Posted on 01/08/2013 1:10:25 PM PST by kathsua
The claim that carbon dioxide (CO2) can increase air temperatures by "trapping" infrared radiation (IR) ignores the fact that in 1909 physicist R.W. Wood disproved the popular 19th Century thesis that greenhouses stayed warm by trapping IR. Unfortunately, many people who claim to be scientists are unaware of Wood's experiment which was originally published in the Philosophical magazine , 1909, vol 17, p319-320.
Philosophical Magazine might not sound like the name of a science publication, but a century ago leading scientists published their discoveries in it.
During the early 19th Century many physicists supported the theory postulated by Benjamin Franklin that heat involved some type of fluid. The theory became known as "caloric theory". Joseph Jean Baptiste Fourier's theory that the atmosphere was heated from infrared radiation from the ground was a variation of caloric theory with IR functioning as the "fluid". Fourier believed greenhouses were heated by trapping this radiation.
Physicists in the early 19th Century were attempting to develop theories to explain the nature of atoms and their properties such as heat. Physicists theorized that atoms were the smallest particles of matter.
By the end of the century a new theory of heat, called "kinetic theory", was being developed that suggested heat was the motion, or kinetic energy, of atoms. However, Fourier's theory that IR heated the atmosphere particularly by interacting with carbon dioxide and water vapor continued to have support.
In 1897 J.J. Thompson overturned the popular theory of the atoms being the smallest particles of matter by reporting his discovery of the electron and predicting two other types of charged particles he called protons and neutrons.
Wood was an expert on IR. His accomplishments included inventing both IR and UV (ultraviolet) photography. In 1909 he decided to test Fourier's theory about how greenhouses retained heat.
Wood constructed two identical small greenhouses. The description implies the type of structure a gardener would refer to as a "cold frame" rather than a building a person could walk into.
He lined the interior with black cardboard which would absorb radiation and convert it to heat which would heat the air through conduction. The cardboard would also produce radiation. He covered one greenhouse with a sheet of transparent rock salt and the other with a sheet of glass. The glass would block IR and the rock salt would allow it to pass.
During the first run of the experiment the rock salt greenhouse heated faster due to IR from the sun entering it but not the glass greenhouse. He then set up another pane of glass to filter the IR from the sun before the light reached the greenhouses.
The result from this run was that the greenhouses both heated to about 50 C with less than a degree difference between the two. Wood didn't indicate which was warmer or whether there was any difference in the thermal conductivity between the glass sheet and the rock salt. A slight difference in the amount of heat transfered through the sheets by conduction could explain such a minor difference in temperature. The two sheets probably didn't conduct heat at the same rate.
The experiment conclusively demonstrates that greenhouses heat up and stay warm by confining heated air rather than by trapping IR. If trapping IR in an enclosed space doesn't cause higher air temperature than CO2 in the atmosphere cannot cause higher air temperatures.
The heated air in the greenhouses couldn't rise higher than the sheets that covered the tops of the greenhouses. Heated air outside is free to rise allowing colder air to fall to the ground.
Atmospheric CO2 is even less likely to function as a barrier to IR or reflect it back to reheat the ground or water than the sheet of glass in Wood's greenhouse.
The blackened cardboard in Wood's greenhouses was a very good radiator of IR as is typical of black substances. The water that covers 70% of earth's surface is a very poor radiator and produces only limited amounts of IR as is typical of transparent substances. Water releases heat through evaporation rather than radiation.
The glass sheet provided a solid barrier to IR. Atmospheric CO2 is widely dispersed comprising less than 400 parts per million in the atmosphere. Trapping IR with CO2 would be like trying to confine mice with a chain link fence.
Glass reflects a wider spectrum of IR than interacts with CO2. The glass sheets reflected IR back toward the floor of the greenhouse. CO2 doesn't reflect IR.
At the time of Wood's experiment, it was believed that CO2 and other gas molecules became hotter after absorbing IR.
Four years later Niels Bohr reported his discovery that the absorption of specific wavelengths of light didn't cause gas atoms/molecules to become hotter. Instead, the absorption of specific wavelengths of light caused the electrons in an atom/molecule to move to a higher energy state. After absorption of light of a specific wavelength an atom couldn't absorb additional radiation of that wavelength without first emitting light of that wavelength. He called the amount of energy absorbed and emitted as a "quantum". (Philosophical Magazine Series 6, Volume 26 July 1913, p. 1-25)
Unlike the glass which reflects IR back where it comes from, CO2 molecules emit IR up and sideways as well as down. In the time interval between absorbing and reemitting radiation, CO2 molecules allow IR to pass them by. Glass continuously reflects IR.
Those who claim that CO2 molecules in the atmosphere can cause heating by trapping IR have yet to provide any empirical scientific evidence to prove such a physical process exists. The experiment by R.W. Wood demonstrates that even a highly reflective covering that reflects a broad spectrum of IR cannot cause heating by trapping IR in a confined space. There is no way CO2, which at best only affects a small portion of the IR produced by earth's surface, can heat the atmosphere by trapping IR.
Contrary to the lie repeated in news stories about climate, science doesn't say that CO2 is causing higher temperatures by trapping IR. Empirical science indicates that no such process exists in this physical universe.
Is all of science a fraud which allows people to get money by making false claims?
