The Atlantic cold blob south of Greenland and Iceland has cooled by nearly 1°C since 1900, even as most of the world’s oceans warmed, according to a new study.
Researchers linked the anomaly to a weakening of the Atlantic Meridional Overturning Circulation (AMOC) in a paper published in Geophysical Research Letters. The system moves warm tropical water northward and helps regulate the climate across the Northern Hemisphere.
The study found that the cooling reaches below the ocean surface. Researchers said the pattern points to reduced ocean heat transport rather than to winds or surface heat loss alone.
Stefan Rahmstorf, a climate scientist at the Potsdam Institute for Climate Impact Research and an author of the study, said the signal shows a change in the movement of ocean heat. “It is changing ocean heat transport,” Rahmstorf said, according to Scripps News.
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Scientists have long studied the North Atlantic cold blob as a possible sign of stress in the AMOC. The latest paper says real-world observations and climate models support a link between the cooling patch and a slowdown in the current system.
A new study has identified an unexpected factor influencing India's monsoon: a massive cooling zone in the North Atlantic known as the "Cold Blob." Scientists say this distant patch of cold water may be altering jet streams, shifting rainfall patterns across India and even… pic.twitter.com/1oeJE8ch5O
— The Federal (@TheFederal_News) June 15, 2026Researchers have warned that a major AMOC slowdown could affect European temperatures, rainfall patterns and sea levels along parts of the United States coast. The study did not say a full collapse is imminent, but it added evidence that the ocean system is weakening.
