Guest post by Reed Coray
The following example illustrates the issues I have with reasoning often used to argue that increasing the amount of CO2 in the Earth’s atmosphere will increase both the Earth’s surface temperature and the Earth’s atmosphere temperature. Immediately following is a direct quote from URL
http://www.school-for-champions.com/science/heat_transfer_earth.htm
“The present situation is that there has been an increase in infrared-absorbing gases in the atmosphere, such as carbon dioxide (CO2) and methane (CH4). Energy that would normally escape into space is absorbed by these molecules, thus heating the atmosphere and spreading through convection currents. The average temperature of the atmosphere has increased 0.25 °C since 1980, mainly attributed to an increase in infrared-absorbing gases in the atmosphere.”
Although the above statement makes no direct reference to Earth surface temperature, I believe it carries the implication that greenhouse gases in the Earth’s atmosphere increase the Earth’s surface temperature.
I make two comments: the first is relevant only if the above implication is valid, the second is relevant independent of the validity of the implication. First, placing matter adjacent to a warm surface such that the matter is capable of absorbing/blocking radiation to space from the warm surface can lead to a decrease in the warm surface’s temperature. Second, increasing the amount of the absorbing/blocking matter can lower the temperature of the absorbing/blocking material.
Take for example an internal combustion engine whose metal surface is exposed to a vacuum. In addition to doing useful work, the engine produces thermal energy (heat). That thermal energy will produce a rise in the temperature of the engine’s surface such that in energy-rate equilibrium the rate energy is radiated to space from the engine’s surface is equal to the rate thermal energy is generated within the engine. By attaching radiating plates to the engine’s surface, some of the energy radiated to space from the engine’s original surface will be absorbed/blocked by the plates; but because thermal energy can be transferred from the engine to the plates via both radiation and conduction, the temperature of the engine’s original surface will be lowered. This is the principle of an air-cooled engine[1]: provide a means other than radiation of transferring heat from an engine to a large surface area from which heat can be removed via a combination of conduction, convection and radiation, and the engine’s surface temperature will be lowered.
If plates at a temperature lower than the original engine surface temperature are attached to the engine, it’s true that the temperature of the plates will increase to establish energy-rate equilibrium. Once energy-rate equilibrium is established, however, increasing the plate radiating area (adding additional matter that blocks more of the energy radiated from the original engine surface) will likely lower the plate temperature.
Thus, blocking the amount of surface radiation escaping to space does not necessarily increase the surface temperature; and increasing the amount of radiation blocking material does not necessarily increase the temperature of that material. In both cases (the Earth/Earth-atmosphere and the internal combustion engine in a vacuum), the heat eventually escapes to space–otherwise the temperature of the Earth’s surface and the engine would continue to rise indefinitely. The difference isn’t that the energy doesn’t eventually escape to space (it does in both cases), the difference is in the path the energy takes to reach space. The amount of generated thermal energy in conjunction with the path the thermal energy takes to get to space determines temperatures along the path; and adding more material may increase or decrease those temperatures. To say that “Energy that would normally escape into space is absorbed by these molecules, thus heating the atmosphere…” by itself is unwarranted; because an equivalent statement for the case of adding extra plate material to the engine would be “Energy that would normally escape to space from an engine with small attached plates is absorbed by additional plate material, thus heating the plates…” For air-cooled engines, this statement is not true—otherwise the plate surface area of air-cooled engines would be as small as possible.
It’s fairly easy to visualize why (a) adding thermally radiating plates to an air-cooled engine might decrease the engine’s surface temperature, and (b) increasing the area of the radiating plates might decrease the plate temperature. It’s not so easy to visualize, and may not be true, why (a) adding greenhouse gases to the Earth’s atmosphere decreases the Earth’s surface temperature; and (b) increasing the amount of atmospheric greenhouse gases lowers the temperature of the Earth’s atmosphere. I now present one possible argument. I do not claim that the argument is valid for greenhouse gases in the Earth’s atmosphere, but I do claim that the argument might be valid, and can only be refuted by an analysis more detailed than simply claiming “Energy that would normally escape into space is absorbed by these molecules, thus heating the atmosphere.”
