UPDATE: Jeff provides his answer below
Guest post by Jeff Condon (reposted by request from The Air vent)
Derek has been in a war with ScienceofDoom over the what appears to be Planck radiation. I’m actually not sure of his position because it doesn’t make sense yet to me but he left a thought experiment on the thread which could make for some interesting discussion. Some will find it pretty easy, while I bet others will get all tied in knots over it. As a suggestion, taking a thought experiment to an extreme is often a good way to identify a preferred design path or to understand differences in similar situations. I will give the answers in the coming days, they are already written so I can’t back out but as you consider them I’ll warn that this post is not about the subtleties but rather about the bulk differences.
I’m going to paraphrase Derek’s experiment below and then add another of my own. If it’s not the exact same as his it doesn’t matter the idea is still interesting.
For our experiment assume we have a bolometric camera for measuring emitted thermal radiation as an image. IOW a cool toy which in this case happens to detect all EM wavelengths with perfect sensitivity. To be clear, the camera integrates to measure the radiative emission temperature of the object.
We have two plants, one is contained in a transparent box (greenhouse) the other in open air, both thermally stable (temperature isn’t changing). We take an image of the two plants in the early afternoon on our fancy camera, what do you find in the image?
Derek asserts that the greenhouse plant will be warmer and therefore brighter, but lets continue this experiment further.
For our second experiment we have two thermally stabilized earths, one which has today’s CO2 and one which has 2X today’s level. All other conditions are identical and for some quirk of Id-ian physics, they orbit one right behind the other around the sun such that we can observe them simultaneously on our fancy camera. Now the CO2 of the higher concentration planet will block some of the emitted radiation creating the AGW greenhouse effect so the planet has a 1C warmer surface temperature. (For this thought experiment basic physics are required, planets are stabilized and I’m going with a 1C estimate chosen at random). Since it’s my universe, I’m staying on the warm Earth with a functional economy (right side) and sending all the vegetable eating enviros over to the cold economically devastated one on the left. haha- too fun, I probably should stick to the science for this though.
Now from a distant point we observe our otherwise identical worlds using our amazingly fancy camera. What would our camera reveal?
I’ll give the answers to these with supporting explanations tomorrow or the next day depending on how much fun people are having.
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1/2/2011 Jeff’s answer:
Ok, so the point of this thought experiment was to engage the public in a consideration of the differences between the greenhouse effect and an actual greenhouse. Most here already know that the name itself is a misnomer, but by considering the physics of what is going on we can better understand the argument and better present our opinions on the subject. The majority of the answer below was emailed to Anthony yesterday before he ran the post at WUWT with the note- just to make sure I can’t back out!
I know everyone is wondering what my answers will be to the two greenhouse situations, we’ll see how many will be convinced to change their opinions – or insist that I change mine 😉 . It turns out that both problems are fairly straightforward when considered from an engineering standpoint. In the thermally stabilized systems of the example where temperature is not changing, energy into the system is equal to energy out. We’ll cover the greenhouse vs free air plant situation first. Both plants receive the same energy but the ability to remove heat from the system is limited in the greenhouse plant through convection and evaporation. So in the case of the free air plant, although it is receiving the same energy it has 3 methods of cooling: convection, evaporation and radiation. In the case of the greenhouse, we can consider evaporation and convection negligible so the only option to release the energy is through radiation. Since our camera is only measuring radiation, and since both plants must emit the same energy they receive, the free air plant radiation will sum like this:
Measured EM radiation = Energy in – convection energy – evaporation energy
the greenhouse will sum like this
Measured EM radiation = Energy in – zero convection energy – zero evaporation energy
Therefore the camera will show the greenhouse plant as warmer (brighter) than the free air plant. This holds true even if we include non-zero convection and evaporation for the greenhouse because they are still reduced values requiring a higher EM emission to balance the energy equations.
So now we have the situation where we have two planets, one with more CO2 than the other. We know that CO2 absorbs certain outgoing wavelengths of light. We also know energy in is equal to energy out for both planets. Although this is called the greenhouse effect, it is actually quite different. For both the high and low CO2 planets, the only available cooling mechanism is EM radiation. All the energy coming in has to escape by EM radiation to space, so the equations balance like this.
