Wildfire activity has increased in the US and is projected to accelerate under future climate change. However, our understanding of the impacts of climate change on wildfire activity, smoke, and health outcomes remains highly uncertain, due to the difficulty of modeling the causal chain from climate to wildfire to air pollution and health. Here we quantify the mortality burden in the US due to wildfire smoke fine particulate matter (PM2.5) under climate change. We construct an ensemble of statistical and machine learning models that link climate to wildfire smoke PM2.5, and empirically estimate smoke PM2.5-mortality relationships using data on all recorded deaths in the US. We project that smoke PM2.5 could result in 71,420 excess deaths (95% CI: 34,930 - 98,430) per year by 2050 under a high warming scenario (SSP3-7.0) – a 73% increase relative to estimated 2011-34 2020 average annual excess deaths from smoke. Cumulative excess deaths from smoke PM2.5 could reach 1.9 million between 2026-2055. We find evidence for mortality impacts of smoke PM2.5 that last up to three years after exposure. When monetized, climate-driven smoke deaths result in economic damages that exceed existing estimates of climate-driven damages from all other causes combined in the US. Our research suggests that the health impacts of climate-driven wildfire smoke could be among the most important and costly consequences of a warming climate in the US.
Published Sep 18, 2025
Qiu, M., Li, J., Gould, C. F., Jing, R., Kelp, M., Childs, M. L., Wen, J., Xie, Y., Lin, M., Kiang, M. v., Heft-Neal, S., Diffenbaugh, N. S., & Burke, M. (2025). Wildfire smoke exposure and mortality burden in the US under climate change. Nature 2025, 1–3. https://doi.org/10.1038/s41586-025-09611-w