North Atlantic Cold Blob Signals Weakening of Ocean Heat Transport

Scientists have identified a persistent “cold blob” in the North Atlantic, a region of surface waters 1 °C cooler than historical averages that has been cooling for about 150 years. New research published in *Geophysical Research Letters* links the anomaly to a slowdown of the Atlantic Meridional Overturning Circulation (AMOC), the oceanic conveyor that moves heat northward. The study, led by Stefan Rahmstorf at the Potsdam Institute, warns that further weakening of the AMOC could intensify European winters, alter global precipitation patterns, raise sea level along the U.S. East Coast, and increase Atlantic storm strength. The Nordic Council has highlighted the risk of extreme cold in Iceland, noting that temperatures could plunge to –45 °C, a condition not seen since Viking times. Researchers stress the need for urgent monitoring and policy attention as the cold blob may serve as an early warning of broader climate disruptions.