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.
Michael Tremblay says: July 23, 2012 at 1:04 am….
Michael, I appreciate that your background as a steam engineer gives you some great insights, but I think you underestimate climate scientists’ understanding of basic science.
“Rather than call it the GHE though, I would rather call it the Atmospheric Effect “
This is simply semantics, not science. We all need to get past the names and think about the concepts. (And I have a problem with “Atmospheric effect” since the atmosphere has MANY effects. The “Greenhouse effect” deals with the IR properties of the atmosphere. If anything, you would want to use terms like “Atmospheric IR effect” and “Atmospheric albedo effect” and “Atmospheric evapooration/condensation effect” ….
“First, it is important to remember that most of the theoretical discussions I have encountered only consider that the atmosphere is mixture of gases.”
That is because that is a simple starting point. Sort of like in most discussions people will say “the boiling point of water is 100C”. But any expert in the field knows that impurities and pressure affect boiling point; any expert will know that there are indeed suspended liquids and solids in the atmosphere.
For example, one of the standard models for radiation in the atmosphere is “MODTRAN” — “MODTRAN® is a “narrow band model” atmospheric radiative transfer code. The atmosphere is modeled as stratified (horizontally homogeneous), and its constituent profiles, both molecular and particulate, may be defined either using built-in models or by user-specified vertical profiles. The spectral range extends from the UV into the far-infrared (0 – 50,000 cm-1), providing resolution as fine as 0.2 cm-1.
“Another problem that I have with climatologists’ interpretation of the AE is that they forget that the atmosphere also reduces the RATE at which the Sun heats the Earth. ”
Again, this is not true. Even the simple “Trenberth cartoon” shows 78 W/m^2 of sunlight getting absorbed by the atmosphere before reaching the earth. And they include reflection by the atmosphere. If the simplest models include the atmosphere reducing incoming sunlight, I am sure more advanced models will too.
“If a CO2 molecule (or any molecule for that matter) is absorbing a photon of a specific frequency and re-emitting a molecule of the same frequency, where is the energy transfer?”
That is subtle, but let me try an explanation.
* A CO2 molecule can gain vibrational energy by absorbing a photon
* A CO2 molecule can gain vibrational energy by colliding with nearby molecules
* A CO2 molecule can lose vibrational energy by emitting a photon
* A CO2 molecule can lose vibrational energy by colliding with nearby molecules
It is important to note that a CO2 molecule could gain energy from a photon and lose that energy via a collision, or vice versa.
If the CO2, the nearby molecules and the source of incoming IR photons are at the same temperature, then these processes will all be in some sort of equilibrium. The CO2 molecule is as likely to gain energy from a photon as it is to lose energy from a photon. It is as likely to gain energy from a collision as it is to lose energy from a collision.
Now suppose you warm up external the source of IR photons. Now there are more incoming photons (at every specific wavelength). Now the CO2 molecule is more likely to gain vibrational energy than lose energy via IR photons. Consequently, these energetic vibrations mean the CO2 is also more likely to lose energy via collisions than to gain energy (since they have more average energy than the surrounding molecules.)
Or think of it this way. Suppose a parcel of N2 is at 250 K and the ground is at 300 K. The CO2 in that parcel is “thermally connected” to the ground via IR photons. The CO2 is also thermally connected to the N2 by collisions. The photons try to warm the CO2 to 300 K (or “try to warm the vibrational mode of CO2 to 300K” if you want to be picky); the N2 tries to cool the CO2 to 250 C. The temperature of the (vibrational modes) CO2 will be somewhere in between. Thus the “warmer” CO2 will warm the cooler N2.
I believe one of the best illustrations of the effect of carbon dioxide on the atmosphere is a graph presented in the Wikipedia article on ‘Radiative Forcing.’ This is a line by line calculation by the MODTRAN webtool hosted by the University of Chicago. It shows the calculated difference between energy escaping the troposphere when the CO2 concentration is 300 PPM, the green curve, and what it would be for 600 PPM, the blue curve. For 95 to 97 percent of the graph, the blue curve runs right over the the green curve indicating almost no difference in heat energy escaping the Earth for a full doubling of the CO2 content. The MODTRAN program was originally developed by the Air Force to calibrate their equipment. It shows the ‘raw’ effect of CO2 on thermal energy escaping the troposphere, given exactly the same atmospheric conditions and surface temperature.
Ref: http://upload.wikimedia.org/wikipedia/commons/9/9c/ModtranRadiativeForcingDoubleCO2.png
I think this plot tells it all. End of story.