If we assume that (a) matter cannot leave the Earth/Earth-atmosphere system, and (b) non-greenhouse gases radiate negligible energy to space, then for a non-greenhouse gas atmosphere the only way thermal energy can leave the Earth/Earth-atmosphere system to space is via radiation from the surface of the Earth. The rate radiation leaves the surface is in part a function of both the area and temperature of the surface. For a greenhouse gas atmosphere, energy can leave the Earth/Earth-atmosphere system to space both via radiation from the Earth’s surface and radiation from greenhouse gases in the atmosphere. Suppose it is true that the density of greenhouse gases near the Earth’s surface is such that radiation emitted from low-altitude greenhouse gases does not directly escape to space, but is in part directed towards the Earth’s surface and in part absorbed by other atmospheric greenhouse gases. As the atmospheric greenhouse gas density decreases with increasing altitude, radiation emitted from high-altitude greenhouse gases can directly escape to space.
Now it’s not impossible that since (a) in addition to radiation, heat is transferred from the Earth’s surface to greenhouse gases via conduction, and (b) convection currents (i) circulate the heated greenhouse gases to higher altitudes where energy transfer to space can take place and (ii) return cooler greenhouse gases to the Earth’s surface, that the process of heat transfer away from the Earth’s surface via greenhouse gases is more efficient than simple radiation from the Earth’s surface. Many engines are cooled using this concept. Specifically, a coolant is brought into contact with a heated surface which raises the coolant’s temperature via conduction and radiation, and the coolant is moved to a location where thermal energy transfer away from the coolant to a heat sink is more efficient than direct thermal energy transfer from the heated surface to the heat sink.
One way to realize increased thermal transfer efficiency would be to use a coolant, such as greenhouse gases, that efficiently radiates energy in the IR band (i.e., radiates energy at temperatures around 500 K). Another way would be to spread the heated coolant over a large surface area. Since surface area increases with increasing altitude, thereby providing expanded “area” (in the case of a gas, expanded volume) from which radiation to space can occur, it’s not clear to me (one way or the other) that greenhouse gases won’t act as a “coolant” reducing both the temperatures of the Earth’s atmosphere and the Earth surface.
[1] It’s true that for most air-cooled engines the main transfer of heat from the engine plates is via a combination of (a) conduction of heat to the air near the plates, and (b) convection that replaces the warm air near the plates with cooler air. To aid this process, a fan is often employed, or the engine is located on a moving vehicle and the vehicle’s motion through an atmosphere provides the flow of air across the plates. Although conduction/convection may be the primary means of heat dissipation from the plates, radiative cooling also dissipates heat.
Now it’s not impossible that since (a) in addition to radiation, heat is transferred from the Earth’s surface to greenhouse gases via conduction, and (b) convection currents (i) circulate the heated greenhouse gases to higher altitudes where energy transfer to space can take place and (ii) return cooler greenhouse gases to the Earth’s surface, that the process of heat transfer away from the Earth’s surface via greenhouse gases is more efficient than simple radiation from the Earth’s surface.
—————–
It is impossible, assuming I have penetrated the meaning of the obfuscating language.
The green house gases radiating heat into outer space are less efficient at radiating heat than the solid surface is. They do the best job they can but exposing the surface directly to space would be better.
It’s because the heat from the surface has to be transported aloft by convection, the gas cools in the process and so CO2 at -30C and H2O at 0C is radiating heat to space. If there were no atmospheric green house gases the surface at 20C can radiate to space and hotter means more efficient.
Try thinking about adding more matter to your engine in the form of insulation, or just restricting air flow through the engine bay, or adding more matter in the form of rust to your engine cooling system. The engine still has to get rid of the same amount of heat, but the engine core gets hotter.
The surface area argument is also not enough. The atmosphere is a very thin layer relative to the radius of the earth, so the gain in radiating area going from surface to top of atmosphere is minuscule.
For anyone still paying attention at the end of this blog…
The other day I put together a visual of 393 ppm CO2. This number reduces quite nicely to 4 parts per ten thousand. So I bought a plastic bottle with 10,000 bright yellow airsoft BB’s and removed its cardboard central piece to reveal an unobstructed view of all 10,000 BB’s to the viewing world. I then added 4 bright blue airsoft BB’s of the same size.
