Exposure of the Canadian wildland–human interface and population to wildland fire, under current and future climate conditions

Abstract

In Canada, recent fire seasons have demonstrated the threat of wildland fire in the wildland–human interface (WHI) areas, where forest fuels intermingle with or abut housing, industry, and infrastructure. Although fire activity is expected to increase further in the coming decades as a result of climate change, no WHI-specific estimates of wildland fire exposure are currently available. This study combines spatial and demographic information sources to estimate the current and future wildland fire exposures, as reflected by fire return intervals (FRI) of WHI areas and populations across Canada. The WHI covers 17.3% of the forested area in Canada. Within the WHI, we found that 19.4% of the area currently experiences FRI of ≤250 years, but by the end of the century, this could increase to 28.8% under Representative Concentration Pathway (RCP) 2.6 and to 43.3% under RCP 8.5. Approximately 12.3% of the Canadian population currently live in the wildland–urban interface (WUI), which includes 32.1% of the on-reserve First Nations population. Currently, 17.8% of the on-reserve WUI population is exposed to FRI of ≤250 years, compared with only 4.7% of the remaining WUI population. By 2100, these proportions could reach 39.3% and 17.4%, respectively, under the less optimistic climatic scenarios (RCP 8.5).