Climate Change is Making Wildfires in Canada Bigger, Hotter and More Dangerous

On May 30, the morning that Alberta’s Premier Jason Kenney planned a news conference to take credit for repealing the provincial carbon tax he inherited from the NDP, Edmontonians woke up to discover their city covered in a thick yellow blanket of foul-smelling smoke.

By the end of the day, Environment Canada had issued air-quality alerts for most of the province. In Edmonton, the air measured 10-plus on a scale of one to 10, meaning it posed a “very high” health risk.

Kenney cancelled his carbon tax news conference to be briefed on the out-of-control wildfires turning tens of thousands of hectares of spruce, pine and aspen into ash. The most dangerous fire, and the source of much of the smoke, was the Chuckegg Creek fire—a 100,000-hectare monster threatening the town of High Level, 400 km west of Fort McMurray.

When Kenney next talked to reporters, after a speech in Calgary the following day, he confidently brushed aside questions about the irony of cancelling a carbon tax announcement because of fires that scientists link to climate change.

“The carbon tax didn’t stop forest fires in British Columbia or in Alberta,” Kenney said. “We’ve always had forest fires here. We always will. There’s complex factors here, one of which is, there’s huge patches of very old boreal forests where there have not been fires for, in some cases, 80 or 90 years. So all of the forestry experts will tell you these forests have been overdue for a major forest fire.”

The forestry experts will also tell you that forest fires—in Australia, California, British Columbia and Alberta—are bigger, hotter and more dangerous than fires in the past because of climate change, and we had better get used to them. This is the new reality, and there is reason to worry it will get worse and worse.

So far this summer, fires in northern Alberta have burned more than 800,000 hectares, an area bigger than Prince Edward Island. Unless Alberta gets a lot of rain soon, before the snow flies, the province will beat the record set in 1981, when 1.3 million hectares burned.

It looks like this will be a fiery summer, and not just in Alberta. As of early July, there were big out-of-control fires burning in unusually dry northwestern Ontario, and British Columbia’s fire season lies ahead.

These fires are different from forest fires in the past. They are often burning too hot, too fast and too big for firefighters to do much but stay out of their way.

There is too much fuel for them, not, as Kenney said, just because it has been too long between fires, but because it has been unusually dry for years, so that the top layer of the forest floor—which you would think of as dirt if you were walking on it—is catching fire.

That’s making the fires hotter and more dangerous, especially when they produce pyrocumulonimbus clouds—towering cauliflower-shaped columns of smoke that morph into fiery thunderstorms, generating unpredictable tornado-strength winds that accelerate the fire at ground level, tossing burning trees around like twigs. Often, these hellish firestorms generate dry lightning, which sparks new fires downwind from the main fire.

On May 29, there were three pyrocumulonimbus storms in northern Alberta, fire-breathing monsters sending plumes of smoke up into the stratosphere, more than 10 km above the burning treetops. The smoke from these storms goes so high that, like the particles from volcanic eruptions, it can end up circling the world.

Mike Fromm, a scientist at the U.S. Naval Research Laboratory in Washington D.C. who tracks pyrocumulonimbus storms using satellite imagery from NASA, watched with interest this year as Alberta went off the charts. “In the past, in the span of May to June, you might get one to three on average,” he says. “This year we’ve had 10.”

Fromm tracked the smoke from one fire 300 km north of Edmonton as it moved east across Saskatchewan and Manitoba and eventually across Europe and Asia.

These monster fires are a challenge for Alberta, forcing officials to call for help from across Canada and around the world. Firefighters from as far away as Mexico and South Africa are staying at makeshift tent cities across northern Alberta, taking breaks between gruelling shifts putting out embers, cutting firebreaks and doing controlled burns, while choppers and water bombers fight the fire from the air.

In mid-May, when the wind was blowing away from High Level, firefighters were able to use heavy equipment to cut firebreaks, and burned about 6,000 hectares of trees so that there was no fuel between the fire and the town. Firefighters in trucks patrolled the evacuated town putting out burning embers, which can travel long distances through the air.

David Finn, Alberta’s fire behaviour specialist, watched nervously as the Chuckegg Creek fire went on long runs—spreading as far as 30 km in one memorable day.

“We had conditions in May that were so dry that the fire burned overnight,” he says. “Normally, fires will lay down, or go to sleep. Of course, they’re still burning, but the rapid rate of spread, the crown fire, the really dramatic fire that you see, that stops in the overnight hours as the humidity increases and the temperature drops. During the month of May, the air mass was so dry that didn’t happen. The fire burned with full intensity all night long.”

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