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)
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Oops … I was typing too fast. That should, of course been …
“Because “back radiation” IS EXACTLY “incoming IR energy ” from the s̶p̶h̶e̶r̶e̶ shell (or the atmosphere for earth)…. “
Bryan says (May 2, 2013 at 4:21 pm): ” My old school textbook A Level Physics by Nelkon & Parker 1973 (pitched about first year American University Standard); also discuss the Greenhouse Effect. But dismiss it as being falsified by R W Wood.”
Could you quote it directly? I found a text-only version of the 3rd Edition (1970) online here
http://archive.org/stream/AdvancedLevelPhysics/NelkonParker-AdvancedLevelPhysics_djvu.txt
It explains that a (real) greenhouse warms by inhibiting convection. It only mentions R W Wood in a discussion about “optical resonance” of mercury vapor.
Gary Hladik says (May 2, 2013 at 5:03 pm): “I found a text-only version of the 3rd Edition (1970) online here…”
And a scanned version here
http://archive.org/details/AdvancedLevelPhysics
It’s not searchable, but it has figures and everything. R W Wood appears on p 359, the real greenhouse on p 360. Two more tidbits:
On p 344 we find the famous Herschel experiment, in which he passed sunlight through a prism and bathed a thermometer in the various resulting colors. Both visible and infrared light raised the thermometer temp, falsifying (again) Myrrh’s bizarre claim that visible light can’t heat a surface. 🙂
A thought experiment on p 356 illustrates “Prevost’s Theory of Exchanges” by moving a warm body C to an enclosure D at lower temperature, or to enclosure F at a higher temperature: “It seems unreasonable to suppose that C stops radiating when it is transferred to F; it is more reasonable to suppose that it goes on radiating but, while it is cooler than F, it absorbs more than it radiates”. There are no computed examples, but it is a pre-2000 reference to so-called “back radiation”. 🙂
Bryan says:
Well, I know google books can be a little finicky about previews, but it works fine for me. Basically, it goes through the simple 1-blackbody shell model illustrating the greenhouse effect and then refers the reader to a source which I think might be the first IPCC report for more details (although the edition year is 1980, it seems that the discussion of the greenhouse effect and Bose Einstein condensation were added in a 1994 reprinting…Let the conspiracy theories begin!!!).
Well, I certainly can imagine it possible that a book of that era could mistakenly say something like that. On the other hand, I found the 1970 edition here http://archive.org/stream/AdvancedLevelPhysics/NelkonParker-AdvancedLevelPhysics#page/n371/mode/2up/search/greenhouse , searched it and all I could find was a single paragraph on greenhouses; it does talk about the fact that greenhouses work by inhibiting convection (p. 360) but it doesn’t say anything about the atmospheric greenhouse effect. Since you often seem to get very confused on basic distinctions like this, perhaps you are misremembering a bit?
That is not really the topic of this current thread. But, just to digress a bit, let’s look at all the previous falsification tests that it has passed since Arrhenius first proposed it a century ago:
(1) Scientists thought the oceans could absorb all the CO2 we emitted and hence that it would not be building up in the atmosphere. It was not until the modern measurements in the lat 1950s, along with the theoretical work of Revelle establishing why the oceans would not absorb it all, that it was understood what actually happens.
(2) Scientists thought that the effect would saturate. It was not until the modern era of radiation transfer theory (and its subsequent verification by the entire field of remote sensing and, in particular, measurements of the radiation seen by satellites from space) that it was understood that such saturation does not occur.
(3) When first proposed, the notion of the water vapor feedback, while plausible, did not have empirical evidence to back it up. Now, there is very good evidence that the feedback operates as predicted ( http://www.sciencemag.org/content/323/5917/1020.summary ) , especially for temperature fluctuations on timescales on the order of months. [It is harder to verify long-term trends in water vapor because of instrumental and satellite changes in radiosondes over time, although the most reliable data do appear to show it, and it is also hard to explain how a feedback operating on the timescales it does could work on the monthly to yearly timescales and fail over the longer timescales.]