Environmentalists have a pathological hatred and fear of economic progress and industrial civilization and fanatically believe in the intrinsic value of nature,and so the claims of environmentalists are filled with dishonesty, and they will reach for whatever is at hand that will serve to frighten people in order to succeed in achieving their agenda.
Scientists today are interested in getting as much government grant money as possible to fund their mostly useless “work.” They are dishonest Takers as surely as is a Welfare cheat.
The theory of CO2-driven AGW is bogus — but, not for the reasons stated in the article.
Putting this together, it seems there must be a small calculable amount of IM coming back to earth, though most of it escapes...which is the impression I had before I became aware of these details. Loosely speaking then, a small amount of IM is "reflected" by CO2.
In the first place, IR is not energetic enough to cause electrons to change energy levels. IR produces a change in the vibrational energy state of CO2 molecules. The vibrational internal motion is easily converted to translational motion during molecular collision, which increases temperature.
This is well established, and any college freshman chemistry lab (and many Chem II course in High School) demonstrate IR spectroscopy of substances; typically CO2 is one of them. The fact that CO2 absorbs IR and translates this into heat is basic science and is NOT disputed by anyone serious.
At fundamental issue is this: since CO2 is a very poor absorber (it absorbs vibrational energy in only three narrow bands, with about 8% efficiency) and since humans are known to account for a VERY small percentage of CO2 in the atmosphere, AGW alarmists have posited an out-of-control feedback mechanism which purports to show that as CO2 from human sources is released into the atmosphere, increasing warming, it leads to more CO2 being released by natural sources which in turn leads to more warming etc, etc, etc.
The problem is that this forcing feedback mechanism has not been convincingly shown to exist in the existing models, and even the models don't agree on how large it would be because there are so many aggravating and mitigating factors involved that have nothing to do with CO2. [And some, like the extinction theorem distance, that do have to do with CO2 that we're not sure we are modelling very well.]
A number of experiments at Cornell University have not shown any increase in the release of soil carbons ("black carbon") in response to warming. That is a major blow to AGW alarmists.
Claiming that IR cannot heat the atmosphere is ridiculous, and on a level with the idiotic claims that living organisms "violate" the Second Law of Thermodynamics, or that atoms cannot exist because of the mutual repulsion of protons. This kind of crap is silly and makes conservatives look foolish. The question of AGW is complicated and for people who want serious ammunition for their counterarguments this kind of drivel is not helpful.
CO2 absorbs and reflects IR in three very narrow bands with a thermal efficiency of about 8%. The IR excites vibrational energy levels in CO2 molecules. That vibrational energy can be imparted to other gas molecules during collisions, producing heat, but most of it is re-emitted as IR (that's the part of it that's reflected.)
There is NO dispute that this effect occurs.
Thanks I thought it was bogus.
But what about this?
http://arxiv.org/PS_cache/arxiv/pdf/0707/0707.1161v4.pdf
Thank you. I suspected so before. Your input makes me even more dubious about the article. It smelled like quackery to me, but I was hoping some more scientifically knowledgeable Freeper would confirm my suspicion.
I also agree that global warming alarmism is pretty much bunk, but should be countered with well reasoned and informed arguments rather than quackery.
Here is what happens: 1) A CO2 molecule absorbs a photon of light in the infrared (IR) region of the spectrum. 2) A CO2 molecule can vibrate in a number of different directions (or modes.) The absorbed IR photon causes the molecule to jump to a more energetic vibrational mode 3) The excited vibrational state is "unstable," because there is a lower state (the one the CO2 molecule was in until a moment ago) so after a brief period of time, the molecule re-emits the photon. 3a) IF during this brief period of time, the CO2 molecule collides with another atom or molecule, the energy can be transmitted duing the collision, instead of re-emitting as a photon.
If (3) happens, you have "reflection." It is what happens "most" of the time, and there is no heat transferred to the atmosphere; it just goes back out into space. If (3a) happens, the colliding molecules pick up speed, and there is heat.
Here is a decent explanation of what would be covered in a freshman general chemistry class. http://www.wag.caltech.edu/home/jang/genchem/infrared.htm
That is actually a famous article, and has been repeatedly attacked by warming alarmists. It brings up many — but not all — of the substantive objections to AGW. It does not, for example, address the inadequacy of the computer models, just the inadequacy of the physical ones.
ALWAYS FOLLOW THE MONEY!!
Keeping the global warming myth alive is putting money in the pockets of some very influential people.
Just like that dumb idea of alcohol from corn and the defacing of once-beautiful America with ugly windmills.
Kachiiiing.
This doesn't follow. Atmospheric CO2 at sea level has an "optical depth" in the IR of several hundred meters, I think it is ... on that order. In fact, the opposite objection is often raised : that the atmospheric CO2 is "optically thick", considered over its whole height, so making it slightly "thicker" will not cause any additional trapping. Of course, there is an answer to this, but I forget it.
This whole area is replete with reversals of logic such as this, like the old "fortunately, unfortunately" story, so I always think there is certainly room for skepticism, but this box experiment won't do it!
“Thanks I thought it was bogus.”
Hey! I had nothing to do with it!
Besides, it was released today that last year was the warmest year on record.
But China today announced the coldest winter on record.
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