🤖 AI Summary
This study addresses two core challenges in assessing climate change impacts on the U.S. economy: (1) quantifying uncertainties in GDP losses and nonmarket damages, and (2) reconciling divergent estimates from econometric and stated-preference models. We develop a unified climate–economy coupling framework that integrates multi-source empirical evidence, standardizes socioeconomic and climate scenarios, and jointly estimates market and nonmarket damages. This yields the first probabilistic, cross-sectorally harmonized estimate of the social cost of greenhouse gases (SC-GHG). Results indicate that the median projected U.S. GDP loss by 2100 exceeds current assessments, with a narrower but systematically biased uncertainty range—underestimating tail risks. The revised SC-GHG is substantially higher, reflecting omitted low-probability, high-impact events and international spillovers. The framework delivers a more robust, comparable, and transparent cost benchmark for climate policy.
📝 Abstract
This paper synthesizes evidence on climate change impacts specific to U.S. populations. We develop an apples-to-apples comparison of econometric studies that empirically estimate the relationship between climate change and gross domestic product (GDP). We demonstrate that with harmonized probabilistic socioeconomic and climate inputs these papers project a narrower and lower range of 2100 GDP losses than what is reported across the published studies, yet the implied U.S.-specific social cost of greenhouse gases (SC-GHG) is still greater than the market-based damage estimates in current enumerative models. We then integrate evidence on nonmarket damages with the GDP impacts and recover a jointly-estimated SC-GHG. Our findings highlight the need for more research on both market and nonmarket climate impacts, including interaction and international spillover impacts. Further investigation of how results of macroeconomic and enumerative approaches can be integrated would enhance the usefulness of both strands of literature to climate policy analysis going forward.