Current food trade helps mitigate future climate change impacts in lower-income nations

RESEARCH ARTICLE Current food trade helps mitigate future climate change impacts in lower-income nations Kushank BajajID1,2*, Zia Mehrabi3, Thomas Kastner4, Jonas Ja¨ germeyr5,6,7, Christoph Mu¨ ller7, Florian Schwarzmu¨ ller4, Thomas W. Hertel8, Navin Ramankutty1,2 1 Institute for Resources, Environment and Sustainability, University of British Columbia, Vancouver, British Columbia, Canada, 2 School of Public Policy and Global Affairs, University of British Columbia, Vancouver, British Columbia, Canada, 3 Department of Environmental Studies, University of Colorado Boulder, Boulder, Colorado, United States of America, 4 Senckenberg Biodiversity and Climate Research Centre (SBiK-F), Frankfurt am Main, Germany, 5 NASA Goddard Institute for Space Studies, New York, NY, United States of America, 6 Center for Climate Systems Research, Columbia University, New York, NY, United States of America, 7 Member of the Leibniz Association, Potsdam Institute for Climate Impact Research (PIK), Potsdam, Germany, 8 Center for Global Trade Analysis, Purdue University, West Lafayette, IN, United States of America * bajajkushank@gmail.com Abstract The risk of national food supply disruptions is linked to both domestic production and food imports. But assessments of climate change risks for food systems typically focus on the impacts on domestic production, ignoring climate impacts in supplying regions. Here, we use global crop modeling data in combination with current trade flows to evaluate potential climate change impacts on national food supply, comparing impacts on domestic production

alone (domestic production impacts) to impacts considering how climate change impacts production in all source regions (consumption impact). Under 2˚C additional global mean warming over present day, our analysis highlights that climate impacts on national supply are aggravated for 53% high income and 56% upper medium income countries and miti- gated for 60% low- and 71% low-medium income countries under consumption-based impacts compared to domestic impacts alone. We find that many countries are reliant on a few mega-exporters who mediate these climate impacts. Managing the risk of climate change for national food security requires a global perspective, considering not only how national production is affected, but also how climate change affects trading partners. Introduction Climate research in food systems has mainly focused on estimating impacts on the yields of major staple crops [1, 2]. However, a country’s food supply is not solely dependent on its own production. Food systems are highly interconnected and about one-fourth of calories pro- duced are traded internationally [3]. Global agri-food trade enables low-income countries, often with lower per capita agricultural production, meet their nutritional needs [4], and PLOS ONE PLOS ONE | https://doi.org/10.1371/journal.pone.0314722 January 3, 2025 1 / 16 a1111111111 a1111111111 a1111111111 a1111111111 a1111111111 OPEN ACCESS Citation: Bajaj K, Mehrabi Z, Kastner T, Ja¨germeyr J, Mu¨ller C, Schwarzmu¨ller F, et al. (2025) Current food trade helps mitigate future climate change

impacts in lower-income nations. PLoS ONE 20(1): e0314722. https://doi.org/10.1371/journal. pone.0314722 Editor: Zakari Ali, MRC Unit The Gambia at LSHTM, GAMBIA Received: April 12, 2024 Accepted: November 14, 2024 Published: January 3, 2025 Copyright: © 2025 Bajaj et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Data Availability Statement: The national per-crop and crop-aggregated estimates for cross-border effect, production, consumption, and import impacts can be found in the Supporting Information files. Most data used in our analysis are available online. The trade data corrected for re- exports used in our analysis can be found in the open Zenodo repository (https://zenodo.org/ record/5751294#.YrXai5DMIwB). GGCMI crop productivity projections are accessible via ISIMIP. org or directly from Jonas Ja¨germeyr upon request. The food composition data used to