Shutdown of AMOC Could Release Ocean Carbon, Increasing Global Warming

Communications Earth & Environment, 27 March 2026

The potential collapse of the major system of global ocean currents known as the Atlantic Meridional Overturning Circulation (AMOC) could cause release of large amounts of carbon from the Southern Ocean, increasing atmospheric CO2 and adding roughly 0.2°C of additional global warming. The AMOC transports warm surface water northward in the Atlantic and returns colder, denser water southward, helping regulate global climate and ocean carbon storage. Using an Earth system model, researchers simulated AMOC collapse under different warming levels and found that its collapse could trigger substantial carbon release from the Southern Ocean. Surface waters around Antarctica would sink and mix with deep carbon-rich waters, allowing stored ocean carbon to escape into the atmosphere. In addition to increasing net global warming, AMOC collapse would have extreme impacts on regional temperatures: the Arctic would cool by about 7°C, while Antarctic regions would warm by 6°C. These results highlight the role of the AMOC as a key regulator of global climate, and show how disruptions in AMOC circulation could weaken the ocean’s role as a carbon sink and dramatically alter regional temperatures.

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