Measured EM radiation = Energy in
That’s it really. Both planets will measure exactly the same to our camera yet one has a higher surface temperature. The reason this works is that the average energy emission altitude has gone up, allowing a warmer surface yet the net flow is the same.
Caveats: Now I warned that some will get tied in knots over the nuance of this example. There are all kinds of subtleties of the situation which cause minute differences in the planet example. For instance, increasing CO2 will increase the albedo to incoming light, reducing reflected energy and we get a microscopically higher energy in and therefore were our camera of perfect accuracy we could measure a very slightly higher measured radiation from the warmer planet. If this is your explanation, we are in agreement. There are other details as well, but in bulk the answers are A – greenhouse plant is brighter, and B – both are the same.
I read several comments which got the right answer, Carrick was the first to write the correct answer in the comments at tAV, although he kept the answers subtle enough that people had to read it carefully. If you were one who got them both, congratulations. If you are unconvinced by my explanations, ask away and I’ll do my best.
Jeff
By definition anything that is warmer will transmit more EM energy. A greenhouse causes the inside to be warmer so it will transmit more EM energy.
A planet that is 1C warmer (regardless of the cause) will transmit more energy. If the planet loses more energy than it receives, the excess energy loss will result in cooling until the equilibrium is reached.
Therefore the warmer planet will show as warmer until such a time that it is not warmer. Since the Earth does not instantly reach equilibrium it can lose more energy than it receives for a while, then it will cool down and likely then receive more energy than it gains until it warms up.
Any system with a lag will have such overshoot unless the PID’s are finely tuned.
John Kehr
The Inconvenient Skeptic
Burned by the lack of preview…
Since the Earth does not instantly reach equilibrium it can lose more energy than it receives for a while, then it will cool down and likely then receive more energy than it loses until it warms up.
For a tongue in cheek explanation in plain English, both the physics and the economics are explained (in complete agreement with Jeff) here. I am not responsible for coffee, beer, or anything else that gets sprayed on keyboards at the punch line:
http://knowledgedrift.wordpress.com/climate-humour-page-the-climatologist-and-follow-the-money-series/the-physicist-and-the-climatologist-follow-the-money/
On a more serious note, not only is Jeff’s explanation accurate, consider the transition phase from doubling CO2 instantly to a new equilibrium. The physics would suggest the camera would see a ripple, or shimmer, followed by a new steady state identical to before doubling. Jeff and the physics are backed up by the data. See the paper by Beenstock and Reingewertz that looks at the climate data and concludes, yup, that’s what happens:
http://wattsupwiththat.com/2010/02/14/new-paper-on/
jae.
if you’re looking for oracles, seek no further than mr Huffman.
http://stores.lulu.com/hdhsciences
if you want to understand the greenhouse effect on Venus, I’ll suggest other sources
http://www.spacetoday.org/SolSys/Venus/VenusGreenhouse.html
http://www.astronomynotes.com/solarsys/s9.htm
and even carl sagan was wrong above venus. so I guess its ok for you to be wrong as well.
http://www.aip.org/history/climate/Venus.htm
You or anyone else is welcomed to take the facts as we know them about venusian atmopshere and predict what the temperature at the surface will be. If your solution ignores every bit of radiative physics we know to be true AND you get the right answer, that would be something to write home about.
So, Jae, fire up Your physics, and given the constituients of the venusian atmosphere
predict the temperature you would see?
this might help
http://www.imcce.fr/vt2004/en/fiches/fiche_n13_eng.html
Jeff Id says:
January 2, 2011 at 5:18 pm
Will,
“I was not aware that gases formed and presented two dimensional heat emitting surfaces around objects such as planets.”
You should read up on basic greenhouse theory. The atmosphere has a non zero mean emission altitude, again not controversial physics. Due to the random emission direction, the intensity is uniform as though it were a disk facing you. Look up Lambertian emitter for that. You can however think of it as a shell of slightly larger diameter than the planet.
