Tuesday, April 18, 2006

The Climate Debate: A Postscript

In my most recent posts about the climate debate (here and here), I forgot to note a suppressed article about greenhouse gases, which has been rescued from oblivion and republished here and here. Some excerpts:

According to Vladimir Shaidurov of the Russian Academy of Sciences, the apparent rise in average global temperature recorded by scientists over the last hundred years or so could be due to atmospheric changes that are not connected to human emissions of carbon dioxide from the burning of natural gas and oil. . . .

Shaidurov has used a detailed analysis of the mean temperature change by year for the last 140 years and explains that there was a slight decrease in temperature until the early twentieth century. This flies in the face of current global warming theories that blame a rise in temperature on rising carbon dioxide emissions since the start of the industrial revolution. Shaidurov, however, suggests that the rise, which began between 1906 and 1909, could have had a very different cause, which he believes was the massive Tunguska Event, which rocked a remote part of Siberia, northwest of Lake Baikal on the 30th June 1908. . . .

Global warming is thought to be caused by the "greenhouse effect". Energy from the sun reaches the earth's surface and warms it, without the greenhouse effect most of this energy is then lost as the heat radiates back into space. However, the presence of so-called greenhouse gases at high altitude absorb much of this energy and then radiate a proportion back towards the earth's surface. Causing temperatures to rise. . . .

[T]he most potent greenhouse gas is water, explains Shaidurov and it is this compound on which his study focuses. According to Shaidurov, only small changes in the atmospheric levels of water, in the form of vapour and ice crystals can contribute to significant changes to the temperature of the earth's surface, which far outweighs the effects of carbon dioxide and other gases released by human activities. Just a rise of 1% of water vapour could raise the global average temperature of Earth's surface more then 4 degrees Celsius.

The role of water vapour in controlling our planet's temperature was hinted at almost 150 years ago by Irish scientist John Tyndall. Tyndall, who also provided an explanation as to why the sky is blue, explained the problem: "The strongest radiant heat absorber, is the most important gas controlling Earth's temperature. Without water vapour, he wrote, the Earth's surface would be 'held fast in the iron grip of frost'." Thin clouds at high altitude allow sunlight to reach the earth's surface, but reflect back radiated heat, acting as an insulating greenhouse layer.

Water vapour levels are even less within our control than CO levels. According to Andrew E. Dessler of the Texas A & M University writing in 'The Science and Politics of Global Climate Change', "Human activities do not control all greenhouse gases, however. The most powerful greenhouse gas in the atmosphere is water vapour, he says, "Human activities have little direct control over its atmospheric abundance, which is controlled instead by the worldwide balance between evaporation from the oceans and precipitation."

As such, Shaidurov has concluded that only an enormous natural phenomenon, such as an asteroid or comet impact or airburst, could seriously disturb atmospheric water levels, destroying persistent so-called 'silver', or noctilucent, clouds composed of ice crystals in the high altitude mesosphere (50 to 85km). The Tunguska Event was just such an event, and coincides with the period of time during which global temperatures appear to have been rising the most steadily - the twentieth century. There are many hypothetical mechanisms of how this mesosphere catastrophe might have occurred, and future research is needed to provide a definitive answer.

Read the whole thing. Also read John Ray's Greenie Watch, where Ray posts daily updates about unscientific "science" in the service of the Left's anti-humane agenda.

Related posts:
Global Warming: Realities and Benefits
Words of Caution for the Cautious
Scientists in a Snit
Another Blow to Climatology?
Bad News for Politically Correct Science
Another Blow to Chicken-Little Science
Bad News for Enviro-nuts
The Hockey Stick Is Broken
Science in Politics, Politics in Science
Global Warming and Life
Words of Caution for Scientific Dogmatists
Hurricanes and Global Warming
Global Warming and the Liberal Agenda
Debunking "Scientific Objectivity"
Hurricanes and Glaciers
Remember the Little Ice Age?
Science's Anti-Scientific Bent
A Possibly Useful Idiot