Sunday, January 11, 2009

Snowstorms don’t mean climate change threat has passed: expert

Travis Lupick in the Straight (Vancouver): British Columbia’s holiday snowstorms drove everybody crazy. But, apparently, no one more so than climate scientists. “Every time there is a freaking snowfall, it seems like everybody is going, ‘What’s going on?’” Andrew Weaver told the Straight. “It’s frustrating as a climate scientist.”

Weaver, a climate-modelling expert at the University of Victoria and a lead author with the Intergovernmental Panel on Climate Change, explained that whenever a cold streak hits, some people question accepted theories of climate change and grow skeptical about global warming. But a few days of snow does not mean that the Earth is not getting warmer.

“People mix up weather and climate,” Weaver said in a telephone interview from Victoria. He described weather as what is here and now, like the sun shining or rain falling. Climate, on the other hand, is more long-term.

Weaver explained climate change as a “shift in the distribution of the likelihood of the occurrence of weather events towards the warm”. He continued, “What that means is it doesn’t mean that it will never be cold; it means that the likelihood of it being cold diminishes with time, and the likelihood of it being extremely warm increases with time.”

A probable reason for 2008’s cold snap is La Nina, according to Weaver. He explained that El Nino is a warm phase of atmospheric interaction and La Nina is the opposite—a cold phase. “So there is overall warming, but it is not happening in a straight line; it oscillates as we go up,” Weaver said.

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