Wildfires in Canada and Alaska drive thousands from homes

"Extreme." "Unprecedented." "Historic." Those are just a few of the words being used to describe the start of this year's fire season in North America.

The wildfires are centered in the northwest of the continent, but their consequences are far-reaching. Thick smoke has blanketed parts of Wisconsin and North Dakota. It's triggered air alerts in Minnesota and Montana and muddied skies as far south as Tennessee and Colorado.

And, of course, things are even worse at the source.

In Canada thousands of people have been evacuated from their homes because of air quality and actual flames, as the country deals with an unusually devastating start to its fire season.

Thousands of wildfires have been burning in the conifers and spruce of Canada's boreal forests — some big, some small, most in rural, hard-to-reach places.

In British Columbia, many of the fires are only being monitored, seen from above by aircraft or with satellite imagery, which shows about half of the province covered in white smoke.

In Saskatchewan, the fires are more threatening. They're growing into each other and combining as fire crews and aircraft work through the thick clouds of smoke that have forced more than 10,000 people to evacuate.

In total, more than 10,000 square miles — roughly the size of Massachusetts — have burned in Canada.

"The situation is Canada is extreme right now, specifically in Western Canada," says Kerry Anderson, research scientist with the Canadian Forest Service. "Western Canada has seen about three times the area that's normally burned for this time of year."

The fires have stretched firefighting resources thin.

"Pretty much all of the resources in Canada are tapped out," Anderson says. "They're all on the fireline, and now we're bringing in resources internationally, from Mexico, Australia, New Zealand."

The forest service has made more recent requests for help to South Africa, France and the U.S.

The Canadian government has even scrambled its armed forces to help, putting several battalions' worth of soldiers through a crash course on fire suppression and sending them out to the fireline.

"That's what we have to do in these sorts of situations," Anderson says.

Fires are not just afflicting Canada. Alaska's fire season is off to a historic start as well. Record high temperatures in much of the state, combined with a three-day lightning storm, sparked more than 300 fires late last month. Those have since grown to burn more than 3 million acres.

"There's an awful lot of landscape in Alaska, and a good portion of it is experiencing wildland fires right now," says Sam Harrel of the Bureau of Land Management's Alaska Fire Service.

Some weather and climate scientists are blaming the increase in fire activity on the developing El Niño weather pattern, saying it caused a dry winter and a hot spring.

Mike Flanagan, professor of wildland fire at the University of Alberta, says it's bigger than that. If you look at Canada's fire numbers, Flanagan says, "Our area burned has doubled since the early '70s, using a running average of 10 years."

That's despite improvements in firefighting technology and resources.

This year isn't a one-off because of El Niño, he says, but part of a larger trend driven by human-caused climate change.

Even if the fires slow in the coming weeks, as is expected, lingering burns could be a problem in the far north, he says.

"With the deep organic materials that you'll find in Alaska and boreal Canada, it's not unheard of for fires to burn meters deep and survive winters, and then pop up the next spring," Flanagan says.

In other words, he says, some of the fires that are burning now may still be burning this time next year. Copyright 2019 NPR. To see more, visit https://www.npr.org.