I well aware of what the basic greenhouse theory states Jeff, thank you. That is why I am here pointing out the fallacies in that theory. Points that many of which you have had to completely ignore in order to continue on with your false assertions.
You say: “The atmosphere has a non zero mean emission altitude, again not controversial physics.”
Meaning that the altitude at which the atmosphere emits radiation is not zero. Well a child could make that point so I guess you are right, well done to you. And yes that surely is not controversial physics is it, right again Jeff!
Actually the atmosphere begins to emit IR to space to any appreciable degree, in the troposphere at cloud level, around 500 meters. Which is why clouds generally begin to form at that hight. That is not controversial physics either. The atmosphere continues to emit IR all the way up to the point at which it no longer exists at all, at between 600 and 1000 kilometres.
So you see the Earths atmosphere is not a Stefan/Boltzmann two dimensional black body Lambertian radiating disk. Not even close.
That is why some of us are saying the “Greenhouse Effect” is not basic physics, it is bogus physics.
So the effective emission altitude is merely an incorrect calculation which falsely depicts the atmosphere as a two dimensional black body disk. But the Earth is neither a Lamertian scatterer nor is it a Lambertian emitter. A Lambertian surface is by definition a two dimensional black body disc. Spheres are not Lambertian surfaces. Particularly spheres that are strongly light from one side by bright stars. And particularly Spheres which posses thick gaseous atmospheres which above a few hundred meters, emit radiation in three dimensions (four if you include time).
You appear to be confusing/mixing emission with albido with regards to Lambertian surfaces. The Atmosphere most certainly does not have a uniform emission intensity. That is why it has a 600 km high bulge on one side the equivalent of 25% of the Earths surface area which tracks the solar point around the Earth and disappears below the Mesosphere at 100 km on the dark side. You know Jeff, its called night and day. Its not controversial physics.
See here: http://www.spinonthat.com/CO2_files/The_Diurnal_Bulge_and_the_Fallacies_of_the_Greenhouse_Effect.html
and here:
http://articles.adsabs.harvard.edu/cgi-bin/nph-iarticle_query?bibcode=1966SAOSR.207…..J&db_key=AST&page_ind=0&plate_select=NO&data_type=GIF&type=SCREEN_GIF&classic=YES
This is why the Earth is not a Stefan/Boltzmann two dimensional black body radiator nor a Lamertian emitting (or scattering) surface.
The so called “Greenhouse Effect” is based on arbitrary calculations, ambiguous assumptions and false science. Is it really any wonder that it can only exist in half baked thought experiments and cannot be physically demonstrated in reality?
Physics that cannot be demonstrated in reality by experiment, is nothing more than statistics.
Statistically speaking, “the tail wags the dog” is a valid statement.
A thought experiment is useful if and only if, it transposes into reality.
Derek’s original experiment is very useful because it clearly can be tested and shown to be correct.
My thought experiment likewise, can be tested in the real world and also shown to be correct. http://wattsupwiththat.com/2011/01/01/greenhouse-thought-experiment/#comment-564125
These thought experiments are useful because they demonstrate physical reality without the need to physically carry out the experiments.
Jeff’s “thought experiment” however can never be show to be correct. Which is why, I suspect, he has tagged it on to Derek’s very valid, legitimate thought experiment.
A thought experiment which can never be tested and verified in reality is utterly useless and can only ever have one purpose. To deceive.
Doubling CO2 does not double the greenhbouse effect. Heinz Hug shows that it
only increases 0.17 %.
Will,
I cannot follow any of what you have written other than you are not happy. Typically, I can follow a science discussion fairly well so hmm…. I’ve also taken a few minutes to check your internet work linked above and can’t follow that either. Weird statements about photons all followed by declarations of certainty that AGW is impossible.
If you have a question, I’m happy to try and answer but this discussion isn’t going anywhere.
Will is correct, IMHO. Heat Storage is the key. Rocks radiate back and forth, too, but we don’t call that a “greenhouse effect.”
It’s interesting watching people DEMAND that they are correct on issues that are as clear as mud!
Jae,
“Will is correct”
You’re kidding right? His posts are unintelligible.
