Friday 27 June 2008

Hole in the Ozone Layer Protects Antartica from Global Warming

Things never exist in isolation. I posted earlier this week about the hole in the ozone layer. I came across this article today:


(reproduced from http://www.sciam.com/article.cfm?id=updates-jul-08&sc=rss)

Ozone Recovery, Warmer Antarctica
The Antarctic ozone hole that forms every spring has kept that continent's interior cold even as the rest of the world has warmed over the past few decades [see "A Push from Above"; SciAm, August 2002]. Thanks to the global ban on chlorofluorocarbons, stratospheric ozone levels there are slowly recovering. A repaired hole, however, could speed Antarctic ice melting and change weather patterns, according to a computer model by Judith Perlwitz of the University of Colorado at Boulder and her colleagues. With more ozone, the lower stratosphere would absorb more ultraviolet light and warm up by as much as nine degrees Celsius. That in turn would break down circulation patterns that trap cold air over Antarctica's interior, making the continent heat up. The changed patterns would also make Australia warmer and drier, and South America could get wetter. Such ozone details may need to be worked into global climate models, most of which have neither incorporated such effects nor included enough of the stratosphere. The journal Geophysical Research Letters published the study on April 26.

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