EDMONTON — Alberta’s intense 2023 wildfire season “redefined what is possible under a warming climate”, warns Jen Beverly, a professor of wildland fire in the University of Alberta’s Faculty of Agricultural, Life & Environmental Sciences, and co-author of a new perspective paper, published in the Canadian Journal of Forest Research. The paper analyzed operational fire data to learn why the season far exceeded all other years in the province’s historical record dating back a century.
The wildfire season was fueled by an unusual mix of blazes caused first by unexpected early lightning strikes, igniting a staggering outbreak of large wildfires, followed by regular additions of new large fires through to September. Both of these fire patterns — which normally wouldn’t occur together in a single year — fed 36 large fires that devoured an estimated 2.1 million hectares of land, according to the study. That’s about 63 per cent greater than the previously recorded maximum in 1981.
Though the combination appears to be an anomaly, Beverly says the events exposed the new threat of early lightning strikes. The wildfire season started with an early season outbreak of 18 blazes in the first two weeks of May. Of those, 13 were caused by lightning strikes — an unusually high number for early May.
“Normally lightning doesn’t start to become a factor in spring wildfires until late May, and more into June, July and August,” Beverly explains, noting the historical average is just one such fire in the same time period per decade between 1983 and 2022.
“If we hadn’t had that outbreak in early May from lightning fires, the season would still have been severe but it would not have been off the charts.”
While large wildfires in Alberta were, on an individual basis, similar in size and intensity to past years, there were simply more of them, the report notes. In the 25 years prior to 2023, there was an average of two fires per year larger than 10,000 hectares, compared with the all-time high of 36 comparable blazes that burned last year.
The observations in the paper show the need for more extensive research to explore what future fire seasons could bring in the face of climate warming, Beverly suggests.
“The study opens up a lot of questions. We need to better understand weather patterns and what is happening with that warm weather and lightning activity in the month of May,” she adds. “We may not see another burst of early lightning activity for 30 more years, but what 2023 shows us is that we are extremely vulnerable.”
More information can be found here. To speak with Jen Beverly, please contact: Sarah Vernon | University of Alberta communications associate | svernon@ualberta.ca