Whoops…After submitting, I see that Gary has beaten me to it in finding the 1970 edition of Nelson & Parker.
I also meant to mention at the end of my last post that what I wrote is just a few things I thought of off the top of my head and not meant to be an exhaustive list.
The point is that scientists are testing aspects of AGW every day and the notion that it is not falsifiable is hokem. That said, some people may be disappointed that their grade school notions of falsifiability don’t really apply quite so neatly in the real world, where empirical data and analysis of that data are subject to error to and for nearly all major theories one could dig up data that seems to contradict the theory. It is a constant process of trying to reconcile theory and empirical data / experiment and, once theories are well-established, they are…for good reason…not going to be tossed out every time some piece of empirical data seems to disagree with them.
Gary Hladik says, May 2, 2013 at 12:40 pm:
“Well, let’s be very clear on what I didn’t find. I didn’t find fully-computed textbook examples of problem 1023 aka “steel greenhouse” that supported either “Spencer-type” physics or “Kristian-type” physics. Kristian is of course free to link experiments or computed textbook examples that support his view (good luck).”
Gary, EVERY textbook example supports my position on this. NONE of them supports yours. Why? Because my claim is that is isn’t an issue, because it isn’t an actual physical phenomenon. It isn’t a thing to be discussed. Because it doesn’t happen. It isn’t a thing. Your claim is that it truly and clearly and obviously and naturally is. SO WHY ISN’T IT EVER MENTIONED OR DISCUSSED AT ALL?!!
Gary Hladik says, May 2, 2013 at 12:40 pm:
Gary, kudos for at least trying. Joel and Tim here are doing nothing but frantically waving their hands. No substance or argumentative value whatsoever.
But your thermocouple example just does not cut it. The thermocouple is trying to measure the REAL temperature of the gas. The REAL temperature of the gas is always WARMER than what the thermocouple can measure. The only thing we can do to help the thermocouple is try and make it come closer to the REAL temperature. The heat shield does nothing to heat the thermocouple, Gary. I can see why you would think that. It is the GAS heating it. But it cannot heat it all the way to its REAL temperature because of the simultaneously ongoing radiative heat loss. Reduce the heat loss and the thermocouple comes CLOSER to measure the REAL temperature of the gas. The issue here, though, is: Can the heat shield do anything to help the thermocouple become WARMER than the gas ‘input’?
THAT is what you need to show, Gary. Because THAT is the underlying claim of this whole discussion.
You fail to grasp what my argument is actually about. What it IS saying and what it’s NOT.
Regarding the point I was trying to make in my last post, I want to quote a very relevant and pertinent observation made by commentator CementAFriend on the thread at Tallbloke’s a while back named ‘Entering the SkyDragon’s Lair’.
He said:
“I have not read all the comments but it appears many who are commenting are mentioning supposed models or thought bubbles without having any real experience. The only thing that counts is actual measurement and then relate that to equations, determined from real experience, which could explain the process. This comparison process tells you if your measurements are reasonably accurate or the equations your are attempting to verify are wrong.
I have had experience with measurement in furnaces. My experience is as follows:
a) with a poorly insulated furnace there will be heat loss from the walls which results in a flame temperature less than the theoretical and lower energy in the exhaust gases.
b) as the insulation is improved there is less heat loss from the walls, slightly higher flame temperatures, and higher energy in the exhaust gases
c) even with perfect insulation it is not possible that the flame temperature exceeds that of the theoretical temperature ie energy can not be created to exceed the energy input“
When the theoretical (potential) temperature of an object (like 290K with input of 400 W/m^2 for a blackbody) is attained, no amount of heat shields and insulating layers can raise that temperature further. ONLY THE SOURCE OF HEAT for that particular blackbody could do that.
tjfolkerts says, May 2, 2013 at 12:59 pm:
“Konrad [my name is Kristian] asks: “Can you explain to me the reasoning behind your 1/2, 1/3, 1/4 … succession?”
