Canadian forests primed for more severe wildfire days, new research warns

Canadian forests are facing an increasing threat of severe, uncontrollable wildfires, according to a recent study published in the peer-reviewed journal Science. The study, conducted by Canadian researchers, analyzed fire severity in Canadian forests from 1981 to 2020, highlighting the urgent need to address the escalating risk posed by climate change.

The research revealed a concerning trend of rising high-burn severity days across Canada, indicating a more challenging fire season under the changing climate. Co-author Xianli Wang, a research scientist with the Canadian Forest Service, noted that there were, on average, two additional days conducive to high-severity fires in the years 2000 to 2020 compared to the previous two decades. In some regions, this number increased to as much as five days.

The impact of these changes was starkly evident in last summer’s devastating wildfire in Jasper, Alberta, which rapidly spread to approximately 60 square kilometers in a matter of hours. Wang described this as a “more dramatic fire situation” than in previous years, offering a glimpse into the future of wildfire risks in Canada.

The study emphasized the critical role of dry fuel, such as twigs and leaves, in fueling severe wildfires, with weather conditions like hot, dry, and windy weather amplifying the risk in northern regions. Drought was identified as a key driver of fire severity, underscoring the importance of addressing climate change-induced environmental stressors.

As the fire season lengthens due to climate change, the study highlighted increases in high-severity burn days during spring and autumn, coinciding with the most severe summer months. This shift challenges the conventional understanding that only summer fires are severe, with spring fires now posing a significant threat to forest ecosystems.

The regions experiencing the greatest increase in burn severity days were northern Quebec and parts of Northwest Territories, northwest Alberta, and northeast British Columbia, all of which are characterized by extensive coniferous forests. In contrast, areas with fewer low-burn severity days were predominantly found in southern broadleaf and mixed-wood forests.

Severity of wildfires can have lasting impacts on forest recovery, with severe fires potentially destroying seeds stored in the soil and hindering natural regeneration. The study recommended using the findings to inform strategic decisions around prescribed burns, which can help support natural regeneration and reduce fire hazards to nearby communities.

Overall, the study serves as a stark reminder of the escalating threat of wildfires in Canadian forests and the urgent need to prioritize proactive measures to mitigate the risks posed by climate change. By leveraging scientific insights and strategic planning, stakeholders can work towards safeguarding forest ecosystems and communities against the growing threat of uncontrollable wildfires.