You can guess the result. Every now and then a single or partial blue will appear or can be identified as one shakes and turns the container. But it is an empty barren field overwhelmed by a sea of yellow. And the blue represents the concentration of a near inert gas. Are highly government grant paid “climate scientists” serious about this? What a joke!! Ask any other scientific discipline, unless their pay is now contingent on the success of the findings after these grants filter through the various “independent” institutions, what their thoughts are on this point.
Think of this as $4 vs $10,000. Or think of it in any equivalent way, the result is the same. How much influence does the expenditure of $4 have on $10,000?
CO2 is rising yes, in 1960 CO2 was somewhere around 300 ppm. I guess that means that in fifty years I can add one additional blue airsoft BB? Maybe it screams to 500 ppm in half that time. Do I add the single additional BB in 25 years? Lets see that would be near 2040, is that a cataclismic date for some? Check the jar. What do you see? Check the non visual models, what are you told.
Konrad says:
July 21, 2012 at 6:11 pm
My very simple question for Joeldshore and Eli Rabett, can non condensing radiative gasses such as CO2 radiate as IR energy they have acquired conductively?
If you mean by conduction, T-V (translational to vibrational) energy transfer, yes.
Greg House says
“Experiments used to verify the equations is public”… What experiments? All the warmists presented was unrelated stuff like “space blanket” or fakes like the recent one from Al Gore.
—————
You simply have not looked far enough. Rather than look on the Internet, which has to much crap and you will not be able to sort out what is crap or not, I suggest you go to a library.
The Al Gore experiment was rubbish. It’s more difficult to do properly than a naive view would expect. But it can be done. Why don’t you do it?
I like the idea of having 7 bottles labeled 1960, 1970, . . . , 2010, and 2020. Then, each should have the appropriate number of blue BBs. This can be used as a visual display of the increasing CO2 problem.
Can you provide a link to the type of container that you purchased?
joeldshore says:
July 21, 2012 at 6:20 pm
==============
I will give you an opportunity to carefully read and edit your comment. Seems to be somewhat of a ramble. Seems to me that you have switched roles and wrote a comment that would be more appropriately directed to the comment you wrote.
dp says:
July 21, 2012 at 5:28 pm
You might get a better example than your engine block for heat transfer problems from this document. It’s a very interesting read.
http://www.projectrho.com/public_html/rocket/supplement/Presby_Engineer_Degree_Thesis.pdf
==============
Interesting. Lotsa deep comprehension required. The heat pipe was the limit for me at one sitting. Very interesting concept there. I’ll add the rest of the paper to my vast wealth of useless knowledge later. It’s that need to know kind of thing!
BTW.
Try it yourselves. Its quite revealing and a lot of fun. Start with a jar of 10,000. (I should have taken four yellows out, but I didn’t – you can). The main point of this exercise is that you will have your atmosphere jar, tuned to CO2 influence.
It is probably pointless to ask you this, but have you never observed, on a moonlit night, the growth of a beautiful cumulus cloud over a distant mountain far away from any possible urban heat island?
I’m not certain why I am still hanging around this thread, but Policy Guy has finally posited an objection that has a certain amount of merit. If you’re prepared to be open minded Policy Guy, I will attempt to explain by extending your analogy.
Imagine for a moment that your jar is the same diameter it is now, but 50,000 feet tall. The blue bb’s are mixed in the exact same ratio as they were before. If I guess that your original jar was say 1 foot tall, that would be 200,000 blue bb’s in the jar. Still only four in ten thousand, but in this use case, scale matters.
What would the cross section be of a single bb? We know that 10,000 fill a 1 foot tall jar, so clearly the cross section of the jar would be something less than 10,000. Let’s take a wild guess and say that it takes 100 bb’s to “cover” the bottom of the jar. Clearly, in a one foot tall jar, four bb’s could don’t even come close to that. But in the 50,000 foot jar, we’ve got 200,000 blue bb’s.
Now imagine a photon going from bottom of the jar to the top in a straight line. The rule that the photon has to follow is that if it hits a yellow bb, it goes straight through. But if it hits a blue bb, it has to stop and take off again in a random direction.
