# Economic Impacts of Climate Change in the United States: Integrating and Harmonizing Evidence from Recent Studies

## TL;DR

This paper synthesizes U.S.-focused climate change impact studies, harmonizing economic and climate data to refine estimates of future GDP losses and social costs of greenhouse gases, emphasizing the need for integrated research on market and nonmarket damages.

## Contribution

It develops an apples-to-apples comparison of econometric studies and integrates nonmarket damages to refine estimates of climate change impacts and social costs in the U.S.

## Key findings

- Harmonized models project narrower, lower GDP loss ranges by 2100.
- Implied social cost of greenhouse gases exceeds current market-based estimates.
- Integration of nonmarket damages increases the estimated social cost of GHGs.

## 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.