Anthony,
Thanks for the opportunity on this post, I hope that some enjoyed it. It was my hope that people would understand this as the simple experiment it is and perhaps be better able to express the true problems with AGW theory – of which there are many.
Everyone,
The true AGW discussion going on in publication revolves around the magnitude rather than these simple points. Keep in mind that with all that said, the magnitude of warming by CO2 can still be undetectably small and whatever magnitude is very possibly below natural variability. I’ve seen no proof that it isn’t and the more I read the closer my position drifts to Lindzen. In my opinion, it makes for a better discussion when people grasp the basics but as has been clearly pointed out, there will always be those who don’t/won’t get it.
Jeff Id says:
January 3, 2011 at 7:20 am
Will,
I cannot follow any of what you have written other than you are not happy. Typically, I can follow a science discussion fairly well so hmm…. I’ve also taken a few minutes to check your internet work linked above and can’t follow that either. Weird statements about photons all followed by declarations of certainty that AGW is impossible.
If you have a question, I’m happy to try and answer but this discussion isn’t going anywhere.
Jeff,
I have given a clear example of a thought experiment which can be readily reproduced. and proves that the so called “Greenhouse Effect” is a false perpetual motion machine that does not occur in the real world.
Once again here: http://wattsupwiththat.com/2011/01/01/greenhouse-thought-experiment/#comment-564125
Simply, adding more bricks to a night storage heater does not increase the temperature, in fact the overall effect is a reduction in temperature because the energy is more widely transmitted and the “negative feedbacks” dominate. Still you don’t have to take me at my word you can do the experiment in the real world and see for yourself.
My Diurnal Bulge paper has been reviewed by thousands of individuals with scientific backgrounds and some have even stated that it makes more sense to them than anything they have ever read on the subject. It got two wow’s from a member of Mensa, though not being a name dropper I won’t mention it here.
One very well known IPCC reviewer (again no names) called it “another attack on the Steffan/Boltzmann law”, but I corrected him as per my above posts on that subject and he quickly fell silent on the issue.
And finally I have reproducible real world experimental evidence which back up the fact that increasing CO2 does not cause an increases in temperature.
It is no surprise to me that you feel this discussion is going nowhere Jeff!
As far as any questions I may want to ask you Jeff, I can’t think of anything in particular but thanks all the same.
Jeff: I agree with everything in your thought experiments, EXCEPT that I don’t think the temperature goes up significantly. Which you almost said in your last post. The energized CO2 almost instantaneously transfers energy to other air molecules, warming them. They then rise. More CO2/more radiation , more rising molecules. PLUS all of Lindzen’s concepts.
I’ve bucked many a hay bale on the Great Plains (Eastern CO, to be exact), and I’m very familiar with the weather patterns out there. The cool dry artic air plays tag with the humid air from the Gulf all year long, sometimes creating violent storms. But often the humid air just gradually replaces the dry air without even causing clouds. So some clear July days have high humidity and some have low humidity, even when the soil is as dry as toast. But despite the wide variations in humidity on these clear days, temperatures are NOT hotter on the humid days. Water vapor is the strongest greenhouse gas. If the greenhouse effect were all that important, it seems to me that one should see hotter weather on humid days.
“EXCEPT that I don’t think the temperature goes up significantly. Which you almost said in your last post.”
I certainly wouldn’t imply that on purpose. I’ve got no idea if the models are right but from my limited experience in reading the equations and code, they look like magic to me.
wayne says: Mike D. … [your] crude remarks to marginalize many here are not needed from your shallow and incorrect viewpoint.
Whoops. My bad. Sorry, your worship. Far be it for me to disturb majestic thinking.
The “thought experiment” proposed to measure (or sense) the warmth (escaping thermal radiation) of two plants, one in a greenhouse and one “in open air”. The assumption is that both plants are “thermally stable (temperature isn’t changing)”.
Pardon my ignorance, doctor, but if an object is thermically stable, doesn’t that mean it radiates no energy at all? Other than fissioning (matter become energy) atoms, what undisturbed matter radiates energy but doesn’t change temperature?
