Enhanced future vegetation growth with elevated carbon dioxide concentrations could increase fire activity

Many regions have seen increased fire activity recently, possibly linked to warming and drying. This study investigates how rising atmospheric CO2 affects future fire activity using seven Earth system models. Around CO2 doubling, the models predict a 66.4 ± 38.8% increase in fire carbon emissions (compared to 1850 levels, with fixed 1850 land use). This increase is mainly due to enhanced vegetation growth (60.1 ± 46.9%) from CO2 biogeochemical impacts, while CO2 radiative impacts are negligible (1.7 ± 9.4%). The findings highlight the importance of vegetation dynamics in future fire activity increases under rising CO2, with significant policy implications.

Robert J. Allen, James Gomez, Larry W. Horowitz, Elena Shevliakova