The 2023 Canadian forest fires were exceptionally severe, with carbon emissions from May to September 2023 estimated at 647 TgC (570–727 TgC), comparable to the annual fossil fuel emissions of large nations like India, China, and the USA. The fires were driven by widespread hot and dry weather conditions, which were the warmest and driest since at least 1980. These conditions are expected to become typical by the 2050s under moderate climate mitigation scenarios, indicating a potential increase in fire activity and suppression of carbon uptake by Canadian forests. The study uses inverse modeling of satellite carbon monoxide observations to quantify the emissions and examines the impact of climate anomalies and future projections on fire activity. The findings highlight the significant role of Canadian forests in carbon sequestration and the potential long-term durability of these forests as a carbon sink, which is crucial for meeting climate targets.The 2023 Canadian forest fires were exceptionally severe, with carbon emissions from May to September 2023 estimated at 647 TgC (570–727 TgC), comparable to the annual fossil fuel emissions of large nations like India, China, and the USA. The fires were driven by widespread hot and dry weather conditions, which were the warmest and driest since at least 1980. These conditions are expected to become typical by the 2050s under moderate climate mitigation scenarios, indicating a potential increase in fire activity and suppression of carbon uptake by Canadian forests. The study uses inverse modeling of satellite carbon monoxide observations to quantify the emissions and examines the impact of climate anomalies and future projections on fire activity. The findings highlight the significant role of Canadian forests in carbon sequestration and the potential long-term durability of these forests as a carbon sink, which is crucial for meeting climate targets.