The threat to the Gulf Stream

Reported in The Week 13 March 2021, page 21

The Atlantic current system that underpins the Gulf Stream – and ensures Europe’s mild climate – is weaker now than it has been for 1,000 years, a study has found, and climate change is likely to be the cause.

Further weakening of the Atlantic Meridional Overturning Circulation (AMOC), a “conveyor belt” which brings warm water from the Gulf of Mexico to the north Atlantic, could lead to more storms battering the UK, heatwaves across Europe, and rising sea levels on the east coast of the US.

The AMOC has been measured directly since 2004; researchers studied sediments and Greenland ice cores to estimate historic patterns.

They believe the current has already slowed 15% since 1950, and that if the planet continues to warm, it could be 45% weaker by the end of this century, bringing it dangerously close to a tipping point, where it becomes irrevocably unstable and at risk of collapse.

“The consequences of this are so massive that even a 10% chance of triggering a breakdown would be an unacceptable risk,” said study co-author Stefan Rahmstorf, of the Potsdam Institute for Climate Impact Research.