Editor's note: Please feel free to link to, or copy and paste. Joel Kauffman gives his permission for any type of cross-posting with proper attribution.
Hammered by evidence (link 13) that carbon dioxide levels above 300 ppm do not cause global warming, climate fear mongers have brought up methane as a serious “greenhouse gas” we should all worry about.Most of the fears are stoked by claims that methane is a more serious “warmer” than carbon dioxide. From the top down, the factor by which methane is a “greater danger” than carbon dioxide varies.
The U.S. Geological Survey Energy Resource Surveys Program posted (Link 2) that: “According to recent estimates, atmospheric methane accounts for about 15 percent of the "radiative forcing" added to the atmosphere. Methane as a molecule contributes about 70 times more radiative forcing, by weight, than does carbon dioxide, but its short residence time of 8 to 12 years in the atmosphere, (about 5 percent that of carbon dioxide), means that reductions in methane emissions will have significant short-term benefits.”
David Blume, author of Alcohol Can Be a Gas actually cites on p62 the utterly discredited IPCC of the UN for the outlandish claims (Link 1) that methane is 62 times as potent as carbon dioxide as a “greenhouse gas”.
And http://www.nature.com posted (Link 4) that: “Methane is a far more effective global warmer than carbon dioxide and last year saw another 27 million tonnes of it in the atmosphere after a decade of no change…”
David Chandler, MIT News Office (Link 3)wrote: “Given that, pound for pound, methane is 25 times more powerful as a greenhouse gas than carbon dioxide, the situation will require careful monitoring in the near future.”
In an unsigned posting, http://www.America.gov wrote that: “Over 200 years, methane concentrations (Link 5) in the atmosphere have more than doubled, largely because of human activity. Methane is 23 times better at trapping heat in the atmosphere than is carbon dioxide, so reducing methane emissions is a good short-term way to address global warming.” In an unsigned and undated posting, the EPA wrote (Link 6) that: “Methane is about 21 times more powerful at warming the atmosphere than carbon dioxide (CO2) by weight. A recent study by Dlugokencky, et. al. shows that atmospheric methane has been at a steady state of 1751 ppbv (1.8 ppm) between 1999 and 2002.” EPA used ppbv (parts per billion by volume) to have a bigger number.
Richard Black, Environment correspondent, BBC News website, (Link 7) wrote that: “The gas is about 20 times more potent than carbon dioxide in terms of its warming effect.”
Dr. William Dillon, U.S. Geological Survey, (Link o8) wrote: “Methane, a ‘greenhouse’ gas, is 10 times more effective than carbon dioxide in causing climate warming.”
NASA wrote: (Link 9) “Methane is second only to carbon dioxide in contributing to global warming. It is a naturally occurring gas, a product of a variety of biological processes.”
Chris Colose, (link 10) on 10 Nov 08, wrote: “As you can see, CO2 is actually much more efficient than methane at cutting off the outgoing longwave radiation [from the Earth]. That is, intrinsically speaking, methane is not as good a greenhouse gas as carbon dioxide.”
Monte Hieb, (Link 11) on January 10, 2003, wrote: “Water vapor constitutes Earth's most significant greenhouse gas, accounting for about 95% of Earth's greenhouse effect (4). Interestingly, many ‘facts and figures' regarding global warming completely ignore the powerful effects of water vapor in the greenhouse system, carelessly (perhaps, deliberately) overstating human impacts as much as 20-fold.”
Have you ever seen a better reduction to an absurdity? Among these 11 posts, which is correct? None overall.
The greenhouse gas theory says that emission of infrared radiation from the Earth is absorbed by certain gases in the atmosphere, which heats them up. For this to happen, the wavelengths emitted by the Earth, a broad swath peaking at 20 microns, can only be absorbed by a gas with a broad swath peaking at 20 µ microns (from 3-30 µ).Here the champion absorber is water vapor. A minor absorption peak of carbon dioxide at 13 µ absorbs, but its major peak at 4 µ does not. The major peak of methane (Link 12) at 3 µ (3000 cm-1) is too far away from Earth’s emission to matter, but its smaller absorption at 8 µ (1300 cm –1) might absorb a little.
Please note comment by Derek Adler - This is a spectral plot of HUMID air, the only one I am aware of at present.
How much might this matter? In Figure 7 of the review:“Climate Change Reexamined” (Link 13) you can see an infrared spectrum of humid air.
Look near 3 µ or 3000 cm-1 for the major infrared peak of methane. Do you see any of it?
There is none.
This means that at its level of only 1.8 ppm in air, methane is not a significant absorber.
This means it cannot be an active “greenhouse gas”.
This is good science.
Comments by Derek Adler:
IR spectra are in general quite confusing, but the simplest way to understand Dr. Kauffman's figure 7 above and in his Climate Change Reëxamined pdf is to remember, the effect of the greenhouse gases present, or rather the size of the combined contribution overall, is the size of the response shown in the spectral plot. Water vapour in Fig. 7 has a strong response in several areas of the spectrum shown relevant to earth's outgoing ("heat") long wave radiation.
There is generally a very large amount of water vapour present, approximately 1,000 to 30,000 parts per million (ppm).Carbon dioxide has a smaller spectral response in these wavelengths, and is present in far smaller quantities than water vapour, commonly varying between 300 to 400 parts per million. From the above it is apparent that water vapour is a far more powerful (in spectral response terms) and more common as a greenhouse gas contributor.This is why water vapour is THE most important greenhouse gas.
Methane by comparison has a very small spectral response in Fig 7, and is present in levels best expressed as parts per billion. Expressed in parts per million methane is present in approximately 1.8 ppm, not eighteen, but one point eight parts per million.Which is exactly what Dr Kauffman's Fig 7 shows, I have added arrows to Fig 7 (above) to "point out" where on the plot methane's actual contribution to the greenhouse effect should show up....
Commonly "alarmists" will counter the above with tales of impending doom due to soon to be released vast amounts of methane due to (hoped for ! ! ! ) melting of Arctic tundra.
Courtesy of Christopher Monckton: "Froese et al. investigated ground ice in the permafrost zone of Canada's Yukon Territory. They found that the ash layer on top of the ice was 740,000 ± 60,000 years old, meaning that the ice and any methane clathrates in the ice have survived several cycles of warmth. Froese DG, et al., Ancient permafrost and a future, warmer Arctic. Science 2008;321:1648."
The (hoped for by AGW proponents) melting of Arctic tundra does not appear at all likely...
Below is a link to recent research that shows how little we understand about the processes that effect the levels of atmospheric methane. The oceans as the research undoubtedly shows are a major player, that is usually not even mentioned. http://www.newscientist.com/article/dn14211" more ozone and methane being destroyed than we previously thought, " says Alastair Lewis of the National Centre for Atmospheric Science in Leeds, UK.
Given that global levels of methane have NOT run away, and are NOT rising equally with man's supposed emissions of methane through his various activities, i. e., beef and milk production (cows are rather flatulent, but pleasant creatures), then the level of our understanding at present becomes all too easily misrepresented. At best our knowledge of these processes is rudimentary, and probably missing some of the main factors. Anybody proclaiming doom from the "present consensus" understanding is obviously being alarmist from a position that is known to be at best "out of date."
http://www.imakemygas.com/immg_hydrogen ... Ggodwnf7mQ
http://www.blogs.nature.com/news/thegre ... ws_me.html
http://www.america.gov/st/washfile-engl ... 53449.html
http://marine.usgs.gov/fact-sheets/gas- ... title.html
http://www.gsfc.nasa.gov/topstory/20020 ... house.html
http://chriscolose.wordpress.com/2008/1 ... e-and-co2/