Friday, December 3, 2010

Heat waves may “become norm” by 2100

Environmental Research Web: Extreme weather like the heat waves in Russia this year, and in Europe in 2003, will make the impacts of climate change clear to humanity, according to David Easterling. In part that's because by the end of the 21st century the events that are currently considered heat waves will become commonplace, warns the chief of the scientific services division at the US National Climatic Data Center (NCDC).

“We're finding that the length of the heat waves gets to the point where it almost becomes the norm in model situations towards the end of the 21st century,” Easterling explained. “In a lot of places the temperatures warm up to that point just about every day.”

These interim results from Easterling's latest research typify his keen interest in extreme climate events. Given the high profile of such phenomena, he is used to fielding questions about whether climate change has caused an individual event. While the stock answer is: “no, but it increases the chances”, he wants to try to pin down more direct relationships. “We want to be a little more specific and ask 'Can we say anything about the heat waves in Russia?', for example,” Easterling told environmentalresearchweb.

A group at the NCDC's parent organisation, the US National Oceanographic and Atmospheric Administration (NOAA) is helping address this question. The researchers use models to study an event and look for signals to indicate that climate change has raised the temperature during a heat wave. “It's a tough nut to crack,” Easterling admitted. “You have to use both observations and model simulations to see how much of that heat wave was due to climate change rather than just chance or circulation of the atmosphere.”…

A bimetal thermometer, shot by 1-1111, Wikimedia Commons, under the Creative CommonsAttribution-Share Alike 3.0 Unported license

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