AMOC slowdown accelerates

The Atlantic meridional overturning circulation (AMOC), a critical oceanic system often described as an "oceanic conveyor belt," has been slowing down at an unprecedented rate. This system plays a fundamental role in the global climate by moving heat from the tropics to the Northern Hemisphere.

Potential consequences of AMOC decline

Scientists warn that by the end of the century, its speed could decrease by half compared to its historical levels. The consequences of such a slowdown could be severe, including glacial winters in Europe, rising sea levels in North America, and disruptions to vital monsoons in Africa and Asia.

AMOC collapse may be temporary

While the scientific community has long raised concerns about the AMOC's weakening, recent research suggests that the collapse of the AMOC could be temporary. According to Chuncheng Guo from the Danish Meteorological Institute, there is a linear relationship between global average temperature and the response of the AMOC. A climatic cooling could lead to a resumption of the Atlantic circulation.

Modeling the impact of warming on AMOC

Guo and his colleagues used a state-of-the-art climate model to simulate the impact of increasing global temperatures due to carbon emissions on the intensity of the AMOC. They modeled a temperature increase of 0.2°C per decade, slightly lower than the current rate of warming. Their findings indicate that even if the AMOC weakened significantly, it would not completely stop, even with a warming of up to 10°C.

Carbon capture challenges

The researchers also analyzed a scenario where the world reaches carbon neutrality and a global climate cooling occurs. In this case, the AMOC would begin to strengthen in a few decades. However, achieving this would require removing enormous amounts of carbon from the atmosphere and storing it long-term. Currently, about 2 million tonnes of carbon are captured annually, or 0.1% of human annual emissions.

Risks of AMOC recovery

René van Westen, an oceanographer at Utrecht University, warns that a restart of the AMOC after its decline could plunge European climate into even greater chaos, exposing it to accelerated warming after a spectacular cooling period. Both Guo's projections and van Westen's estimates remain to be confirmed. Current research by German scientists is replicating the experiment conducted in Denmark with ten different climate models to observe the variability of the results.