Obviously, in the one foot tall jar, the chance of a photon encountering a blue bb is almost zero. But in the 50,000 foot jar, the possibility that a photon will travel in a straight line without encountering a single blue bb is about zero. The area of “coverage” of 200,000 blue bb’s exceeds the cross sectional area of the bottom of the jar by many, many, many time. By chance, perhaps they are all stacked up in a row on one side? Not likely.
So you can imagine that poor photon trying to escape. Even though Mr Photon only needs to avoid 4 in 10,000 blue bb’s, the chance that there is a straight line through 50,000 feet is pretty much nil. That photon will hit many bb’s and change direction many times before finaly escaping from the top of the jar.
Now double the number of bb’s from 4 per 10,000 to 8 per 10,000. In one foot of jar, that’s almost meaningless. In the 50,000 foot jar, the number of collisions that photon will have with blue bb’s just went way up. There will be many more collisions, and it will take longer for the photon to get out.
Police Guy says:
You might try a similar visual to show how, say, a few parts per million of plutonium in the air would certainly not cause you any harm!
Smokey says:
It is amusing that you think that consensus in science is determined by designing a Soviet-style election whereby only “YES” votes are recorded. And, furthermore, when no attempt is made to determine the qualifications of the signers….Oh wow, they have some sort of degree in “the hard sciences” (rather loosely defined)…Boy is that ever impressive! I love how you guys quibble about the details of how a rigorous poll of scientists is conducted but will then believe something like this that is about as far from scientific as you can possibly get.
That is probably because attempts to circulate such petitions have actually involved the novel idea of only including signers that are clearly qualified to have an informed opinion on the subject…and because organizations representing many, many more than 31000 scientists have made their position on the science crystal clear.
The process of using science to inform public policy actually has defined ways of doing it, of producing consensus documents, that have served our society well. The fact that you even put the OISM petition in the same category is embarrassing.
rgbatduke says:
Indeed.
Yeah…It is a logical fallacy. But, I think it also does illustrate an important point which is that no matter how good the science is on some particular matter, you will have people not believing it simply by virtue of the fact that it goes against what they want to believe. In particular, it illustrates the fallacy in the claim that the various arguments that you see here and at other websites demonstrate that the science of AGW is clearly too unsettled (to take any policy action), or, to put it another way, it demonstrates the dubiousness of claims to the effect that “If scientists could provide sufficiently strong evidence of AGW then I would be convinced. The fact that I am not convinced demonstrates that the science is not sufficiently strong.”
I’ve another simple question for Joel Shore etc : If ”non- radiative” gasses such as N2 and O2, H2 can’t radiate thermal energy in the IR that they have acquired through conduction then a jet of N2 or O2 at 15c emitted by a spacecraft in a vacuum wouldn’t show up on an IR thermal camera would it (but a jet of C02 at 15c would)? The simple experiment’s been done, hasn’t it?
Couldn’t we then use O2,N2,H2 to store vast amounts of energy so long as they were in deep space and as you say they “can’t radiate” much? Just imagine, we could heat up H2 to a million degrees and hardly no heat would radiate from it.
Smokey:
As a public service, let me give you a tip to help you evaluate the quality of your argument. Imagine the reverse situation: Let’s say that the overwhelming fraction of the peer-reviewed papers say that the human increase in CO2 levels is harmless or even beneficial. Let’s say that this opinion is also expressed in statements by the National Academy of Sciences in the U.S. and the analogous bodies in all the G8+5 nations, by the councils of the AGU, APS, AMS, etc.
However, let’s say that there are environmentalists who disagree and argue that it is just grant funding that is biasing the scientists who are then acting as gate-keepers of the journals, that the NAS and other bodies’ statements just represent a small fraction of their members, etc., etc. As evidence, they cite a petition produced by Greenpeace that bombarded the mailboxes as scientists at academic institutions (and maybe other scientific institutions) across the country (world?) with a propaganda piece arguing how the rise in CO2 is dangerous was and then asked them to sign a petition to this effect. And, let’s say 31000 of scientists did and that they supposedly all had some sort of “hard science” degree.
Can you honestly tell me that you would conclude that there is a consensus that the rise in CO2 is dangerous?
Process does matter, Smokey. It is not always about warping reality to fit your ideological worldview.
