A large North Atlantic “cold blob” south of Greenland has cooled nearly 2 degrees Fahrenheit since 1900 even as much of the global ocean hits record heat, scientists say.
Researchers link that anomaly to a weakening Atlantic Meridional Overturning Circulation, the current system that carries warm water north before it cools, sinks and flows back south.
Human-driven warming is melting ice caps and adding cold, fresh water to the North Atlantic, disrupting the salinity and temperature balance that helps power the AMOC.
A full AMOC shutdown could raise sea levels along the U.S. East Coast, bring frigid winters to Europe and prolong droughts in Africa, underscoring the wider climate danger.
As a key Atlantic current collapses, could Europe face ice-age winters while the rest of the world continues to warm?
Scientists now warn of an ocean tipping point by mid-century. How will coastal cities survive the projected rapid sea-level rise?
New models show a 50% chance of a vital climate system collapse. Have we already passed the point of no return?
The Atlantic Meridional Overturning Circulation at Risk: North Atlantic Cooling, Tipping Points, and Global Impacts
Overview
This report explores the unusual cooling anomaly, known as the 'cold blob,' in the North Atlantic south of Greenland and Iceland, which stands out against the global trend of rising sea-surface temperatures. Scientists are closely monitoring this region because it signals broader changes in ocean circulation, especially the weakening of the Atlantic Meridional Overturning Circulation (AMOC). The AMOC acts as a global climate regulator by moving warm, salty water northward, where it cools, becomes denser, and sinks. Disruptions to this process, mainly from increased freshwater due to melting ice, threaten to further weaken the AMOC, with serious consequences for global climate stability.