Canadian wildfire in a changing climate from the 2023 wildfire season to the 2100s

Wildfire influences the carbon cycle and impacts property, harvestable timber, and public health. The year 2023 saw a record area burned of 14.9 Mha in Canada, compared to an average of ~2 Mha between 1959 and 2015. Boreal wildfire is a critical process that is difficult to represent in land surface models. To enhance our understanding of historical and future wildfire regimes in Canada and their impact on carbon cycling we implement two methods of representing boreal wildfire in the Canadian Land Surface Scheme Including Biogeochemical Cycles (CLASSIC). These include a new dynamic wildfire model that represents fire weather and lightning ignitions as well as a fire model which is forced by historical observations of burned area. We find that in 2023 simulated wildfire emissions were eight times their 1985 - 2022 mean with consequences for the annual net carbon balance in Canada. Moving into the future we find that climate change below a 2°C global target (shared socioeconomic pathway [SSP] 126) yields burned area near modern (2004 - 2014) norms by end-century (2090 - 2100). However, under rapid climate change (SSP370/585), the end-century mean annual burned area increases 2 - 4 times, compared to present-day values, approaching the burned area seen in Canada in 2023. This work illustrates the historical implications of Canadian wildfires on the carbon cycle and the future implications of climate change for area burned in Canada.