Global Warming: is CO2 the real culprit?

A retired scientist, but one who should definitely know what he is talking about, is questioning whether global warming is due to increased carbon dioxide, or caused by other human induced effects.

F James Cripwell now lives in Ottawa, Canada but started his scientific career working in the Cavendish Laboratory in Cambridge under Sir Gordon Sutherland, the UK's if not the world's leading expert in infra red spectroscopy and the various interactions between infra red (heat) radiation and other substances.

Global warming is undoubtedly caused by some kind of human activity since it correlates strongly with the last century of rapid population and industrial growth. However, there is no complete agreement as to which human activity or activities are mainly to blame.

The culprit most widely considered to be responsible is carbon dioxide, trapping the energy which is input into the earth by the sun, but preventing its re-radiation into space as infra red. However, Jim Cripwell writes, "Assuming the earth is at 290 deg Kelvin, Wien's law shows that the maximum radiation is emitted at 10 microns. Water has a massive infrared absorption band centered on 8.5 microns, and in sufficient quantities that can exist in the atmosphere, absorbs all the radiation in a band from about 7 to 11 microns, accounting for about 70 per cent of the radiation. By contrast, carbon dioxide and methane have a very few intense, narrow absorption bands in this part of the spectrum. Those for carbon dioxide are at about 4 and 14 microns. However, the carbon dioxide absorptions are so intense that all the radiation that it is ever going to absorb is done by about 15 per cent of the atmosphere. So adding more carbon dioxide cannot increase its greenhouse effectiveness. The same is true of methane, except that the concentrations of methane in the atmosphere may be too low for it to have reached its maximum." (According to the US EPA, methane is considered to have a 100 year global warming potential about 21 times as great as that of carbon dioxide, but that is mainly because once it gets into the atmosphere, it tends to stay there). Jim Cripwell continues, "Whatever is causing warming, it is not an increase in levels of carbon dioxide. A more plausible theory is that it is water put into high altitudes by aircraft; this would have roughly the same time line."

Jim Cripwell is not the first person to have made this suggestion, and in view of his knowledge, we consider his comments worthy of consideration.

This is an extended version of a news item which I published in the September 2005 edition of Eureka. Since writing it I have been advised by a distinguished scientist working in an aerospace industry that when all the jets were grounded in the US immediately after 9/11, air temperature dropped by about 1 degree C. I have also been told that weather in the UK shows a weekly cycle, undoubtedly caused by industry in some way. I also note that the centre of London is consistently several degrees C warmer than the suburbs. I therefore suggest that blaming CO2 as being the sole cause of global climate change is simplistic and devoting all efforts to reducing it and doing nothing else at the same time may not achieve much useful result. In fact, I consider it possible that only reducing CO2 emissions could be about as successful in reversing climate change as the ancient Maya Indian practice of sacrificing virgins (and other persons) in the hope of getting it to rain.

In my opinion, we need to understand the problem fully and attack it on all fronts. That would mean reducing waste heat emissions of all kinds, cutting down on the saturation of air by evaporating water from cooling towers and cutting down on emissions from aircraft, particularly at high altitudes. Expanding nuclear power is not an attractive option because it creates a waste disposal problem we still do not have a good solution for, leads to the generation of extra heat, and increases atmospheric water content by evaporation from water cooling the condensers. Wind power, solar power, wave power and hydroelectric power remain good. A hydrogen economy based on hydrogen generated from fossil fuels is not good. Energy economy is good. Instead of turning up central heating in winter we should wear more clothes and instead of turning up the air conditioning in summer, we should enjoy an after lunch siesta on hot afternoons. Instead of rushing around in jet airliners, we should enjoy genteel travel in modern airships, admiring the world from a promenade and getting to know our fellow passengers. For the inter continental movement of heavy cargo, sail power could make a big come back.

Emailed comments for publication in "Eureka" to please and comments for posting here to . Jim Cripwell says he may be contacted at TS

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