Tuesday, September 18, 2012

Study: Western wildfires burning bigger, season lasting longer

The number of wildfires larger than a thousand acres has doubled across much of the West since the 1970s and the trend doesn’t show any signs of slowing, according to a new climate study. Over the past decade, the average annual burn has been at least 2 million acres on U.S. Forest Service land, according to records studied by the research group Climate Central. That’s a scar the size of Yellowstone National Park. In addition, the West’s forest fire season has extended by 75 days compared to 40 years ago. “We’re seeing a clear change, with bigger fires starting earlier, showing longer fire durations,” Jennifer Marlon of the Yale School of Forestry and Environmental Studies said in a conference call arranged by Climate Central. “The scientific community is actively searching the ‘why.’ But the mechanics connecting climates and fire are quite clear. Warmer temperatures, especially in the spring, lead to early snow melt, a wider window for fuels to dry out and a longer window for ignitions to start.” “The Age of Western Wildfires” study published Tuesday reviews forest fire records of the past 42 years in 11 Western states, including Montana. It found that compared to the 1970s, there were seven times as many fires that burned at least 10,000 acres annually and five times as many that grew beyond 25,000 acres. Where the ’70s averaged fewer than 50 fires larger than 1,000 acres a year, those Western states had more than 100 on average between 2002 and 2011...more

So the scientific community is searching for the "why" behind the doubling of large fires since the 70s.

Here are two of the major reasons:  NEPA - 1969,  ESA - 1972.

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