Bucky Cochrane says:
July 21, 2012 at 4:12 pm
The whole idea of GHG “absorbing heat” is erroneous. CO2 absorbs a photon, goes into the “bending” mode of molecular vibration and almost immediately radiates the photon which it absorbed. It cannot give up any fraction of this energy; there is no state between this 667 wavenumber excited state and its vibrational ground state.
Absolutely wrong, there are many rotational states between the excited vibrational state and the ground state. During the lifetime of the excited state it endures on average thousands of collisions with neighboring molecules, each of these are capable of reducing the molecule’s energy by an amount equal to the energy difference between energy states. These collisions effectively ‘chip away’ the excitation energy before the molecule can radiate it away and at the same time slightly increase the energy of the collision partners. It’s also possible for the excited molecule to radiate as the result of a rotational transition, i.e. in the microwave range.
It cannot “warm the air” The effect of this re-radiation of 15 micron IR is to take upward directed radiation from the surface of the earth and aim one half of it back to the earth;s surface. Same for any GHG. The downward re-radiated IR then becomes part of the surface radiation budget.
Clearly it does, near the surface the re-radiation only occurs for a small fraction of the excited molecules, at a higher altitude the balance changes.
“You need to prove you key assertion that radiation from a colder body can warm a warmerbody. Radiation is very nice, but you guys apparently can not present any link to a real scientific experiment proving this alleged warming effect, not just radiation.”
Greg thinks that radiation is very nice. He likes radiation from a warmer object more than he likes radiation from a cooler object. He thinks that radiation from a warmer object can warm things, but radiation from a cooler object can’t. Well, maybe he ain’t quite that dumb. Maybe he thinks that radiation from a cooler object has no effect on a warmer object, because the radiation from a cooler object knows it ain’t supposed to warm a warmer object.
Radiation is radiation, Greg. There isn’t one kind that warms things and another kind that don’t. Radiation warms the things that it meets up with, period. It is called radiative heat transfer. People use this stuff to make the world go round, Greg. Try to catch up:
http://www.engineeringtoolbox.com/radiation-heat-transfer-d_431.html
You see that formula for net radiation loss rate, Greg? You better contact the engineers and inform them that they don’t have a clue.
That is all the time I have to waste on you, Greg.
For what it’s worth. The figure entitled “Radiation Transmittd by the Atmosphere” that appears at the start of this post was not not included in the material I sent to Anthony. I’m not sure why Anthony included it; but it’s his blog. As he was kind enough to post my thoughts, I make no complaint. My only intent is to clarify.
Gail Combs says:
July 22, 2012 at 12:48 pm
Konrad says:
July 21, 2012 at 6:11 am
JeffC says: July 21, 2012 at 5:15 am
“GHG does not block radiation, it absorbs and then re-transmits … a better term than block would be slows …”
I believe JeffC to be correct. CO2 almost instantly re-radiates the outgoing IR radiation it intercepts, with around 50% of this radiated back towards the Earth’s surface….
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That is one of the fallacies. 50% is not radiated back towards earth. Think in 3 dimensions not in 2 dimensions because the CO2 molecule and the earth are three dimensional. Also energy can be transferred via collision to other molecules so the energy headed in the direction of the earth is less than 50%.
Firstly, JeffC is wrong, CO2 doesn’t almost immediately re-radiate the outgoing IR radiation, in terms of the collision frequency (~10^9/sec) it takes an age to re-radiate which means most of the CO2 molecules near the surface don’t re-radiate.
Secondly, thinking in 3-D for an atmospheric layer 10km thick around a planet with a diameter of 8000km means that ‘around 50%’ is radiated back towards earth.
Tim Folkerts says:
July 23, 2012 at 7:03 am
Yes. In the same way that I rule out the option that the next time I drop a rock it will fall UPWARD. I “just BELIEVE” it will fall downward. If I do a “fictitious experiment” and say “suppose I let go of a rock in mid air ..” we don’t need to say “Which rock? Have you tested THAT rock before to make sure it will fall? Have to dropped it lots of times to see if it falls every time?”
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I am afraid you thoroughly misunderstood my point about “ruling out the option”. I meant the option that the Spenser’s “experiment” was NOT a description of a real experiment, but was just a fictitious construction with no basis in real experimental physics. Note, he did not even refer to ANY real falsifiable scientific experiment of the kind, this is an indication that NONE ever existed.
Tim Folkerts says:
July 23, 2012 at 7:03 am
Thousands (millions!) of experiments have measured the nature of electromagnetic radiation.