My it’s quiet isn’t it. It must be getting late.
davidmhoffer says:
July 21, 2012 at 8:52 pm
If I guess that your original jar was say 1 foot tall, that would be 200,000 blue bb’s in the jar. Still only four in ten thousand, but in this use case, scale matters… Now imagine a photon going from bottom of the jar to the top in a straight line…
=======================================================
Very nice calculation. Now imagine instead of “a photon” let’s say 999,999,999,999,999,999,999,999,999,999,999,999,999,999,999,999,999,999,999,999,999,999,999,999,999,999,999,999,999,999,999,999,999,999,999,999,999,999,999,999,999,999,999,999,999,999,999,999,999,999,999,999,999,999,999,999,999,999,999,999,999,999…… photons. A little bit closer to reality than your “a photon”, you know.
I am looking to your scientific explanation of the destiny of these poor photons.
And please think of a freezer or a frozen chicken as a heating device (see above).
Joel,
Darn it, I lost your comment but the jist was, ” you seem to be arguing that at some point the atmosphere increases in temperature.”
I would agrue that.
Carbon dioxide seems to be getting into the stratosphere. I doubt anyone knows how. Ozone holes? The tops of those thunderheads that dome in? As you undoubtedly know at the tropopause the lapse rate is inverted and temperature increases with altitude, eventually reaching levels nearly as warm as the surface.
I’m going to leave the math to you, but the trouble with, “It’s not difficult to calculate”, and, “It’s simple physics”, is that the reality seems not to be easy or simple.
One could argue for Occam if the empirical evidence for warming suggested anything nearly proportional to CO2 emissions…
David,
First, I am very open minded about your response. I’m not sure that I agree, but I am glad that you posted.
By doing so, you have opened the door for different responses from a whole host of many. I am very interested in how to best interpret my small attempt to represent current data as experimental hands on observations.
OK you want to talk about a 100,000 foot jar vs my 1 foot jar, the concentration will be the same. Why is that different from a warming viewpoint?
Again, I am trying to come up with a visual presentation of the current, past and future concentrations of atmospheric CO2. How can I make this attempt better?
Thank you
davidmhoffer says (July 21, 2012 at 8:52 pm): “I’m not certain why I am still hanging around this thread…”
For what it’s worth, those of us still reading (yes, both of us) appreciate the efforts of both you and RGB. 🙂
davidmhoffer says:
July 21, 2012 at 8:52 pm
Is there a way we could talk some more? Can this site facilitate a connection if you agree?
Policy Guy says (July 21, 2012 at 9:45 pm): “OK you want to talk about a 100,000 foot jar vs my 1 foot jar, the concentration will be the same. Why is that different from a warming viewpoint?”
davidmhoffer was illustrating that a short column of the earth’s atmosphere may transmit most of the IR radiation passing through it, but a column the height of the atmosphere may be essentially opaque. The real life situation is illlustrated in the diagram accompanying Reed’s article, which shows 100% of the earth’s outgoing thermal radiation absorbed by the atmosphere at certain wavelengths (mostly by water vapor and carbon dioxide).
Policy Guy;
OK you want to talk about a 100,000 foot jar vs my 1 foot jar, the concentration will be the same. Why is that different from a warming viewpoint?
>>>>>>>>>>>>>>
Imagine that the yellow bb’s are instead invisible. Look at the jar from the side. You’d see a spec of blue here and there, but you’d have to really look closely to find them. Now look at the jar from the top looking straight down. You would see solid blue.
By doubling the number of blue bb’s from 4 in 10k to 8 in 10k, that blue would become thicker. Photons coming up from the bottom, each carrying a tiny parcel of energy, would spend a lot more time working their way up to escape, and some of them would actually wind up going back down and hitting the bottom of the jar, raising itz temperature higher than it otherwise would have been. So, looking at the blue bb’s from the side makes them look insignificant. Looking at them distributed randomly in a vertical column 50,000 feet tall makes them suddenly look pretty thick, and doubling the number from 4 in 10k to 8 in 10k should obviously make a difference to how long it takes any given photon on average to escape, and also raises the chances that any given photon might bounce around to the point that it gets all the way back down, raising the temperature of the surface.
