarks of the “team” set them apart from the rest of the real science community.
1. Withholding data.
2. Interfering with peer review process
3. Lobbying the media to exclude critical opposition
4. Crude cut and paste graphs (Mann)
Back to the present situation
Joel you know perfectly well that there is no substantial direct heating of the atmosphere by greenhouse gases.
Your simple radiating shells model has gone the way of the plum pudding model of the atom.
Interesting, but of historical interest only.
Some versions of the greenhouse theory are so modest that its a wonder anyone bothered to write them down.
You have witnessed in the last few years several fundamental problems being acknowledged by the IPCC greenhouse theory proponents.
What of the future?
I suspect that even more inconsistencies will be acknowledged .
I would like to see a review of the IPCC conclusions carried out by a dozen or so scientists and statisticians in good standing.
This group should be well qualified but not presently working in the area of climate science.
Effectively it would be a quality audit of the practices of climate science in the previous 20 years or so.
@joel Shore
re; how is this fatal to GHG hypothesis
It wouldn’t matter if downwelling IR was 100% of upwelling IR from the ocean as all the additional downwelling IR does is proportionally increase the evaporation rate in the first micrometer of ocean surface.
Greenhouse warming isn’t thottled by IR absortive gases in the atmosphere over the ocean. It’s throttled by humidity. Over land is a different story but given 71% of the earth’s surface is water that is the lion’s share of the effect. Greenhouse effect is throttled by humidity which determines the rate at which shortwave radiation absorbed by water can escape. Conversely if downwelling IR decreases the evaporation rate decreases and the heat exchange at the ocean/atmosphere boundary remains the same. This is a natural consequence of water being transparent to shortwave and opaque to longwave. Water cannot be heated by longwave IR. All longwave IR does is vaporize liquid water at the surface.
I believe I happened to stumble onto the same hypothesis put forward by Dr. Ferenc Miskolci “The Saturated Greenhouse Effect”
http://www.scribd.com/doc/25071132/The-Saturated-Greenhouse-Effect-Theory-of-Ferenc-Miskolczi
The saturated greenhouse effect is supported by 50 years of TIGR data i.e. radiosonde soundings of the troposphere which reveal that as CO2 level rises water vapor content of the atmosphere falls and thus the total GHG content of the atmosphere remains constant. Miskolczi goes beyond my analysis by looking at what happens to the water vapor after it leaves the ocean surface. It is of course carried upward by convection where it condenses (releasing latent heat far above the surface) and falls back as rain. In a nutshell Miskolczi discovered through analysis of radiosonde sounding data that increased CO2 causes the speed of the water cycle to increase propotionately with the net result being a slightly dryer atmosphere and no change in total greenhouse warming.
This is same claim that I made i.e. that on a water world the ocean is responsible for greenhouse warming and amount of downwelling radiation from GHGs is inconsequential due to the consequences of liquid water being a greenhouse fluid and unlike the atmosphere there is, for all practical purposes, an infinite reservior of greenhouse fluid in the global ocean. In other words if non-condensing atmospheric greenhouse gas content changes the ocean reacts by changing condensing GHG in the opposite direction maintaining a constant maximal greenhouse effect.
Joel:
“There is absolutely no serious debate in regards to these things in the scientific community; the debate only exists among those who are unwilling to accept scientific evidence that goes against what they desperately want to believe.”
More armwaving. Your definition of “serious debate” differs from mine. More “consensus science” crap? No wonder you are so certain about the GHE, too.
Wayne asked
‘could you identify the values in the term (1+0.9)/2*0.193 as to what those values are? I don’t immediately recognize what the 0.9 and 0.193 are, or the relationship, but overall that seems to give the total absorbable energy in all bands.’
0.9 is land emissivity and could be ignored (assume BB) . 0.193 is CO2 absorptivity
at PcL of 4.13406 where Pc is the partial pressure of CO2 (0.00035at) and L is the mean beam length 11812ft (or hemispherical gas mass rad L =3600m) corrected for
temperature PcLTs/Tg.
@joel Shore (con’t)
The red flag went up in my mind when the first paper I cited “Tropical Atlantic Mixed Layer Heat Budget” showed that 25% of insolation energy is removed by LWIR, 5% by conduction, and 70% by latent heat of vaporiation. From other reading, also cited in this thread, only 23% of surface heat loss is assigned to latent heat. If that number is in reality much larger then it drastically changes the surface temperature response because latent heat by definition doesn’t register on a thermometer. It is invisibly carried upward by convection until the vapor condenses adiabatically. So if the lion’s share of insolation energy is removed by latent heat we won’t see any temperature rise near the surface. It’ll happen far above the surface at the cloud layer where the GHGs below the cloud layer now serve to insulate the surface from downwelling IR from the cloud.
You see, you can’t have your cake and eat it too. If GHGs act as insulation between surface and space due to LWIR opacity they must also act as insulation from space to surface for any downwelling LWIR. So if latent heat transport carries a lot of energy aloft, drilling straight through the densest layer of GHG’s like it wasn’t there then when the latent heat becomes sensible again the dense layer of GHGs below it must impede its return to the surface in effect making the easiest radiative path for LWIR emittance by clouds straight up to space.
It was the magnitude of the measured latent heat loss from the ocean in that Atlantic heat budget which inspired me to say it’s fatal to the anthropogenic GHG warming hypothesis because latent heat carries energy away from the surface without sensible warming of near surface air.
Joel Shore says:
May 16, 2011 at 7:53 am
mkelly says:
q is zero so no energy is exchanged.
This is wrong…but no matter.
Sorry Joel, let change q to the more oft used q/A or W/m^2. If one side of the equation is zero then the other is too. So no energy exchange. Watt is joule per second and a joule is a unit of energy I will let my statement stand.
Mr. Springer, although you have disparaged me, I am in general in agreement with you concerning water vapor and the oceans having a large influence on the atmosphere that far exceeds CO2.
@ur momisugly Joel Shore (con’t)
Another way describing the latent heat effect is that increasing CO2 will not change the dry adiabatic lapse rate but it does change the saturated adiabatic lapse rate. Increasing water vapor content decreases the dry adiabatic lapse rate what should be observed with increasing CO2 is a lower lapse rate from surface to cloud layer and increased lapse rate from cloud layer upward. So the net effect is not surface warming but cloud layer warming. I believe this is the notorious “tropical tropospheric hotspot” that GCMs predicted should be found. Where they fail I believe is not at this level but rather in inaccurate modeling of cloud formation and effects on radiation balance i.e. they presume that more clouds cause additional average forcing at the surface and insufficiently account for loss of surface forcing due to high albedo of the cloud tops.
Two presumptions in GCMs that I believe are erroneous are constant average absolute humidity and constant average albedo. Actual instrument measurements of humidity (TIGR) and albedo (Earthshine) indicate they are not the constants they are presumed to be.
R Stevenson, seems I’ve got it all, thanks again.