The simulated slowdown shifts rainfall southward and cools parts of the Northern Hemisphere, with effects the authors say are effectively irreversible on human timescales once triggered.
Regional losses were far steeper than the global average: Germany and Ukraine lost up to 19% of cereal yields, Canada 12%, while India, Pakistan and parts of China saw sharp rainfall declines.
The study estimates average global food prices could rise 17% to 40%, with some years seeing cereal losses above 10% as stockpiling and export restrictions amplify shortages.
Researchers and outside experts said the non-peer-reviewed work is a proof of concept rather than a precise forecast, but it highlights how an AMOC collapse could deepen reliance on food trade.
Could a collapsing ocean current trigger a sudden global food crisis and send grocery prices skyrocketing worldwide?
Are our climate models hiding a sudden ocean circulation collapse that could completely rewrite global trade?
If rapid warming paradoxically freezes the Northern Hemisphere, which nations will survive the resulting agricultural shockwaves?
Global Food Security at Risk: The Catastrophic Agricultural and Economic Impacts of an AMOC Collapse
Overview
Rapid global heating is causing Arctic waters to cool more slowly, which slows down the sinking of warm water and weakens the Atlantic Meridional Overturning Circulation (AMOC). This slowdown lets more freshwater from rainfall and melting ice accumulate on the ocean surface, further reducing water density and creating a feedback loop that accelerates AMOC weakening. As the AMOC weakens, less salt reaches the North Atlantic, leading to density changes that temporarily strengthen the Nordic Seas Overturning Circulation before both systems risk a rapid collapse. If the AMOC collapses, global weather patterns and crop yields would be severely disrupted, threatening food security and economic stability worldwide.