The changing risk and burden of wildfire in the United States

TLDR

Recent dramatic and deadly increases in global wildfire activity have heightened attention on wildfire causes, consequences, and mitigation strategies. This study compiles data on the changing risk and societal burden of wildfire in the United States. We estimate that nearly 50 million homes lie in the wildland–urban interface, growing by about one million every three years, and develop a statistical model linking satellite fire and smoke data to air‑quality monitoring stations to assess impacts. The model indicates that wildfires contributed up to 25 % of PM₂.₅ nationwide and up to 50 % in some western regions, with exposure patterns decoupled from socioeconomic gradients; scenario analyses suggest fuel‑management could yield substantial health benefits, while climate‑driven increases in smoke could rival projected temperature‑related mortality, though uncertainties remain, highlighting priority research and policy lessons.

Abstract

Recent dramatic and deadly increases in global wildfire activity have increased attention on the causes of wildfires, their consequences, and how risk from wildfire might be mitigated. Here we bring together data on the changing risk and societal burden of wildfire in the United States. We estimate that nearly 50 million homes are currently in the wildland–urban interface in the United States, a number increasing by 1 million houses every 3 y. To illustrate how changes in wildfire activity might affect air pollution and related health outcomes, and how these linkages might guide future science and policy, we develop a statistical model that relates satellite-based fire and smoke data to information from pollution monitoring stations. Using the model, we estimate that wildfires have accounted for up to 25% of PM 2.5 (particulate matter with diameter <2.5 μm) in recent years across the United States, and up to half in some Western regions, with spatial patterns in ambient smoke exposure that do not follow traditional socioeconomic pollution exposure gradients. We combine the model with stylized scenarios to show that fuel management interventions could have large health benefits and that future health impacts from climate-change–induced wildfire smoke could approach projected overall increases in temperature-related mortality from climate change—but that both estimates remain uncertain. We use model results to highlight important areas for future research and to draw lessons for policy.