Clearly I cannot. I have tried once already. Joel has tried. I linked to the wikipedia article for MLI that discusses the problem.”
Wikipedia article for MLI? You specifically stated:
“For blackbody shells
1 layer = 1/2 as much heat loss
2 layers = 1/3 as much heat loss (not 1/4)
3 layers = 1/4 as much heat loss (not 1/8)
…
20 layers = 1/21 as much heat (not 1/ 2^21) So 20 blackbody shells would result in about 5% as much heat loss.”
Let’s take it from the top, Tim. I am not asking you to show me what actually happens in the real world, with real-world logic and equations. I want you to justify the 1/2, 1/3, 1/4 … succession within the framework of your distinctive planet/shell (the Eschenbach setup) logic. You specifically use the halving of the output from the shell’s outer surface to explain the need for the planet to heat up so that the shell output to space grows to equal the input to the planet. Using this logic, if you suddenly were to put TWO shells rather than ONE around the planet, both separated by vacuums, wouldn’t the output to space from the outer shell then (initially, in your case) be one quarter (1/2 * 1/2 – gaining half from the inner shell, splitting it in two and thereby ejecting half of the half from its outer surface) rather than one third of the input to the central planet? And so on …
joeldshore
“although the edition year is 1980, it seems that the discussion of the greenhouse effect and Bose Einstein condensation were added in a 1994 reprinting”
Its a little odd to have have significant additions without a new edition.
My equivalent textbook Heat and Thermodynamics by Zemansky does not mention the Greenhouse Effect
Its difficult to know which Greenhouse Effect you are advocating.
Vaughn Prat (Stanford) claims he has experimental evidence( large temperature differential) of a Greenhouse Effect in a shoebox sized enclosure.
De Witt Payne has spent the best part of two years trying to do the same but with no results.
Both these efforts would attempt to counter R W Wood and the conclusion of Nelkon and Parker that this Greenhouse Effect is really a result of trapped convection.
Vaughn Prats experiment was badly set up and he no longer defends it.
I don’t know of anyone else who believes in a measurable Greenhouse Effect in a shoebox, perhaps you do?
The other more scientifically respectable version requires a troposphere sized column to display the effect .
Testable predictions of this model include
1. Hot Spot
2. Increasing near surface air temperature
3. Increasing height of ERL
4. Decreasing temperature at this height.
None of these things are currently happening, does that not make you think that the CO2 driven AGW theory is false.
If after 30years (say) of negative indicators for your theory would you abandon it?
Joel
G&T cite the Kittel book (2000 print) as only referring to the IPCC report.
Rather than presenting a full exposition of the theory.
Indeed they doubt if such a properly presented rigorous version of this conjecture exists
Read Page 35
Falsification Of the atmospheric CO2 greenhouse effects within the frame Of Physics” by Gerhard Gerlich and Ralf D. Tscheuschner; International Journal of Modern Physics B, Vol. 23, No. 3 (2009)
http://arxiv.org/PS_cache/arxiv/pdf/0707/0707.1161v4.pdf
Gary Hladik says, May 2, 2013 at 1:52 pm:
“Kristian writes: “This is a fundamental mistake you make here… But you see, J1 is not incoming energy. It is part of the outgoing energy flux J from the sphere. All it can do is REDUCE the outgoing. It cannot INCREASE the incoming.”
It just occurred to me that Kristian’s claim is analogous to matter/anti-matter annihilation. You see, half the sphere’s outgoing energy per second (half of 400 watts = 200 watts) is “annihilated” by the “anti-energy” radiated by the inner surface of the shell. The outer shell surface of course radiates “normal” energy at 200 watts, but the inner surface of the same shell radiates “anti-energy”.”
Gee whiz. Trying out the tactic of putting words in my mouth, building a strawman for you to ridicule. Nice.
Gary, the only HEAT input (that is, positive transfer of thermal energy to produce a higher body temperature) to the sphere’s surface is from its internal heat source. This input is equal to J. This the sphere then emits as HEAT loss, to balance this heat GAIN, from its surface into the vacuum surrounding it. Nothing is annihilated.