Thousands (millions!) of experiments have measured the IR properties of gases.
Thousands (millions!) of experiments have confirmed the laws of thermodynamics.
…It would be perverse to expect the hot-plate, etc. to disobey well-established rules of physics and suddenly quit conducting/convecting/radiating in the expected manner.
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Again: a colder body does radiate. But there is no law of thermodynamics nor a “well-established rule of physics” saying that a colder body can warm (or reduce cooling of) a WARMER body, in our case by means of radiation.
But it might be possible to make this discovery, why not, just do it and present the scientific falsifiable experimental proof. Spenser and others failed to do that. And please, do not beat around the bush, the point is clear.
Hoser says:
July 21, 2012 at 12:43 pm
I can’t read all the comments to see if these points were already made:
1) The conc of H20 and CO2 vary in the atmosphere; they are not homogeneously distributed.
2) The charts showing absorption clearly indicate the vast majority of the absorption is due to water vapor and not CO2.
3) In the peak of IR emission from the Earth’s surface, Water already absorbs about 2/3 of the energy where CO2 absorbes. The main CO2 band overlaps the shoulder of the main water band.
Point 1 is mostly true, much less so for CO2 than H2O.
Point 2 is not true, it’s certainly not a ‘vast’ majority.
Point 3 is false. See the following for example.
http://i302.photobucket.com/albums/nn107/Sprintstar400/Atmos.gif
Tim Folkerts says:
July 23, 2012 at 7:03 am
“Thousands (millions!) of experiments have measured the nature of electromagnetic radiation.
Thousands (millions!) of experiments have measured the IR properties of gases.
Thousands (millions!) of experiments have confirmed the laws of thermodynamics.
…It would be perverse to expect the hot-plate, etc. to disobey well-established rules of physics and suddenly quit conducting/convecting/radiating in the expected manner.”
Right, Tim. But we have a group of stubbornly ignorant clowns, who think that our understanding of radiative physics has been imposed on us by manipulative climate scientists. It is obvious that climate scientists are not that clever. They couldn’t fool the engineers. And the engineers have been using this stuff for a long time.
http://www.engineeringtoolbox.com/radiation-heat-transfer-d_431.html
Greg House says:
July 21, 2012 at 2:30 pm
Konrad says:
July 21, 2012 at 6:11 am
Outgoing IR radiation radiated back to the Earth’s surface could slow the radiative cooling of surface materials.
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Yes, this is a notion the warmists like very much, but the problem is they can not prove it. I very patently asked them to present a link to a real scientific experiment proving that notion, but they failed
Not only are there experiments but there are products based on this, I’ve given real world examples of it here before. Here’s two examples of the application that are widely used.
Radiation shields for thermocouples, particularly in flame temperature measurements. I first encountered this in 1970 in graduate-level classes, a key reference being a NACA report from the 50’s (forerunner of NASA). We not only learned about it but conducted experiments on the effect and used their heat transfer correlations in the analysis. Such devices are routinely used by engineers.
Light bulbs with an IR reflective coating which causes the filament to heat up and emit more visible.
http://hirheadlights.com/USPTO%20HIR%20bulbs.pdf
http://www.pegasuslighting.com/par38-halogen-ir-light-bulbs-48w-flood-25-degree.html
Come on you guys. Stay sober and stay skeptic. Just look at the results. In my tables.
http://www.letterdash.com/henryp/global-cooling-is-here
No need for any “deeper knowledge” and endless discussions about whether GHG’s cause warming or a delay in cooling. Simple observations at your own weather stations show:
From ca. 1945 the input of energy has been increasing. As has ozone been decreasing.
From ca. 1995 the input of energy has been decreasing. As has ozone been increasing.
There is no AGW. There never was. And the scare of ozone disappearing in the nineties due to anthropogenic activities also was never true. Everything follows on natural parabolic -like curves.
If it gets too cold, pack up, and go, live at a lower latitude. That’s life. It has been.
http://wattsupwiththat.com/2012/07/13/coldest-july-in-history-for-anchorage/#comment-1039049
Phil. says: July 23, 2012 at 7:53 am
Because the outgoing radiation increases as the fourth power of temperature whereas the effect of CO2 is logarithmic. Consequently the stationary point where incoming energy equals outgoing energy goes up but with bounds.
Phil, thank you for your response.
