How climate change and international trade will shape the future global soybean security pattern

Soybean planting is highly concentrated and sensitive to climate change, which makes global soybean security vulnerable to production fluctuations in the main producing countries. As an important trade commodity, the impacts of climate change on soybean production in the main producing countries can ripple globally through international trade. However, little is known about the spatial distribution of soybean security under future climate at the global scale. This study couples an ensemble of multi-crop models and a global economic model (GTAP, Global Trade Analysis Project) to evaluate variations in soybean yield of the top ten soybean-producing countries in the 2050s (2046–2055) and the consequent impacts on global soybean supply and price under a range of future climate scenarios. Our results show that (1) The top ten soybean-producing countries, accounting for nearly 97% of global soybean production, suffer an average soybean yield reduction of 0.82% (specific to each country: −5.81%∼7.05%), 0.43% (−23.5%∼11.72%) and 5.22% (−17.88%∼18.73%) under Representative Concentration Pathway (RCP) 2.6, RCP4.5 and RCP 8.5, respectively, when considering the fertilization effect of CO2. A substantial soybean yield loss of 19.51% (−28.86%∼2.97%) is projected under RCP8.5 without accounting for the CO2 fertilization effect. (2) Climate-induced yield reduction leads to insufficient soybean supply and higher price worldwide through the transmission of international trade, with the largest supply decline of 14.20% in Bolivia and the largest price increase of 91.19% in India. Regionally, soybean net-importing countries are more vulnerable because of the ripple effect of the soybean supply chain. For example, despite a simulated increase in soybean yield of 2.97%–18.73%, China's soybean supply will decline by 0.61%–2.27% due to import shortages from the United States and Brazil where severe soybean yield losses are witnessed. (3) Liberal trade does dampen the negative impact of climate change on global soybean supply and price by reducing trade costs and facilitating trade flows, but in soybean export-oriented regions, trade liberalization can result in increased exports at the expense of domestic soybean supply (e.g., Canada and Russia). Our findings highlight the necessity of developing a liberal trade policy that benefits all regions of the world and improving domestic soybean productivity to adapt to climate change.