Agriculture, bioenergy, and water implications of constrained cereal trade and climate change impacts

RESEARCH ARTICLE Agriculture, bioenergy, and water implications of constrained cereal trade and climate change impacts Ying ZhangID*, Stephanie Waldhoff, Marshall Wise, Jae Edmonds, Pralit Patel Joint Global Change Research Institute, Pacific Northwest National Laboratory, College Park, Maryland, United States of America * ying.zhang@pnnl.gov Abstract International trade increases connections and dependencies between countries, weaving a network of global supply chains. Agricultural commodity trade has implications for crop pro- ducers, consumers, crop prices, water and land uses, and other human systems. Intercon- nections among these systems are not always easy to observe when external impacts penetrate across multiple sectors. To better understand the interactions of non-linear and globally coupled agricultural-bioenergy-water systems under the broader economy, we introduce systematic perturbations in two dimensions, one human (restrictions on agricul- tural trade) and the other physical (climate impacts on crop yields). We explore these inde- pendently and in combination to distinguish the consequences of individual perturbation and interactive effects in long-term projections. We show that most regions experience larger changes in cereal consumption due to cereal import dependency constraints than due to the impacts of climate change on agricultural yields. In the scenario where all regions ensure an import dependency ratio of zero, the global trade of cereals decreases ~50% in 2050 com-

pared to the baseline, with smaller decreases in cereal production and consumption (4%). The changes in trade also impact water and bioenergy: global irrigation water consumption increases 3% and corn ethanol production decreases 7% in 2050. Climate change results in rising domestic prices and declining consumption of cereal crops in general, while the import dependency constraint exacerbates the situation in regions which import more cereals in the baseline. The individual and interactive effects of trade perturbations and climate change vary greatly across regions, which are also affected by the regional ability to increase agricultural production through intensification or extensification. 1 Introduction International trade and global supply chains create strong connections across regions. Trade in agricultural commodities impacts crop producers, consumers, crop prices, water and land uses, as well as other human systems. The potentially far-reaching implications of the com- bined effects of climate change impacts on crop yields and human decision-making have many interactions and feedbacks that can be difficult to disentangle, because all that is observed is the final consequence of the coupled systems. PLOS ONE PLOS ONE | https://doi.org/10.1371/journal.pone.0291577 September 15, 2023 1 / 18 a1111111111 a1111111111 a1111111111 a1111111111 a1111111111 OPEN ACCESS Citation: Zhang Y, Waldhoff S, Wise M, Edmonds J, Patel P (2023) Agriculture, bioenergy, and water implications of constrained cereal trade and climate change impacts. PLoS ONE 18(9): e0291577.

https://doi.org/10.1371/journal.pone.0291577 Editor: Muhammad Khalid Bashir, University of Agriculture Faisalabad, PAKISTAN Received: March 13, 2023 Accepted: September 1, 2023 Published: September 15, 2023 Copyright: © 2023 Zhang 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: Both the data and code needed to reproduce the research and figures presented in this publication are fully accessible in this public repository: https://github.com/ yingzhangpnnl/agtrade-climate-msd-paper. Funding: This research was supported by the U.S. Department of Energy, Office of Science, as part of research in MultiSector Dynamics, Earth and Environmental System Modeling Program. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.