New study indicates 2023 wildfire season facilitated by climate change

Aug. 23, 2024, Canada — A new study found the record-breaking 2023 wildfire season in Canada was enabled by climate change.

The study, published in Nature Communications, said, “It is inescapable that extreme heat and moisture deficits enabled the record-breaking 2023 fire season.”

The 2023 season resulted in 15 million hectares burned, breaking the previous record of 6.7 million hectares set in 1989. Over 200 communities had to be evacuated, some of them twice, the study reported.

The study cited Canada’s climate as the primary reason for the wildfire activity, saying our national climate has been warming at twice the global rate, with the mean annual temperature increasing 1.7 degrees Celsius since 1948.

In 2023, the mean national temperature during fire season was 2.2 degrees Celsius warmer than the 1991 to 2020 average.

Scientists have been predicting an increase in wildfire activity based on this steady increase in temperature, referencing the 2021 “heat dome” that covered much of northwestern North America, bringing record temperatures and an escalated wildfire season to British Columbia.

“It was estimated that the heat dome would have been 150 times less likely to occur without the ongoing anthropogenic climate disruption,” the study reported.

The study highlighted drought conditions experienced across the country due to an early snowmelt, with the country being snow free considerably earlier than the 2004 to 2022 average.

While these drought conditions are common in western Canada, 2023 saw the introduction of a “flash drought” where above-average temperatures and rapid drying quickly eliminated what started as near-average levels of soil moisture in the eastern provinces.

The flash drought was called “an emerging phenomenon that we are only beginning to understand,” by the study’s authors.

An additional consequence of the 2023 wildfire season was the widespread burning of young forests, classified in the study as forests that have existed for less than 30 years since fire or harvest.

One million hectares of young forests were affected, and the disturbance could cause extensive post-fire tree regeneration failures due to the lack of seeds provided by immature trees.

“These failures, compounded by logging legacies, drought, and insect outbreaks, could reduce forest productivity and carbon stocks, and accelerate the transition from boreal forests to open taiga, prairies or parklands,” the study reported.

The study concluded with a future outlook, outlining the required adaptations to change the trajectory of increasing wildfires caused by climate change.

“Increased focus on innovative and integrated fire management strategies that prioritize risk mitigation are gaining momentum,” the study said. “This will require all stakeholders to engage in fostering more fire resilient environments, as the 2023 fire season heralds the emergence of severe climate change impacts on fire activity decades earlier than previously anticipated.”

To read the report in its entirety, visit Nature Communications.