Of course, I am not a physicist, so I have no clue. I do know that greenhouses trap heat, but that’s just my empirical finding, based on my lying eyes, and not on theoretical physics about which I know less than nothing. My tiny brain can’t grasp the problem.
I see that Mr. Id has now given his answer, “In … thermally stabilized systems … energy into the system is equal to energy out.” Pretty much what I said above. He goes on, “Therefore the camera will show the greenhouse plant as warmer (brighter) than the free air plant.”
Stunning. The plant in the greenhouse will be warmer. Who’d a thunk it? Besides me, I mean, and 29.8% of the poll takers. The other 70.2% think the plant in the greenhouse would be the same temperature or cooler. And I’m the shallow and incorrect one?
Mea culpa. I bow down to the giants of theoretical physics. I’m just a hick from the sticks who happens to own and operate a greenhouse. I think it’s warmer in there, but what do I know?
Will, how is your thought experiment different from the following (which mostly uses your words) …
I have three IDENTICAL HOMES. The FURNACE is the same on each so the amount of energy consumed during the ON period ( from say 12:30 am to 7:30 am) is exactly the same for each FURNACE. The observation period is 24 hours.
A) Is left as is.
B) I have removed all the INSULATION
C) I have added EXTRA INSULATION.
1. Does C) become warmer than A) because of the extra INSULATION?
You seem to answer “no”, but I know *I* would rather live in (C). 24/7 it will be warmer than (A) which will be warmer than (B).
“It got two wow’s from a member of Mensa, though not being a name dropper I won’t mention it here. “
And your point is … ? Mensa members are “from 2 to more than 100 … preschoolers to high school dropouts to people with multiple doctorates … professors and truck drivers, scientists and firefighters, computer programmers and farmers, artists, military people, musicians, laborers, police officers, glassblowers….”
High IQ does not in any way correlate to an understanding of GHGs.
Tim
You have simply exchanged a transmitting substance for a non-transmitting/insulating substance. And then try to imply that it is the same experiment.
Am I not supposed to notice that “clever” slight of hand?
Or are you one of those people who believe CO2 is a heat “trapping gas”?
“High IQ does not in any way correlate to an understanding of GHGs.”
Interestingly enough, believe it or not, neither does a low IQ.
FYO the Mensa guy was a chemical analyst but my only point was simply that Jeff was not very convincing when he claimed that he didn’t understand my posts or that they are quote: “unintelligible”
There are many who would disagree.
As another explanation of the greenhouse effect I’m not sure what this article is supposed to be explaining.
In the first example between the two plants, the measurement of radiation is taken off of the surface of the plants within their respective systems. In the second example, the measurement of radiation is taken off of the surface of the entire system (top of atmosphere) after each has achieved equilibrium. The second example isn’t truly analogous because the measurement isn’t taken off of a plant within the system, but as a distributed average of measurements taken across the entire system’s edge.
Is that what the article is trying to explain – that although any given object may be warmer in the stronger greenhouse, each system as a whole must radiate the same amount of energy that it receives (eventually, at equilibrium)? If we measure less heat coming off of the system than going in, that system is heating up internally – which would be the case as the morning sun first hits the greenhouse. If we measure more heat radiating out than going in, the system is cooling down – a greenhouse just after sunset. The system with the higher heat capacity will take longer to swing back and forth from equilibrium, but the net flow of energy into/out of each system will eventually balance to zero, and since the flow of energy into both systems are equal, the flows out must eventually become equal.
Of course no physics are violated. I just don’t understand exactly how and why. I’m aware of the fact that you don’t want to get too much into detail, but if we don’t think it through to the end it’s not a thought experiment but rather an illustration of a preconceived concept. And we have too much of this already. Maybe someone else can help?
Following the arguments brought up by Michael Hammer above, Jeff’s (and my) statement that the image of the 2x CO2 planet is “larger and dimmer” (however slightly) is not correct. The outmost layers of the atmosphere, the stratosphere and above, are not affected by a doubling of CO2, therefore the size of the image of our “warmer” planet would not be different from the “cooler” planet. (The proposed higher emission altitude due to doubling of CO2 would just affect the brightness in that part of the image, not the overall size.)
