Climate change made high temperatures ahead of the Jasper wildfire twice as likely and—combined with decades of fire-suppression management—led to blaze that has not stopped burning since July 22.
“Prolonged periods of exceptionally high temperatures, like those we saw in the weeks preceding the Jasper fire, are becoming more likely due to climate change,” said Kaitlyn Trudeau, senior research associate for Climate Central, which released data to back up the analysis.
Higher temperatures are linked to dry forest conditions that make fires more likely and intense.
“While these hot and dry conditions don’t ignite fires themselves, they act as a threat multiplier, increasing the risk of more extreme fire behaviour,” Trudeau said.
Climate Central turned to its Climate Shift Index (CSI), which uses a scale of -5 to +5 to indicate how strongly temperatures can be linked to climate change, to examine temperatures around the time the fire started. The Jasper area scored a CSI level of at least 2, meaning that high temperatures from July 15 to 23 were at least twice as likely to have happened because of the influence of climate change.
On the day the fire started, July 22, temperatures were 7.1° to 10.3°C higher across Jasper than averages recorded between 1991 and 2020.
In 2023, peer-reviewed research published in the journal Nature found that lightning strikes, which may have been responsible for starting the Jasper fire, are 11% to 31% more likely for every degree of global warming.
Climate Central’s findings align with other reports about climate change’s links to high temperatures. In a recent report based on its Rapid Extreme Weather Event Attribution system, Environment and Climate Change Canada recently concluded that summer heatwaves across the country were at least two to 10 times more likely because of human influence on the climate.
High temperatures were not the only issue at play in Jasper. Decades of forest management that suppressed fires around Jasper National Park and in other areas like it have allowed forest litter to accumulate, supplying ample fuel when the fires sparked in late July.
While the value of prescribed burning methods—such as those long practiced by Indigenous peoples before colonization by Europeans—is now better understood, the transition away from fire suppression strategies is proving to be difficult.
Some conservation experts and park officials say prescribed burning to offset the intensity of future fires will be impossible in some areas, where burns could threaten homes or wildlife. For example, limited available habitat for caribou in Alberta means conserved areas cannot be burned deliberately, as there would be nowhere else for the caribou to go during that time.
“I think one of the difficulties in the current landscape, with the amount of industrial disturbance through forestry and mining and everything, is that you can’t manage a protected area on its own,” Wesley Bell, a conservation policy specialist with the Canadian Parks and Wilderness Society, told The Narwhal.
“It needs to be within the broader landscape. And that’s particularly challenging with the extent of the disturbance that there is in Canada, but in Alberta especially.”