However, I’m not sure I follow your answer. You say the outgoing radiation increases as the fourth power of the temperature whereas the effect of CO2 is logarithmic. It’s not clear what you mean by effect. I’ll assume you mean: “Temperature is proportional to the logarithm of the amount of CO2 in the atmosphere.” If my assumption is incorrect, please let me know; and clarify your meaning. If my assumption is correct, then in the first part of your statement you relate the behavior of the outgoing radiation to the fourth power of the temperature. In the second part of your statement you relate temperature to CO2 levels. Mathematically:
Outgoing radiation = “constant one” times T^4
T = “constant two” times logarithm(CO2 levels)
Doesn’t this imply
Outgoing radiation = “constant one” times [“constant two” times logarithm(CO2 levels)]^4
which to me implies that outgoing radiation should increase (although slowly because of the logarithmic function) with increasing CO2 levels.
In any event, I believe your statement implies that at some combination of CO2 level and temperature, the outgoing radiation (rate of energy loss) equals the incoming radiation (rate of energy absorption). I agree. Since part of my question included the caveat that the rate of incoming radiation is unaffected by the CO2 level, when energy-rate neutrality is reached, CO2 doesn’t “slow down” outgoing radiation. I.e., at best the CO2 “slow down” was transient.
Tim Folkerts “Yes, if you look closely enough you can find IR from room temperature N2 and O2, but it is orders of magnitude less intense than the IR from CO2, O3, CH4, etc”.
Thanks Tim, but you havn’t given me experimental evidence to back that up.The experiment I was considering was impracticable but this is more manageable: create a vacuum in a metal chamber cooled down to near absolute zero (like deep space); introduce a jet of diatomic N2 at 15c into the chamber and measure the watts of IR coming off the the jet . Do the same for triatomic Co2. You say CO2emission of IR is orders of magnitude higher, could be, I’m not sure about that.
Greg says: “But there is no law of thermodynamics nor a “well-established rule of physics” saying that a colder body can warm (or reduce cooling of) a WARMER body, in our case by means of radiation. ”
Ah … “proof by bold assertion”. But I can just as well assert that there IS such a rule. And since the three PhD physicists that I know who have been participating in this discussion all think the cold object CAN slow the cooling of a warmer body (and have given varying degrees of explanation), I go with the bold assertions of the PhDs.
The “rule” is actually quite simple. The warm object emits radiation as a function of its own temperature (independent of anything else going on around it: P_out = (epsilon)(sigma)(Area)(T^4) ). As you admit, the cold object does radiate at least a bit. And at least some of that radiant energy gets absorbed by the other (warmer) object: Call it P_in_from_cold. In the absence of the cold object, the warm object would be receiving from that direction a smaller amount of energy: call it P_In_from_3K_Space.
The net change with the cold object nearby is
[P_in_from_cold – P_out ] (a negative number = cooling]
The net change without the cold object nearby is
[P_in_from_space – P_out ] (a bigger negative number = morecooling]
The cool object keeps the warm object from cooling as rapidly as it would without the cool object nearby. (or with a heater like the sun present, the equilibrium temperature is higher with the cooler object nearby than it would be with the even colder outer space nearby.)
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Maybe that is the best way to think of it. The earth is being warmed by the sun. It could be cooled by either
* surrounding it by ~250 K atmosphere
* surrounding it by 3 K outer space.
Anything warmer than 3 K (the background radiation of space) will keep the earth warmer than it would be with that 3 K background instead. (Like your skin staying warmer when surrounded by 20 C air rather than -20 C air).
Phil. says:
July 23, 2012 at 9:21 am
Not only are there experiments…
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Yeah, just present a link to a real genuine falsifiable scientific one. It is not enough to say “they are there”.
Phil. says:
July 23, 2012 at 9:21 am
…but there are products based on this, …Light bulbs with an IR reflective coating which causes the filament to heat up and emit more visible.
http://hirheadlights.com/USPTO%20HIR%20bulbs.pdf
http://www.pegasuslighting.com/par38-halogen-ir-light-bulbs-48w-flood-25-degree.html
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Look, just multiplying the claim is no proof of the claim being correct.
The manufacturer CLAIMS his bulb is more efficient, the same goes for the patent. Now, WHERE IS THE SCIENTIFIC PROOF FOR THAT? Nowhere, apparently.
We are talking about science here, not about marketing.
Tim>> you can find IR from room temperature N2 and O2, but it is orders
Tim>> of magnitude less intense than the IR from CO2, O3, CH4, etc”.
Paul> Thanks Tim, but you havn’t given me experimental evidence to back that up.
Sorry — I considered this “common knowledge” for people interested in IR. I didn’t feel i needed to give evidence.