The point is rather that YOU need half of this outgoing flux to be disallowed from leaving the surface of the sphere in the first place (or ‘annihilated’) to be able to say that the ‘back radiation’ flux (J1) is only reducing the heat LOSS of the sphere’s surface, not increasing its heat GAIN. You see, according to the Stefan-Boltzmann law, the sphere HAS TO emit 400 W/m^2 from its surface at 290K. It gains 400 W/m^2 from its internal heat source, attains a corresponding BB emission temperature of 290K, and emits accordingly. Nothing of this changes with the ‘incoming’ J1. It cannot stop or restrict J from continuously leaving the sphere’s surface.
So if the sphere’s surface temperature rises beyond this equilibrated emission temperature, then it means it has gained HEAT (a positive (net) transfer of thermal energy) from somewhere else, this being the cooler shell. You are transferring HEAT from a cooler to a warmer object. Only problem then is that the HEAT transfer between the sphere and the shell in fact will still always go from sphere to shell, not the other way around. The back radiation from the shell (J1) reduces this heat transfer rate, diminishing the sphere’s ability to heat the shell all the way to 290K (the shell does receive the full 400 W/m^2 after all and absorbs it, but can only reach a steady temperature of 244K). But it does NOT reverse it.
That is what J1 does, it reduces the shell’s temperature by reducing the incoming J -> J – J1. But in no way or fashion is the sphere’s HEAT input (to set its temperature) ever going to be J + J1!
Once again. J is the flux leaving the surface of the sphere. This is intercepted by the shell, heating the shell, but not to 290K, only to 244K. Why? Because the shell splits the 400 W/m^2 of J and turns it into two times J1, one going inwards, one continuing outwards.
So J leaving the sphere in the end becomes (J – J1) + J1 = J. Both the shell AND space are part of the sphere surface’s surroundings. As is its internal heat source. You cannot leave out the flux continuing to space, keeping the flux going back.
I realise this is all Greek to you so that we’ll just keep going around in circles forever. But at this stage I’ve really said all I can say about the matter. There apparently is no way to make you see your total abuse of the laws of thermodynamics here …
This is how energy is conserved in the dual sphere/shell system:
All the energy from the original (internal) power source (400 W/m^2) is turned into heat at the sphere’s surface. This creates a temperature of 290K.
All the energy (400 W/m^2) is then emitted from the sphere’s surface.
All the energy (400 W/m^2) is received and absorbed by the surrounding shell.
HALF of the energy (200 W/m^2) then goes into heating the shell to a temperature of 244K. The other HALF of the energy (200 W/m^2) is emitted from the shell’s outer surface to space.
All the energy is accounted for.
But then you want to suggest that the inward J1 is somehow an additional bunch of energy to all this that cannot leave to space but instead ends up being extra HEAT input to the sphere, warming it some more.
You cannot have both heating of the sphere to only 244K (200 W/m^2 incoming HEAT) and emission of (200+200=) 400 W/m^2 outgoing HEAT as if it had a temperature of 290K. You double count the inward J1.
“HALF of the energy (200 W/m^2) then goes into heating the shell to a temperature of 244K. The other HALF of the energy (200 W/m^2) is emitted from the shell’s outer surface to space.”
Wow! Is the mistake really that simple?
When the system has not yet reached steady-state, then indeed some of the energy goes into heating the shell (and heating the sphere as well). This is not necessary half — if the shell is cold then nearly all the energy goes into heating the shell; if the shell is warm, very little actually goes into raising the temperature of the shell.
But once the object has already reached a steady-state condition where the temperature is not changing, then no more energy goes into “heating it to” that temperature. This a the very familiar equation from high school chemistry (and physics)
Q = mc ΔT
Note specifically the “Δ”, ie the change in temperature. If the shell starts at 244 K and ends at 244 K, then Q = 0 for “holding the shell at 244 K”. There is still the 200 W/m^2 lost to space, so there is still a need for 200 W/m^2 of heating from the planet. So there is still a need for a 200 W/m^2 heater in the planet (but NOT a 400 W/m^2 heater).
