Valuing wildfire smoke-related mortality benefits from climate mitigation

Area of Science:

• Environmental Science
• Public Health
• Climate Science

Background:

• Human-induced climate change exacerbates wildfire risks and associated air pollution.
• Climate-induced wildfire smoke impacts are often excluded from societal cost estimations.
• Fine particulate matter (PM2.5) from smoke poses significant health risks.

Purpose of the Study:

• To develop a framework estimating air pollution and mortality from climate-induced wildfire smoke in the US.
• To quantify the health damages under different greenhouse gas emission and temperature scenarios.
• To integrate wildfire smoke damages into the social cost of carbon calculations.

Main Methods:

• Developed an integrated framework to model PM2.5 exposure from wildfire smoke.
• Empirically estimated fire-vegetation feedbacks to predict future burn probability.
• Calculated mortality damage and monetized damages (social cost of carbon) under various warming scenarios.

Main Results:

• Under 3°C warming, annual US deaths from smoke exposure are estimated at 64,000 (a 60% increase).
• Limiting warming to 2°C reduces annual smoke-related mortality by 14% (8,900 deaths).
• Each additional tonne of CO2 in 2025 incurs an $11.2 monetized damage from US wildfire smoke mortality.

Conclusions:

• Wildfire smoke damages substantially increase the US social cost of carbon by 74%.
• Greenhouse gas mitigation offers significant economic benefits by reducing climate-induced wildfire smoke mortality.
• Incorporating wildfire smoke into climate damage assessments is crucial for accurate policy evaluation.