Global wildfire patterns and drivers under climate change

Abstract. Wildfires increasingly threaten human lives, ecosystems, and climate, yet a comprehensive understanding of the factors driving their future dynamics and emissions remains elusive, hampering mitigation efforts. In this study, we assessed how future climate change would influence global burned area (BA) and carbon emissions between 2015 to 2100 using the Community Land Model version 5 (CLM5) with active biogeochemistry and fires. The model reasonably captures observed spatial and seasonal patterns of BA and emissions during the present-day reference period. Under two future scenarios – SSP1-2.6 (low warming) and SSP3-7.0 (high warming) – CLM5 projects global BA increases of +6400 and +7500 km2 yr−1, respectively. Northern extratropics, particularly the boreal regions, emerge as the dominant hotspot with BA increasing by 200 % and fire-related carbon emissions by +4 to +7 Tg yr−1, while in tropical regions BA remains comparatively stable or slightly declines. These shifts are associated with warming-induced changes in vegetation productivity and fuel dryness, particularly in boreal ecosystems. Enhanced vegetation carbon contributes to fuel availability, while declines in relative humidity and soil moisture increase flammability. Elevated atmospheric CO2 also contributes to these effects by enhancing biomass growth through fertilization and increasing water use efficiency, thereby affecting fire risks and carbon emissions. These findings underscore the need to integrate climate-vegetation-fire interactions into global policy frameworks for effective mitigation and adaptation planning of future fire-related threats.