Bryan, first of all, I have noticed your failure to even address the issue of whether you can find any support for your claim about what your edition of Nelson & Parker in light of the evidence from the 1970 edition that Gary and I have found. Or, do you now admit that you have completely misrepresented what they wrote?
Bryan says:
I guess you could certainly illustrate some aspects of CO2’s absorption of infrared radiation by such an experiment but to truly replicate the greenhouse effect, you need to have system big enough that there is a significant lapse rate, i.e., convection can never equalize the temperature because of the fact that an adiabatic parcel of air cools as it moves up in the atmosphere and expands.
First of all, the things that you are trying to list all go beyond evidence for the greenhouse effect and address the issue of global warming. Second of all, you have badly garbled them:
1. Even Monckton, the originator of the completely false claim that the “hot spot” is a unique signature of warming due to greenhouse gases now admits (in this very thread) that he was wrong, saying:
(You are also wrong about the extent of empirical evidence for it, but since that is irrelevant, I won’t pursue it further.)
2. Air temperatures have been increasing. Only people who don’t understand statistics are fooled by the claim that is hasn’t warmed for 16 years. (The trend over this carefully cherrypicked period still has large enough error bars that it is statistically-indistinguishable from both no trend and the ongoing trend since ~1975.)
3. I believe there is in fact evidence for the increasing height of the ERL. I certainly know of no evidence that shows that it hasn’t increased.
4. I have no idea what you are talking about on this one. Can you explain to us why a decreasing temperature is predicted at the ERL?
The empirical evidence for the greenhouse effect is actually overwhelming: It is simply impossible to explain how the Earth’s surface can emit 390 W/m^2 but the Earth as seen from space only emits 240 W/m^2 (as required for radiative balance given what it absorbs from the sun) without this difference being due to the absorption by IR-absorbing elements in the atmosphere. The fact that the spectra of the emissions as seen from space corresponds essentially exactly with what is predicted using radiative transfer theory using the known absorption bands of the various IR-absorbing elements is then “icing on the cake”.
Kristian: The error that tjfolkerts has pointed out is exactly what led me to explain how you have what I would call (in analogy with the mechanics case) an Aristotlean view of energy. Aristotle thought that it was necessary to have a net force to keep an object moving at a constant velocity; Newton recognized that you don’t need a net force although in practice (because there is most commonly frictional force slowing things down), you do need a force to balance the friction force so that the net force on the object is zero.
In your view of energy, you think that net energy must be input just to keep an object at a certain temperature. The correct view is that the net energy input to keep the object at a constant temperature is zero. Since the object will be emitting thermal energy, you do need an input to balance that emission. But, that’s not what you are proposing. You are proposing that the energy input to the shell has to exceed the energy that it outputs in order to keep it at a constant temperature.
Or maybe you just haven’t been understanding this whole time that we have been dealing with the steady-state temperature of the objects and not the transients that occur when steady-state has not yet been reached?
Kristian says:
You are dealing with people who know statistical mechanics, the theory that underlies and gives meaning to thermodynamics. This is why we are able to distinguish between what the Second Law of Thermodynamics actually says and your magical view of the 2nd Law (which essentially leads to violations of the First Law because you have energy flows that magically can’t influence the temperature of an object).
I suggest you read this article and try to really digest it, with a little bit of self-reflection: http://en.wikipedia.org/wiki/Dunning%E2%80%93Kruger_effect You won’t, of course, be able to for exactly the reasons that Dunning and Kruger explain.
joeldshore
Can you read?
Look at Nelkon &Parker page 360
The Greenhouse is explained by keeping plants warm through stopping convection.
No mention whatsoever about radiation from the glass having any influence.
These people were quite aware that the the Greenhouse Theory had been falsified by R W Wood.
That then was the consensus view.
