West's wildfires expected to get bigger, fiercer
There's a dangerous but basic equation behind the killer Yarnell Hill wildfire and other blazes raging across the West this summer: More heat, more drought, more fuel and more people in the way are adding up to increasingly ferocious fires.
Scientists say a hotter planet will only increase the risk.
More than two dozen wildland fires are burning from Alaska to New Mexico, fueled by triple-digit temperatures and arid conditions. In the Arizona mountain town of Yarnell, a blaze apparently sparked by lightning killed 19 members of an elite firefighting squad who had deployed their emergency shelters Sunday when erratic monsoon winds sent flames racing in their direction.
While no single wildfire can be pinned solely on climate change, researchers say there are signs that fires are becoming bigger and more common in an increasingly hot and bone-dry West.
“Twenty years ago, I would have said this was a highly unusual, fast-moving, dangerous fire,” said fire history expert Don Falk at the University of Arizona at Tucson, referring to the Yarnell Hill fire. “Now unfortunately, it's not unusual at all.”
Wildfires are chewing through twice as many acres per year on average in the United States compared with 40 years ago, U.S. Forest Service Chief Tom Tidwell told a Senate hearing last month. Since Jan. 1, 2000, about 145,000 square miles have burned, roughly the size of New York, New England, New Jersey, Delaware and Maryland combined, according to federal records.
A draft federal report released this year said climate change is stressing Western forests, making them more vulnerable to fires.
Over the past 35 years, Arizona has seen dramatic warming, with the state's 10-year average temperature jumping from 59.1 degrees Fahrenheit in 1977 to 61.4 degrees last year — an increase of 2.3 degrees.