Warming-fueled fires on rise

Associated Press

WASHINGTON

Alberta’s unusually early and large fire is just the latest of many gargantuan fires on an Earth that’s grown hotter with more extreme weather.

Earlier this year, large wildfires hit spots on opposite ends of the world – Tasmania and Oklahoma-Kansas. Last year, Alaska and California pushed the U.S. to a record 10 million acres burned. Massive fires hit Siberia, Mongolia and China last year and Brazil’s fire season has increased by a month over the past three decades.

It got so bad that in 2009, Australia added a bright red “catastrophic” to its fire- warning index.

“The warmer it is, the more fires we get,” said Mike Flannigan, a professor of wildland fire at the University of Alberta.

Last week, temperatures pushed past 90 degrees Fahrenheit in Alberta, which is unusual for May in northern Canada.

It’s not quite so simple, though. Many factors contribute to the complex increase in big fires, Flannigan and several experts said. They include climate change, the way people use land and firefighting methods that leave more fuel – trees and brush – to burn.

But the temperature one stands out, Flannigan said.

“The Alberta wildfires are an excellent example of what we’re seeing more and more of: warming means snow melts earlier, soils and vegetation dries out earlier, and the fire season starts earlier. It’s a train wreck,” University of Arizona climate scientist Jonathan Overpeck wrote in an email.

Worldwide, the length of Earth’s fire season increased nearly 19 percent from 1979 to 2013, according to a study by Mark Cochrane, a professor of fire ecology at South Dakota State University.

Fires had been increasing steadily, but then in the late 1990s and early 2000s, “we’ve suddenly been hit with lots of these large fires we can’t control,” Cochrane said.