Extreme climate events and transboundary effects of global crop trade

Abstract Global warming is likely to increase the frequency of extreme climate events, triggering cascading effects in crop trade across country borders. When extreme events affect multiple trading partners simultaneously, the resulting exposure may aggregate through trade dependencies in ways that are not captured by single-location analyses. To address this gap, we develop a new metric that quantifies countries’ exposure as a trade-weighted fractional change in projected future climate extremes in trade partner countries. Our results show that, in a Mid-term period (2041–2060) exposure to hot events that occur abroad would increase nearly three times for 10% of countries via import of staple crops. Top sources of this imported exposure to remote extreme events are often major breadbaskets—including Australia and Russia—across hot, wet and dry events. Even in a Near-term period (2021–2040), twice as much exposure may be exported from these countries. Our findings show that extremes and trade can reinforce each other in a way that will substantially heighten exposure, and underscore the urgency of enhanced preparedness for interconnected climate risks.