Rahmstorf Study Ties 1°C North Atlantic Cold Blob to Weaker AMOC Since 1955
Updated
Updated · New Scientist · Jun 4
Rahmstorf Study Ties 1°C North Atlantic Cold Blob to Weaker AMOC Since 1955
3 articles · Updated · New Scientist · Jun 4
Summary
Cooling to 1,000 meters and declining surface heat loss since 1955 point to weaker Atlantic heat transport, leading Stefan Rahmstorf’s team to link the North Atlantic “cold blob” to a slowing AMOC rather than mainly to winds.
The study uses climate reanalyses built from satellites, buoys and ships, arguing the ocean is delivering less warmth into the region southeast of Greenland, where temperatures have cooled by as much as 1°C despite broader global warming.
Rahmstorf said the result suggests Atlantic circulation has been changing for decades and raises concern that the subpolar gyre could also tip, potentially bringing serious climate impacts to western Europe as early as the 2040s.
The finding remains contested because ocean surface heat flux was inferred rather than directly measured, and other researchers say stronger winds, clouds or shifts in currents could still explain part of the cold blob.
As a vital ocean current falters, could Europe face a deep freeze within the next decade?
A mysterious 'cold blob' defies global warming, but is it a warning of catastrophic, worldwide climate shifts?
The North Atlantic Cold Blob and AMOC Weakening: Tipping Point Risks, Global Impacts, and Urgent Policy Responses
Overview
The North Atlantic Cold Blob is a striking climate anomaly, marked by a long-term cooling trend in the subpolar Atlantic, which stands out against global warming. This unusual pattern is closely linked to the weakening of the Atlantic Meridional Overturning Circulation (AMOC), as shown by climate models and observed changes in ocean currents. The AMOC has slowed significantly since the mid-20th century, reducing heat transport to the North Atlantic and causing the cold blob. This cooling serves as a clear signal of AMOC weakening, highlighting a serious risk of rapid changes in the climate system that demands urgent attention.