Remember in the 1970s climate alarmists like yourself were predicting a new ice age.
Thats why you will find no reference to a greenhouse effect in physics textbooks of the period.
………………………………..
Joel why don’t you present properly the theory you are trying to support?
I said above, highlights and possible testable features include
“2. Increasing near surface air temperature
3. Increasing height of ERL
4. Decreasing temperature at this height.
None of these things are currently happening, does that not make you think that the CO2 driven AGW theory is false.”
You replied
“3. I believe there is in fact evidence for the increasing height of the ERL. I certainly know of no evidence that shows that it hasn’t increased.
4. I have no idea what you are talking about on this one. Can you explain to us why a decreasing temperature is predicted at the ERL?”
Read this link
http://www.realclimate.org/index.php/archives/2004/12/why-does-the-stratosphere-cool-when-the-troposphere-warms/
I notice that you will still be a believer in the Greenhouse Theory even if the near surface temperature declines for the next 30 years.
Well that’s fanaticism for you !
What about 300 years of near surface temperature declines .
Still a faithful believer ?
Bryan says:
Let me quote what you originally claimed:
You have had it explained to you countless times that the “greenhouse effect” is a name given to an effect that is known not to be the same exact mechanism by which a greenhouse works (analogous in some ways but not in others, in particular that one involves radiation and the other convection). Yet you still made a false claim about what your physics textbook said. It is hard to avoid the conclusion that you intentionally misled us with your statement. It is hard to imagine your credibility slipping any lower than it already was, but I am afraid it has.
…Except that more papers in the peer-reviewed literature were predicting warming than cooling and the National Academy of Sciences report from the mid-1970s said that the science was at a state where one could identify the various competing factors influencing the climate but could not yet predict which would win out, which is very different from what they are saying today. So, in fact, what we learn from this is that organizations like the NAS are very cautious and trustworthy.
That doesn’t address the temperature at the ERL, which is well within the troposphere.
Since the greenhouse theory is based on physics which has incredibly strong empirical support, I don’t see what temperature declines would have to do with it. They would certainly have some impact on understanding of what the climate sensitivity is but not on the greenhouse effect itself.
As for whether I would modify my opinions regarding the climate sensitivity if temperatures were to decline for the next 30 years, sure I would if that were actually to come to pass. Why don’t we check back in 30 years and see who had a better understanding of climate and what the future holds in store?
By the way, in regards to what you claimed about Parker and Nelson, it is worse than not distinguishing between the greenhouse effect and the mechanism by which a greenhouse operates. You also invented the fact that they discussed the effect on radiation at all but dismiss it in light of Wood’s experiment. Even in regards to greenhouses only, they did not mention the notion of radiation playing a role and then dismiss it and did not mention Wood at all in this context. Rather, they just talked about how a greenhouse works by limiting convection.
Your whole claim about Parker and Nelson bears essentially no resemblance to reality.
Joel who is this Nelson, you refer to?
I am talking about a book by Nelkon and Parker and gave the page number.
The Greenhouse is not heated by radiation but by suppressed convection.
This observation was made by R W Wood and was the accepted view at that time.
What problem do you have with that?
Sorry for the name typo. The problem that I have with that is that you made the completely false claim “My old school textbook A Level Physics by Nelkon & Parker 1973 (pitched about first year American University Standard); also discuss the Greenhouse Effect. But dismiss it as being falsified by R W Wood.”
Now you have changed that claim to a claim that the authors said something that nobody disputes, despite your attempt to imply otherwise, and which is mentioned in many discussions of the greenhouse effect, including that on Wikipedia.
You basically completely invented what Nelkon and Parker said…and what they actually said had absolutely zero bearing in the atmospheric greenhouse effect.
Joel
I like to look on a positive outcome, yet you say….
“Now you have changed that claim to a claim that the authors said something that nobody disputes”
What about Vaughn Pratt and De Witt Payne?
You now agree with R W Wood , Nelkon and Parker and all others who have studied the topic that radiation has nothing (or very little) to do with the heating effect in a glass house or greenhouse .
