Odd Ocean 'Cold Blob' Is a Warning Sign

A curious patch of stubbornly chilly water in a rapidly warming world has scientists watching the North Atlantic with unusual focus. East of Newfoundland, a large "cold blob" of well-below-normal sea surface temperatures has hung on for about a year in one of the only parts of the global ocean that hasn't significantly warmed in recent decades. That spot overlaps with a critical piece of the Atlantic meridional overturning circulation, or AMOC—the deep-ocean "conveyor belt" that shuttles warm water north and helps regulate climates from Greenland to Europe, per the Washington Post.

If the current weakens sharply or collapses, models suggest the Northern Hemisphere could cool in places, sea levels could jump regionally, and seasonal patterns could shift. There could be prolonged droughts in Africa and a deep winter freeze in Europe as a result, per CNN. In a new study, scientists say the "cold blob"—also known as the North Atlantic Warming Hole—signals the AMOC is indeed weakening, slowing the heat transfer north from the tropics, per Live Science. While this has raised fresh concerns, the UN Intergovernmental Panel on Climate Change has concluded that the AMOC is unlikely to abruptly fail before 2100.