Speaker: R. Daniel (Danny) Bressler

Title: The Distributional Mortality and Social Cost of Carbon

Abstract: This study assesses the distribution of climate-mortality impacts and subsequent welfare and policy implications. First, I estimate the distributional mortality cost of carbon (D-MCC)—the number of global deaths caused by emitting one tonne of CO₂ broken down by death location—using a modular spatial climate-economy integrated assessment model with mortality projections that explicitly account for the projected benefits of income growth in reducing vulnerability to heat. Deaths are overwhelmingly concentrated in hotter, poorer countries: Southern/Central Asia and Sub-Saharan Africa account for 75% of deaths in the D-MCC. Second, I estimate the social cost of carbon (SCC) across a range of social welfare functions (SWFs) with significant support in the literature. Because of climate-mortality inequality, the social cost of carbon (SCC) is highly sensitive to how the underlying SWF values lives and livelihoods. Among valuation approaches sanctioned in U.S. Federal benefit-cost analysis, SCC estimates range from $237 per 2025 tonne CO₂, (U.S. EPA’s current approach) to $3,567 (U.S. income weighting). I then apply both D-MCC and SCC estimates to the Inflation Reduction Act, which saves an estimated 2.8M lives through GHG reductions, with monetary benefits ranging from $4.7T-$68T depending on the choice of SWF. Third, I uncover the distribution of temperature-mortality impacts across demographic groups in Mexico, a country with exceptionally rich microdata that enables a deeper exploration of distributional impacts across demographic groups than the global analysis. Manual laborers exhibit more excess mortality on hot days than non-manual workers and non-workers. Half of heat-related deaths occur among manual laborers, who comprise just 9% of overall deaths. If similar occupational temperature-mortality relationships were to hold in other countries, heat-mortality adaptation may be difficult for manual laborers in developing countries with few alternative job prospects.