A vast patch of cooling water in the North Atlantic known as “cold blob” or “warming hole” is drawing renewed scientific attention as experts warn it could significantly alter global weather patterns.
Located south of Greenland, the subpolar North Atlantic is the only place in the world to have cooled significantly in the 19th century, dropping by nearly 1C since 1900. Scientists believe the cooling is linked to a slowdown of the Atlantic Meridional Overturning Circulation (AMOC), the vast ocean current system that transports warm water northward and helps keep Europe mild.
As climate change melts the Greenland ice sheet, fresh water flows into the North Atlantic and floats on the surface, preventing salty water from sinking, weakening the AMOC’s “engine.”
Research from Penn State, published in Nature Communications, found the relationship between the AMOC and the cold blob follows three distinct phases rather than a uniform connection.
The simulations project the current will decline to its lowest-strength regime by 2100, with the cold blob’s most pronounced temperature shift occurring as late as 2067 or as early as 2021.
Meanwhile, research from Oxford academics found that of 91 national adaptation plans submitted to the UN, only two (Brazil and Ireland) even mentioned the AMOC. The authors warned that a collapse could bring winter cold extremes of -20 degrees Celsius in London and weaken West African and Indian monsoons, urging governments to stress-test long-term investments against such scenarios.
