Monday, July 21, 2008

Warming West is ground zero for wildfires

San Francisco Chronicle: California has been hit by 2,000 fires this year, and climate scientists are predicting that the situation will worsen as temperatures rise. The American West has been warming dramatically during the past 60 years at a rate surpassed only by Alaska. This year has been particularly dry for California, with less snowfall, earlier snowmelt and lower summer river flows.

Some of the state's top scientists say the changing water picture is caused by humans producing greenhouse gases, and the U.N. Intergovernmental Panel on Climate Change predicts more intense and longer droughts with warmer spring and summer temperatures in the West. That, scientists say, leads to increases in the length of the fire seasons, number of fires, time needed to put out the fire and size of the burned area.

"The snow melts sooner, the dry season gets longer and rivers crest earlier. That gives more of a chance for drying out and therefore a likelihood of more fires," said Tim Barnett, a climatologist at the Scripps Institution of Oceanography at UC San Diego who led research on the effects of greenhouse gases on the changing hydrology in the western United States. "If you look at where we will be in 20 or 30 years, we'll have serious problems," he said.

...The study concluded that "in light of recent alarming projections for increased temperatures and fire-season length by the end of the century," it is time to rethink the current policy of suppressing fires and, under the proper circumstances, let more fires burn to reduce problem fuels.

Simi Valley fire from 2003, US Air Force, Wikimedia Commons

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