Weather conditions fed The wildfires that broke records in eastern Canada earlier this summer — and sent plumes of dangerous air into the United States — are becoming more likely and more severe because of the climate crisis, according to a new report. New report Posted Tuesday.
scientists from Global weather attribution The initiative — which calculates the role of climate change in extreme weather events — found that human-caused climate change more than doubles the likelihood of the hot, dry, windy conditions that led to the Quebec fires. Between May and July, this weather made the fire-prone at least 20% more intense.
According to the report, the severity of the fire season in Quebec through the end of July has become 50% more severe due to climate change.
Frederic Otto, co-founder of WWA and senior lecturer at the UK’s Grantham Institute, said the impact of climate change could be much larger than the study’s figures show, adding that the report used the most conservative estimates.
Wildfires are difficult to study because of the intertwined factors that affect them, but scientists say climate change, driven by the burning of fossil fuels, is betting on more destructive fires.
“It is becoming clear that the dry, warm conditions that lead to wildfires are becoming more common and more intense around the world as a result of climate change,” said Claire Barnes, research associate at the Grantham Institute and author of the report.
Canada experienced an unprecedented fire season this year, amid hot and dry conditions. May-June was Canada’s warmest two months since records began in 1940, breaking the previous record by a large margin – 0.8°C (1.4°F).
More than 15 million hectares (more than 37 million acres) have burned across the country – an area the size of Illinois. The fires have killed at least 17 people and forced the evacuation of more than 150,000.
Quebec was particularly affected, with the largest area burned of any Canadian province. Bushfires have destroyed 5.2 million hectares (12.8 million acres) there so far, about 26 times the average area burned by late August.
The fires have also caused dangerous levels of air pollution in and across Canada swathes of the United States, leading to school closures in both countries and an increase in asthma-related hospital visits. Smoke from even fires reached Western Europe.
It is by far the worst wildfire season Canada has ever seen, and we are still over two months away.
To understand the role of climate change in fires, WWA scientists looked at “fire weather” — including high temperatures, strong winds and dry conditions, all factors that help fires burn, spread and intensify.
The scientists used data from the Fire Weather Index — a measure of fire risk — to gauge the persistence of severe fire conditions as well as the overall severity of the fire season. Then they used climate models to understand the role climate change has played.
They concluded that an intense wildfire season like the one Quebec experienced through the end of July was at least seven times more likely to occur due to climate change, and that human-caused warming made Quebec’s total fire season at least 50% more likely. Intense.
Climate change also made the peak fires in Quebec during the same period at least twice as likely and 20% more intense, according to the report.
While the Quebec fires were unprecedented, the report’s authors wrote, “they are no longer so unusual.”
The report found that in today’s climate, which is about 1.2 degrees Celsius warmer than in pre-industrial times, similar weather conditions can be expected every 25 years.
There are still about 1,000 fires burning across Canada, 200 of which are burning in the Northwest Territories, where thousands of people were evacuated Friday from the capital, Yellowknife. About 35,000 people are under evacuation orders in British Columbia.
There are many factors that contribute to severe wildfire seasons, including logging, large-scale deforestation and local fire abandonment, said Kira Hoffman, a fire ecologist at the University of British Columbia and Bulkley Valley Research Center, who was not involved in the report. . supervision techniques.
But all of these factors Interaction with the climate crisisshe told CNN. “The rapidly changing climate is leading to longer, drier, and hotter wildfire seasons across Canada,” Hoffman said.
One of the main concerns about increased fire behavior is the impact on wildfire management, said Michael Flanigan, research chair of predictive services, emergency management and fire sciences at Thompson Rivers University.
“If we see more days above the fire intensity thresholds, we will see more runaway fires, more burned areas, and more community impacts,” he told CNN.
“Until we stop burning fossil fuels, the number of wildfires will continue to increase, burning larger areas for longer periods of time,” Otto said in a statement.