The simplest evidence is the image at the very top of this post, showing absorption of various wavelengths by various gases. They didn’t forget about N2 — it simply is not important at visible or IR wavelengths.
You can also study the quantum mechanics of molecular energy levels. They are quite good at predicting the spectra of molecules. And the theory says molecules that can bend (3+ atoms) or that have a dipole moment (eg HF) will have strong IR lines. Molecules with no bending and no dipole moment (eg N2) will have no IR lines. (In reality there can be weak induced dipole moments in N2, so tit can have weak IR lines).
House, it’s time to put it to rest.
It appears obvious to me that you may be a troll trying disrupt this thread.
Greg House has still not responded to my challenge to produce links to verifiable experiments proving that the earth is round and the earth circles the sun.
Tim Folkerts says:
July 23, 2012 at 9:57 am
Greg says: “But there is no law of thermodynamics nor a “well-established rule of physics” saying that a colder body can warm (or reduce cooling of) a WARMER body, in our case by means of radiation. ”
Ah … “proof by bold assertion”. But I can just as well assert that there IS such a rule. And since the three PhD physicists that I know who have been participating in this discussion all think the cold object CAN slow the cooling of a warmer body (and have given varying degrees of explanation), I go with the bold assertions of the PhDs.
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I do not need to prove anything. You guys failed to present an experimental proof for your assertion. Even on the theoretical level you are just generally talking about lows and rules without proving that they support your assertion.
RE: Greg House:(July 23, 2012 at 8:45 am)
Again: a colder body does radiate.
That is not quite true . . . The colder body just does not radiate as much. The standard IPCC thermal budget diagram for the Earth shows 390 W/m² leaving the surface with 324 W/m² returning from the cooler atmosphere above so that the surface sees a net loss of 66 W/m², by radiation to the upper atmosphere. The atmosphere is actually radiating 265 W/m² to outer space. The extra 200 W/m² or so is partially delivered from the surface by convection and transpiration and, based on this diagram, about 67 W/m² is from direct solar heating.
Of course, the carbon dioxide band is dead, but again, that is like a one foot diameter tree in the middle of a ten-foot wide stream. Water vapor appears to be a leaky greenhouse gas, probably due to condensing accelerated convective activity.
REF: http://www.windows2universe.org/earth/Atmosphere/images/earth_rad_budget_kiehl_trenberth_1997_big.gif
Also, a colder body can reflect heat from a warmer body without being warmed by the reflected radiation.
Tim Folkerts says:
July 23, 2012 at 9:57 am
the cold object does radiate at least a bit. And at least some of that radiant energy gets absorbed by the other (warmer) object: Call it P_in_from_cold. …The cool object keeps the warm object from cooling as rapidly as it would without the cool object nearby…
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You do understand, that a repetition or rephrasing of the same unproven claim is not a scientific proof that this claim is scientifically correct, don’t you?
OK. So O2 and N2 do not absorb IR energy- they are considered transparent to visible and IR in “conventional” NASA-GISS-CAGW theory. And, apparently, in the calculations used in descriptions of their CAGW models.
A question not addressed yet.
Assume 1370 watts are present at the top of atmosphere at the equator.
Approximately 360 watts are absorbed by the atmosphere before reaching the ground. What absorbed that 360 watts that are NOT transmitted, and where does that energy “go” if O2 and N2 do not radiate or absorb IR energy?
Greg House;
You do understand, that a repetition or rephrasing of the same unproven claim is not a scientific proof that this claim is scientifically correct, don’t you?
>>>>>>>>>>>>>>>
Since your entire diatribe in this and other threads consists of responding to all explanations to you with “that’s not proof, I asked for proof” your statement is rather amusing. And you still haven’t responded to my challenge to produce verfiable proof of the same sort you have asked for that the earth is round and circles the sun. If you can’t, I presume you to be of the opinion that the earth is flat and that the sun circles the earth.
I have, by the way, posted multiple times, a link to an experiment that shows exactly what you are asking for. You don’t comment on it because you don’t have the basic understanding of physics required to even begin discussing if it proves my point or not. In this case the experiment I linked to is in fact valid. But your understanding of physics is so primitive that you don’t actually know, so you don’t comment. I could have chosen an experiment that was totaly bogus in this regard, and you would have ketp your yap shut on that one because you wouldn’t understand it either, and so you’d simply ignore it just like you do the dozens of actual proofs that you’ve been presented with. Your objections are rooted in blinding ignorance which you display a remarkable determination to maintain.
Set/GregHouse=Ignore