INTRODUCTION
Wildfire seasons in Canada are changing. Recent uncharacteristically large and intense wildfires have exceeded abilities for fire suppression, highlighting the urgent need for improved methods and resource
capacities to mitigate wildfire risk (Coogan et al 2019, Johnston et al 2020, Wang et al 2020). Although
the overall number of wildfire events has decreased in Canada since the 1970s, the average annual area
burned has doubled, with wildfire events exceeding 100 000 hectares in size becoming commonplace (figure 1).
In the past decade Canada has experienced numerous wildfires at the extremes of historical variability, destroying or seriously damaging human communities, wildlife habitat, and natural resources (Tymstra et al 2020, Hagmann et al 2021). This trend coincides with a steady increase in direct fire suppression costs, averaging $1 billion yr−1 since 2014—a threshold that was not predicted to occur until the latter half of the 21st century (Hope et al 2016). Direct suppression costs are only a fraction of total fire costs, and indirect wildfire costs (such as impacts to watersheds, ecosystems, infrastructure, individuals, and the local and national economies) are estimated to be two to thirty times total suppression costs (Dale 2009).
The six most impactful wildfire events in Canadian history—based on area burned, suppression costs, and the number of people evacuated—all occurred in western Canada during the last decade (figure 1, Canadian Council of Forest Ministers (2020)). These uncontainable wildfire incidents include the 2011 Slave Lake fire in northern Alberta (AB), which destroyed 500 properties with insured damages exceeding 700 million dollars (Natural Resources Canada 2020). In 2014, wildfires burned 3.5 million hectares in the Northwest Territories, the second largest area burned in a single fire season in Canada. In 2016, the Horse River fire drove 88 000
people from Fort McMurray, AB, the largest wildfire evacuation in Canadian history. At an estimated 9 billion dollars in direct and indirect damages; at the time, this fire was the costliest disaster in Canadian history (Johnston et al 2020). In 2017, British Columbia (BC) experienced its greatest annual area burned in a century (1.22 million hectares), which was quickly surpassed by another record year in 2018 (1.35 million hectares).
The 2021 wildfires in BC set several new records. The wildfire season started a month earlier than average, following three days of record setting temperatures reaching almost 50◦ C. This ‘heat dome’ catalysed a series of wildfires, including one that burned 90% of the community of Lytton, BC, resulting in the loss of two lives. The 2021 wildfire season became the third largest annual area burned in BC, with the most expensive suppression price tag of any BC wildfire season at 800 million dollars. In a disturbance cascade, these wildfires contributed to the devastating landslides and floods that inundated portions of southern BC in the fall of 2021, which have now superseded the costs of the 2016 Horse River wildfire, setting a new record for Canada’s costliest disaster. The analyses presented in this perspective focus primarily on BC, the province expected to be at highest risk of future extreme wildfire events in Canada (Jain et al 2022).
