The giant wildfire in Alberta, Canada, rages on
Wildfires like Alberta’s are fueled by climate changeBy Carolyn Beeler
PRI's The World, May 06, 2016
This fire is an acute crisis for residents of Fort McMurray, but for the rest of the world, it’s a reminder of a larger, slower-moving phenenomen: climate change.
In the last 40 or 45 years, the area burned by wildfires in Canada has doubled, according to Mike Flannigan, a University of Alberta professor of wildland fire.
“This is the result of human-caused climate change,” Flannigan said. “We are seeing more fires on the landscape, and the fires are more intense than they used to be.”
Flannigan said warmer temperatures lead to more forest fires for three reasons:
A longer fire season
“The warmer we get, the longer our fire season is,” Flannigan said.
In Alberta, the fire season started this year on March 1, a month earlier than it used to start.
The warmer it gets, the more lightning we have. That’s because a warmer atmosphere can hold more moisture, and moisture is needed to start a lightning bolt.
The more often lightning strikes, the more frequently it can start forest fires.
As temperatures warm, the atmosphere’s ability to hold moisture increases
That means evapotranspiration, or the evaporation of water from soil and plants into the atmosphere, increases.
“It’s like the atmosphere gets more efficient at sucking the moisture out of the fuel, the stuff that burns,” Flannigan said, “so it’s easier for the fuels to catch fire and spread fire.”