Scientists see stronger evidence of slowing Atlantic Ocean circulation, an ‘Achilles’ heel’ of the climate

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The Atlantic meridional overturning circulation, a system of currents, is weaker than it has been in 1,000 years

A growing body of evidence suggests that a massive change is underway in the sensitive circulation system of the Atlantic Ocean, a group of scientists said Thursday.

The Atlantic meridional overturning circulation (AMOC), a system of currents that includes the Florida Current and the Gulf Stream, is now “in its weakest state in over a millennium,” these experts say. This has implications for everything from the climate of Europe to the rates of sea-level rise along the U.S. East Coast.

Although evidence of the system’s weakening has been published before, the new research cites 11 sources of “proxy” evidence of the circulation’s strength, including clues hidden in seafloor mud as well as patterns of ocean temperatures. The enormous flow has been directly measured only since 2004, too short a period to definitively establish a trend, which makes these indirect measures critical for understanding its behavior. Continue reading.