I think it gets tricky to use this analogy beyond that. By doubling the number of blue bb’s, the math regarding how many times any given photon does what get’s tricky. The point here is that if one starts with 4 and adds 4 to make 8, one would get an effect of X. Will adding 4 more for a total of 12 make it 2X? NO! To get 2X we’d need to add 8 for a total of 16. This is why the IPCC refers to 1 degree of warming per doubling of CO2. They explain in detail that pre industrial concentrations were 280 ppm, and so doubling that would raise the temperature one degree. What they gloss over is that it has been more than a century since we were at 280 ppm. The concentration today is close to 400 ppm. So, to get one more degree out of CO2 from where we are TODAY, we ‘d need to add another 400 ppm which at current rates will take about 2 more centuries. To get 2 degrees, we need to get to 1600 ppm which would take a rather long time.
How to represent that with blue and yellow bb’s, I’m not sure. My original point was to show that scale matters, and makes even a trace gas significant when you consider the entire path from surface to top of atmosphere. To extend the analogy further, we’d want to add red bb’s, about 400 of them per 10,000 yellows, to represent water vapour, because water vapour also absorbs (though not as well) in the same spectrum as CO2. To make matters more complicated still, we’d want to vary the concentration of red bb’s from 400 at the bottom, to a decreasing number of almost zero at the top, because as we rise in altitude, temperature declines, and the amount of water vapour that the atmosphere can hold declines with temperature.
Then, we’d want some way to add still more red bb’s in some ratio over time, because in theory, as the temperature rises, the holding capacity of atmosphere for water vapour also increases, so adding blue bb’s means a bit layer in time we’d have to add some more red ones as well.
Where things seem to fall apart for the warmist side is that the red bb’s aren’t increasing in concentration with temperature as expected. So even though warmer air CAN hold more water vapour, it doesn’t mean that it will, and the latest NASA data seems to show that it is holding LESS not more. I could introduce other aspects of the photons path to space that we could explain with the bb analogy, but as you can see it is getting pretty complicated already and we’ve only scratched the surface in regard to all the factors at play.
My contention is that the real achiles heel of the warmist meme is threefold.
1. The logarithmic nature of CO2 (1 degree of warming per doubling of CO2) means that, based on CURRENT concentrations, we’d have to burn stupid amounts of fossil fuel for centuries to get just a couple of degrees of warming.
2. The IPCC assumes feedbacks from increased water vapour and other factors that give a 3:1 boost to the effects of CO2. We’re certainly not seeing anything close to that, and in fact there is growing evidence that the feedbacks may in fact be negative.
3. All the historical and geological records point to the biosphere being most productive at temperatures warmer than we have today, and human civilization thriving in those temperatures and suffering greatly at lower ones. We can’t eat ice! I’m not afraid of a warmer earth, I embrace it. Unortunately I don’t think we’re capable warming it up enough to matter with CO2 even if we were doing it on purpose.
joeldshore says (July 21, 2012 at 9:25 pm): “However, let’s say that there are environmentalists who disagree and argue that it is just grant funding that is biasing the scientists…”
Um, Joel, there’s no “grant funding” for saying everything is fine, nothing to see, move along… Of course, that hasn’t stopped some “environmentalists” from saying there is. Anthony, how big was this month’s check from Big Coal? 🙂
Policy Guy says:
July 21, 2012 at 10:17 pm
davidmhoffer says:
July 21, 2012 at 8:52 pm
Is there a way we could talk some more? Can this site facilitate a connection if you agree?
>>>>>>>>>>>>>>>
mods, please feel free to pass my email address to Policy Guy.
davidmhoffer says:
July 21, 2012 at 7:25 pm
Every day, hundreds of thousands, perhaps millions, of engineers all over the world use the exact principles and equations that rgb is explaining to design everything from boilers to ovens to nuclear reactors to freezers…. the list is endless. These things work because that’s how the physcis works and if it didn’t, the designs would fail.
—–
Ironically this is one of the reasons why I do not believe the GHG radiative warming effect exists (or if it does exist it only very marginal). If the physics is there why hasn’t an engineer designed an engine to take advantage of the effect?
I challenge anyone – create an experiment which will create a ‘Runaway Greenhouse Effect’ using a synthetic atmosphere which will take advantage of the GHG radiative warming effect. Create any experiment which will take advantage of GHG’s to create an engine which will run on radiative energy alone.