Suppressed convection is the cause.
“You basically completely invented what Nelkon and Parker 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
Bryan says:
I don’t see where me or anybody else here has ever disagreed with the statement that in real greenhouses, the primary mechanism for warming is the blocking of convection.
No…You gave us the name of the book and the year. It took research by Gary and I to find that we could actually access it online and when we did, we found that it didn’t say what you claimed it said. So, basically, at the end of the day, your claim that a physics textbook you used “dismissed” the atmospheric greenhouse effect was not true. It simply did not discuss the atmospheric greenhouse effect whatsoever, which is not particularly surprising.
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???
Back to our old friend problem 23, only instead of looking at it as a steel greenhouse, let’s consider it as a temperature measuring device. Our blackbody sphere alone (in a vacuum chamber whose walls are maintained at 0 degrees K) radiates 400 W/m^2. To simplify, let’s make the sphere area 1 square meter, so it’s radiating 400 W (at roughly 290 degress K).
We never specified exactly how the sphere is heated, but note that the solution to problem 1023 doesn’t depend on the method of heating. We only require that the sphere radiate 400 W/m^2, i.e. 400 W. So let’s say it’s hollow, and powered by a miniature nuclear reactor cooled by some circulating gas; the gas is the only thing in contact with the sphere. If the inside sphere wall has some insulation, the gas must necessarily be hotter than the surface of the sphere. Then the outside temperature of the sphere will be an imperfect measure of the inside gas temperature, just as temperature of the unshielded thermocouple in example 9.25 is an imperfect measure of the gas surrounding it. What to do?
Hey, let’s add radiation shields to both sphere and thermocouple. Note that our concentric shield around the sphere is so close to it (though separated by a vacuum) that its inner and outer areas are very close to 1 square meter.
We’ve added a radiation shield to both our measuring devices. Kristian says the thermocouple’s temperature increases with shield present and approaches the surrounding gas temp, making it a more accurate measure of the gas temp. With regard to the sphere (our device for measuring the internal gas temperature), Kristian says that in the presence of its snug radiation shield the sphere’s surface temperature…
A) Increases
B) Decreases
C) Remains the same
making it a…
1) More accurate
2) Les accurate
3) Unchanged
measure of the internal gas temp.
Kristian?
Kristian says:
And, here in your first line is already a major error in your thinking. A certain amount of heat absorbed by the body (in this case from its internal power source) does not create a certain temperature when there are other sources of energy around. That is nonsense that Slayers want you to believe. The temperature of an object is determined by the balance between the total amount of energy it absorbs and energy it emits. If the object starts at a certain temperature at which it is absorbing more energy than it is emitting, this net absorption of energy causes its internal (“thermal”) energy and hence its temperature to increase until it gets to the point where it is emitting as much energy as it is absorbing. If, on the other hand, it starts at a certain temperature at which it is emitting more energy than it is absorbing, this net emission of energy causes its internal (“thermal”) energy and hence its temperature to decrease until it gets to the point where it is absorbing as much energy as it is emitting.
If you don’t understand this first basic concept, there is no reason to proceed any further.
For an object that is surrounded by empty space at absolute zero, its net emissions is equal to its gross emissions and can be calculated from the Stefan-Boltzmann equation P = sigma*T^4. However, for an object surrounded by a shell at a temperature T_0, then the net emission from the surface is
sigma*(T^4-T_0^4).
Those of us not allergic to the concept of back-radiation consider the second term to be the energy emitted from the surroundings absorbed by the object (and, in fact, this is what it is and how it is described in all the textbooks). But, even if you don’t want to think of it this way, the fact is that you will find this equation is nearly every physics textbook that talks about thermal radiation (unless it talks about radiative emission in such a cursory manner that it never discusses net emission given an object’s surroundings).
Note that the temperature T^4 of an object whose emissions are described by the equation above depends not only on whatever power it is absorbing from its internal energy source but also on the temperature of the surroundings T_0.