
A mysterious patch of water in the North Atlantic has baffled scientists for decades. Located to the southeast of Greenland, this blob of seawater was colder between 1901 and 2021 than during the late 1800s, even as the seas around it became ever warmer.
Some scientists linked this "warming hole" to an inflow of frigid Arctic meltwater; others blamed pollution from shipping, which can bounce the sun's rays back into space. But a growing body of evidence suggests the hole has a more sinister origin — one whose impacts, if unleashed, would reach much farther than a small region of the North Atlantic.
The warming hole might be a sign that Atlantic Ocean currents are slowing down. This network of currents regulates Earth's climate, moving heat from the tropics to the Northern Hemisphere. The currents, which include the Gulf Stream, form a huge and seemingly permanent loop known as the Atlantic Meridional Overturning Circulation (AMOC).
Comment: Also recently, further south along the western seaboard: Dead gray whale washes ashore at Alameda beach, California - 4th in Bay Area so far this year