The study investigates the impact of increasing atmospheric carbon dioxide (CO2) concentrations on future fire activity using seven Earth system models. The results show that a multi-model mean (MMM) increase in fire carbon emissions (fFire) of 127.7 ± 79.2% is projected compared to pre-industrial levels, with a significant increase in vegetation growth due to the CO2 fertilization effect. The MMM percent change in fFire is 66.4 ± 38.8%, with a substantial increase of 60.1 ± 46.9% attributed to enhanced vegetation growth. In contrast, the radiative impacts of CO2, such as warming and drying, yield a negligible response of fFire at 1.7 ± 9.4%. The study highlights the importance of vegetation dynamics in driving future increases in fire activity under elevated CO2 concentrations, with potential policy implications. The results also suggest that policy efforts to mitigate fire risk should consider ecological drivers and the potential counteracting effects of enhanced wildfire activity on carbon sequestration.The study investigates the impact of increasing atmospheric carbon dioxide (CO2) concentrations on future fire activity using seven Earth system models. The results show that a multi-model mean (MMM) increase in fire carbon emissions (fFire) of 127.7 ± 79.2% is projected compared to pre-industrial levels, with a significant increase in vegetation growth due to the CO2 fertilization effect. The MMM percent change in fFire is 66.4 ± 38.8%, with a substantial increase of 60.1 ± 46.9% attributed to enhanced vegetation growth. In contrast, the radiative impacts of CO2, such as warming and drying, yield a negligible response of fFire at 1.7 ± 9.4%. The study highlights the importance of vegetation dynamics in driving future increases in fire activity under elevated CO2 concentrations, with potential policy implications. The results also suggest that policy efforts to mitigate fire risk should consider ecological drivers and the potential counteracting effects of enhanced wildfire activity on carbon sequestration.