I would restate: The images of both planets have the same size and overall brightness, but the distribution of thermal radiation might be slightly different.
The surface of the 2xCO2 planet will be a little brighter (because Jeff said so, basic physics) therefore some part of the atmosphere must appear cooler.
But how exactly does the troposphere or the tropopause get cooler when the surface warms up? That’s what I still don’t understand.
I understand the tropopause is emitting energy in the CO2 absorption bandwidth because there is not much CO2 in the tropopause to block it. The tropopause of our 2xCO2 planet gets the same energy form above (the sun and the stratosphere) and a little less energy from below in the CO2 absorption bandwidth. But isn’t this counteracted by more radiation at all other frequencies? Therefore I would say the tropopause on either planet is emitting the same amount of energy but maybe at slightly different frequencies. (Our camera won’t notice.)
In the troposphere we have most of the CO2 effect. As far as I understand it, it is like this: CO2, like any other gas, is absorbing all kinds of frequencies from above and below and is emitting the same amount of energy at slightly different frequencies because it is not emitting in its absorption bandwidth. We said before: if the surface is warmer now, some part of the atmosphere must be cooler. And CO2 is responsible. Is CO2 cooling the troposphere?
Most likely some of my reasoning is totally wrong, because if not, CO2 would help to transform the “dangerous” long wave radiation form the surface to less dangerous frequencies and may be even cooling parts of the atmosphere. What am I missing?
I am sure all the politicians understand how the climate works by now. Could somebody please help an economist understand it – in the end, it will land on our desks.
Thank you all.
Jeff Id says on January 3, 2011 at 9:04 am:
“The true AGW discussion going on in publication revolves around the magnitude rather than these simple points. Keep in mind that with all that said, the magnitude of warming by CO2 can still be undetectably small and whatever magnitude is very possibly below natural variability. I’ve seen no proof that it isn’t and the more I read the closer my position drifts to Lindzen. In my opinion, it makes for a better discussion when people grasp the basics but as has been clearly pointed out, there will always be those who don’t/won’t get it.”
I must confess Jeff that I am one of those dumb-sculls who don’t get it. That is not exactly the same as, in the same breath, to say that I won’t get it. I shall of course get it (I hope) when a few things as to where my thinking is going wrong is explained to me.
Hope You can do that, please read my thoughts below first:
One of the main reasons why I cannot grasp the “Greenhouse Theory” is this: I see Radiation, Conduction and Convection/ Evaporation as “Energy Transportation Systems” (ETS). It is therefore implausible, to my mind, that any of the above ETSs can increase the global temperature any more than the passenger railway system can increase the world’s human population – Nor any more than you can increase the temperature of water in a glass by pouring it into another glass and back again -.
I have seen and read many so called explanations for the “Greenhouse Theory” and as Dr. Roy Spencer is one man who knows a thing or two about what is happening I thought he might have a good explanation, but no, though he has had many attempts.
In his blog under the title Global Warming 101 he writes:
“As we add more CO2, more infrared energy is trapped, strengthing the Earth’s greenhouse effect. This causes a warming tendency in the lower atmosphere and at the surface. As of 2008, it is believed that we have enhanced the Earth’s natural greenhouse effect by about 1%.”
He has no plausible explanation for this enhancement, but adds: “Global warming theory says that the lower atmosphere must then respond to this energy imbalance (less IR radiation being lost than solar energy being absorbed) by causing an increase in temperature (which causes an increase in the IR escaping to space) until the emitted IR radiation once again equals the amount of absorbed sunlight. That is, the Earth must increase its temperature until global energy balance is once again restored. This is the basic explanation of global warming theory.”
Ok, so now I know the basic explanation of global warming theory. Fine but I want to know how the lower atmosphere can perform this trick of responding to this energy imbalance by causing an increase in temperature (which causes an increase in the IR escaping to space) until the emitted IR radiation once again equals the amount of absorbed sunlight. That is, how does the Earth increase its temperature until global energy balance is once again restored?
