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Record 59,000 square miles Fires have raged across Canada this year, forcing nearly 1 in 200 Canadians to evacuate their homes and choking swathes of North America.
New research shows It is possible that some of these fires have been exacerbated by climate change. During early summer, the hot, dry, windy weather that fueled Quebec’s fires was at least twice as likely, and 20% more intense, to be caused by human-caused climate change, according to an analysis by the World Weather Attribution Group. Research organization based at Imperial College London.
Weather that increases fire risk is “getting more intense as climate change gets worse,” says Claire Barnes, a climate scientist at the Grantham Institute at Imperial College London and lead author of the study. “And they will continue to do so until we stop emitting fossil fuels.”
The study looked at human-caused climatic effects on fire weather, the conditions that make a spark likely to ignite and turn into a fire. More severe fire weather results in more serious burns, says Mike Flanigan, a fire scientist at Thompson Rivers University in British Columbia. The hotter air temperatures suck moisture from the trees and build up along the forest floor, causing them to burn with a longer, hotter flame. High winds can also cause fires to spread so quickly that it is difficult or impossible for firefighting teams to control them.
“The increase in intensity is what worries me the most,” says Flanigan. At his home in Kamloops, British Columbia, he coughs as smoky air from local fires wafts through the room. Having this increase in intensity means we’re seeing more fires that we can’t manage with direct attack.” Only About 3 of Canada’s firesAnd those cases—usually the most severe—do almost all the damage, Flanigan points out.
Fire can also do good
For all the devastation the bushfires leave in their wake, it’s important to remember that fires are an integral part of the environment of eastern Canada, says Martin Girardine, a forest ecologist with the Canadian Forest Service. region forests developed by fire And in many cases they need it to stay healthy. Scientists can look back thousands of years using climate archives, such as tree rings and fragments of ancient coal preserved at the bottom of lakes, to see that massive burns have engulfed the region’s forests at least every few hundred years. Past periods witnessed more frequent and widespread fires from modern times.
Scientists like Girardin predict that human-led climate change, combined with decades or centuries of forest management decisions that in some cases increase fire risk, will push modern fires to the brink of those historical limits.
“With climate change, we have to reach or exceed these levels,” he says.
A summer full of fire
This summer, the fires burned an area roughly the size of Florida. That’s more than double the next most devastating season, 1989. Since 1959, The area burned has doubled annually.
Fires not only burned forests, but spread to communities, an increasingly common reality as fires cover more land and people’s footprints expand, says Sandy Ernie, a fire and disaster risk expert with the Canadian Forest Service.
“Every Canadian has been affected in one way or another by the current fire season,” she says. Four firefighters have died this season. Nearly 200,000 people had to evacuate due to the fires. Millions across North America have inhaled the thick, destructive smoke.
In many of the fire areas, indigenous communities have been hardest hit. At some point in July, 75% of those ordered to evacuate were indigenous, says Dorothy Heinrichs, a disaster risk expert at the Red Cross and Red Crescent Climate Center in the Netherlands, who was involved in the study.
Fire experts have predicted for decades that climate change will drive Canada’s fires to burn more widely and more frequently. But their predictions come sooner than they thought.
“What we’re seeing this year is an indication of what we’d expect to happen maybe 20 years from now,” Girardin says.
The World Weather Attribution analysis used climate models to simulate a world free of anthropogenic climate change. The researchers compared this to weather patterns that actually occurred during 2023 — the heat and drought that gripped Canada from January onward, and the hottest May and June on record — to see how comprehensive climate change, caused primarily by the burning of fossil fuels, would be. Recreate fire weather. They found that such precarious conditions are now likely to recur approximately every 25 years.
Burns can return across the country
This summer, fires have been burning from coast to coast, creating sustained pressure that has drained Canada’s firefighting resources. This type of nationwide attack has not been common over the past 150 years or so. Before that, in the eighteenth and nineteenth centuries, fires often burned in British Columbia and Quebec, and from Manitoba to Ontario, all over the country, like this summer.
Fire activity is expected to increase more in the eastern part of the country, which is less prepared for large fires, than in the west. Previous research found.
“Eastern forests are more sensitive to moisture changes,” says Mohammad Reza Alizadeh, a climate expert at McGill University. An unprecedented hot and dry season, such as 2023, causes the region’s dense forests to burn explosively.
Normally, the wildfire season in Canada will begin to wind down soon, with the onset of fall. The weather forecast is forecasting more hot and dry weather for several weeks, which could extend the fire season well beyond its historical limits.