[THS] Letters: Arctic sea ice
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Tue May 3 13:34:29 CEST 2011
Letters: Arctic sea ice
Deadly peril of loss of sea ice
Saturday, 12 February 2011
The area of Arctic sea ice in late summer declined substantially in the decade until 2007 and has been stable since then. But in 2010 the area of sea ice which was more than two years old, and was therefore thin ice, was substantially less than ever before.
A reasonable judgment is that there is a 40 per cent chance that the sea-ice area will decline significantly to less than 2.5 million sq km in 2011 and a one in three chance the area will fall to less than 2 million sq km as measured by the Cryosphere Today. The minimum ice area in 2010 was 3 million sq km using Cryosphere Today figures.
Since ice reflects sunlight and water absorbs sunlight, should the ice area decline then the Arctic will warm in late summer. This may well warm the Tundra which will defrost faster than at present. The result will be that the greenhouse gases carbon dioxide and methane will be released into the atmosphere leading to further warming and a runaway greenhouse event and the collapse of civilization.
We believe that should there be a substantial decline in sea-ice area then by marshalling all the resources of humanity and cutting greenhouse-gas emissions substantially and using geo-engineering, then the global climate and civilization can be saved. We need to be ready to start in autumn 2011 if the situation goes badly in late summer 2011.
Emeritus Professor of Engineering Design,
University of Edinburgh
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