And then Dr Spencer adds an explanation: “(The same energy balance concept applies to a pot of water on a stove set on “low”. The water warms until the rate of energy loss through evaporation, convective air currents, and infrared radiation equals the rate of energy gain from the stove, at which point the water remains at a constant temperature. If you turn the heat up a tiny bit more, the temperature of the water will rise again until the extra amount of energy lost by the pot once again equals the energy gained from the stove, at which point a new, warmer equilibrium temperature is reached.)”
So then according to Dr. Spencer the answer is simple; “The concept is, just turn the heat up a tiny bit more”
He probably instinctively knows that back radiation from the rising steam or from the pot itself in general is not enough.
He could instead have increased the pots temperature by putting a lid on it or swapped the pot for a pressure cooker and thus stopped convection. But that would only have proved my point that when compared to convection, radiation (which every fan of the “Greenhouse Theory” is quoting as being “the master”at every opportunity) happens to be just a minor player.
Having said all that Dr. Roy Spencer is still a hero of mine and he has a good article on his blog today. You should all read it!
I have no idea what the point was, but maybe the hidden question was: Why is this irrelevant to AGW? Answer, because total emitted radiation is trivially equal to total absorbed radiation, and has little to do with conditions on the planet.
Dude, you are boring.
OH:
“But that would only have proved my point that when compared to convection, radiation (which every fan of the “Greenhouse Theory” is quoting as being “the master”at every opportunity) happens to be just a minor player.”
On behalf of us heretical skeptics, I think you are correct. These radiation freaks can see nothing else! It’s like a video game to them, perhaps?
Will,
I misunderstood the term “electric night storage heater” — I had never run across that phrase before and was thinking simply “electric heater”. After googling it, I have a better understanding of your example.
But even now I still don’t think it is a particularly apt analogy. You seem to be considering the atmosphere as the “thermal bricks” when in fact the heat capacity of the atmosphere is relatively small compared to the land and the oceans. The earth would be the thermal bricks and the atmosphere would be more analogous to the container around the bricks.
The storage heater gains energy from the electric heater; much like the earth gains energy from the sun. The storage heater loses energy as well, by convection, conduction and radiation to the cooler surrounding room (~20 C) thru the container. The earth similarly loses energy by radiation to the cooler outer space (~2.7K) thru the atmosphere. (There is no convection or conduction to outer space)
It seems the analogy you have is “there are three storage heaters, one that is inside a poorly insulated container, one that is inside a well insulated container, and one that is inside no container.” Then, yes, the well insulated storage heater will get warmer than the other, and will stay warmer longer.
Going farther, since the earth does not cool off to the temperature of its surroundings at night (ie 2.7 K of space), we should postulate that the storage heater also does not cool off to the temperature of its surroundings (ie 20 C in the house). So a the end of the first day of use, heater A might be still 22 C inside. Heater B might have cooled to 20.5 C. Heater C might be 25 C. When you then turn on the storage heaters the second night, they will reach a higher temp than the first night, and at the end of the day, they might be 20.6 C, 23 C, and 27 C. Eventually the increased heat loss from the hotter storage heaters will limit the temperatures, but indeed the temperatures will be different at maximum and on average.
“That which absorbs, equally emits, AKA Kirchhoffs Law. “
Yes, indeed. Specifically, the emissivity applies equally to absorption of photons and emission of photons. But this refers to efficiency, not amount.
If a given volume of atmosphere absorbs 10% of the 1.2 um photons coming into it (ie 10% as many photons as a perfect blackbody would absorb), it will also emit 10% as many 1.2 um photons as a perfect blackbody would. But since a chunk of the atmosphere is cooler than the surface, it will be absorbing 10% of a large number of photons (from the warmer surface) and will be emitting 10% of a smaller number of photons (from the cooler atmosphere). There will therefore be a net transfer of energy from ground to the atmosphere = warming of the atmosphere from IR radiation.
“CO2 does not heat the atmosphere any more than water vapour does.”
Quite true. H20 is much more prevalent and hence is a more effective greenhouse gas and hence heats the atmosphere more via IR radiation than CO2 does. But both do indeed heat the atmosphere.