Projected Global Mortality and Economic Burden from Wildfire Smoke under Climate Change

Climate change is intensifying the frequency and severity of wildfires, amplifying landscape fire-sourced smoke (LFS), and its global health effects. However, future global LFS-attributable deaths and their associated attributable death costs remain poorly quantified. We projected global LFS-derived air pollution and the associated mortality and mortality-related economic burden from 2020 to 2100 under alternative climate and socioeconomic scenarios. We applied advanced deep learning algorithms trained on high-resolution, station-validated LFS data and bias-corrected climate projections to estimate daily LFS-derived fine particulate matter (PM2.5) and ozone (O3) concentrations at a 0.25° × 0.25° resolution under three Shared Socioeconomic Pathways (SSPs). These projections were combined with future population, mortality, and value-of-statistical-life (VSL) estimates and LFS-adjusted exposure–response (E–R) relationships to quantify global, regional, and national all-cause mortality attributable to LFS and the corresponding economic costs of LFS-attributable deaths. We further identified the most affected regions and evaluated how LFS exposure and sociodemographic factors shape LFS-attributable death costs across SSPs. Climate change is projected to escalate LFS pollution and its attributable mortality burden, with annual attributable death costs reaching Int \$24.4 trillion (5.52 million deaths) by 2100 under a high-emission (SSP3–7.0) scenario. In contrast, a low-emission (SSP1–2.6) pathway could reduce attributable mortality by 40.5%, preventing 2.24 million deaths annually and saving Int \$5.9 trillion by 2100. Regional disparities are expected, with some high-income regions, such as Europe, showing declines in LFS levels and associated mortality, while low- and middle-income countries are projected to remain disproportionately vulnerable to elevated LFS exposure and attributable death costs. Projected global LFS exposure is expected to increase even under a low-emission pathway, while LFS-attributable deaths and VSL-based attributable death costs vary substantially across the SSPs. These differences reflect the combined effects of changes in the LFS exposure, demographic shifts, baseline mortality, and economic development. Our findings highlight LFS-derived air pollution as an increasingly consequential health hazard and underscore the potential health and economic benefits of sustainable development, low-emission pathways, and effective climate mitigation.