Sudden and gradual climate impacts threaten global food systems in a world connected by trade

Climate-driven resource changes threaten the sustainability of global food production systems. Whether countries are exposed to shocks in addition to long-term gradual climate impacts is critical for designing climate adaptation policies. To quantify future sudden and gradual exposure, we analyzed global model simulations of agriculture, fisheries, and water sectors. We find that countries are highly exposed to co-occurring shocks at the end of the century regardless of the climate change scenario. 22 countries are projected to be simultaneously exposed to shocks and gradual cross-sector climate impacts under the high greenhouse gas emission scenario. Synchronous resource declines are of particular concern for national food security and appear more predominant for co-occurring gradual declines than for shocks. Under substantial and sudden climate impacts, we show that some countries, but not all, could benefit from existing preferential trade agreements when other signatories are less impacted by climate change. In our interconnected world, institutions need to quickly adapt to sudden and gradual climate impacts from local to international scales to ensure a sustainable food supply.