Scientists have found that the climate crisis has doubled the likelihood of wildfires in Canada | Forest fires

Scientists have discovered that the conditions that triggered this year’s wave of severe wildfires in Canada, blanketing parts of the US and Canada in toxic smoke, were at least twice as likely to be caused by the human-caused climate crisis.

The 2023 Canadian wildfire season was the largest and most destructive on record, with nearly 14 million hectares (34 million acres) burned, an area larger than Greece. More than twice the size of the previous record, the fires killed more than a dozen people, evacuated thousands, sent a column of smoke that reached Norway and upended the sky for a time in June. Over orange New York City.

Scientists have now analyzed the conditions that caused the fires that raged in the Canadian province of Quebec between May and July, and found that the climate crisis, triggered by the burning of fossil fuels, made them at least twice as likely, and weather-prone fires at least 20 percent more intense.

attribution study, Conducted by a coalition of scientists in Canada, the United Kingdom and the NetherlandsIt found that while the atmospheric conditions prone to fires were unprecedented, they were no longer unpredictable and would become more common as the world continued to warm.

“The word ‘unprecedented’ does not do justice to the intensity of wildfires in Canada this year,” said Jan Boulanger, a research scientist with Natural Resources Canada and part of the World Weather Attribution study team.

“From a scientific perspective, doubling the previous record for burned areas is shocking. Climate change is dramatically increasing the flammability of the fuel available for wildfires – meaning that a single spark, no matter where it comes from, can quickly turn into a blazing inferno.

The new study looked at the Fire Weather Index, a measure that measures wildfire risk through a combination of temperature, wind speed, humidity and precipitation, and found that it peaks in Quebec from May to July, when there are a high number of fires. The chances of its occurrence have multiplied due to the climate crisis. Fires at this peak were also 20% more intense due to the climate crisis.

While climate change in and of itself does not usually start huge wildfires, it helps pave the way for them by drying out plants that become easy fuel for the fires. The early stages of summer were ideal conditions for this, breaking Canada’s national temperature record for May and June by 0.8 °C (1.4 °F), which, along with low humidity and shrinking snow cover, helped the rapid spread of fires throughout Canada. .

Snow cover has traditionally limited the extent of wildfires in Canada, but that is changing, said Philippe Gashon, a researcher at the University of Quebec in Montreal.

“This year, high temperatures led to rapid thawing and disappearance of snow during the month of May, particularly in eastern Quebec, which led to unusually early wildfires,” he said. “The continued loss of snow in a warm climate means wildfires will continue for several more days each year in Canada.”

The fires had far-reaching consequences as smoke enveloped Canadian cities, including Toronto and Ottawa, before traveling south to engulf parts of the United States. New York temporarily experienced the worst air quality in the world due to the smoke, prompting people to stay indoors and wear masks that have not been worn since the height of the Covid pandemic.

Scientists were previously reluctant to link any single event or events to the climate crisis, but the emerging field of attribution has enabled researchers to draw stronger and faster conclusions about the impact of global warming on extreme weather. Recent studies have shown that the heat waves that hit the United States, Europe and China this year would have been almost impossible had it not been for the conditions caused by the climate crisis.

“Rising temperatures are creating wildfire-like conditions in forests in Canada and around the world,” said Frederic Otto, a climate scientist at Imperial College London.

“Until we stop burning fossil fuels, the number of wildfires will continue to increase, burning larger areas for longer periods of time.”