The Atlantic Circular Current (AMOC) could collapse by mid-century, or potentially any time from 2025, if greenhouse gas emissions continue, with serious repercussions for North Atlantic and global climate.
Researchers at the University of Copenhagen publish in Nature Communications a study on estimates of the future of the AMOC, a large system of ocean currents that transport warm water from the tropics to the North Atlantic.
The AMOC "will collapse, with 95% certainty, between 2025 and 2095. This will most likely happen in 34 years, in 2057," which could bring big challenges, particularly warming in the tropics and increased storms in the North Atlantic region, he told the University of Copenhagen.
The AMOC shutdown, which does not rule out that it may be partial, "could have very serious consequences for the Earth's climate, for example, by changing the way heat and precipitation are distributed globally," said Peter Ditlevsen, one of the authors.
The expert noted that "while Europa's cooling may appear less severe as the planet as a whole warms and heat waves become more frequent, this disruption will contribute to further warming of the tropics, where rising temperatures have already led to difficult living conditions."
These results underline, for Ditlevsen, "the importance of reducing global greenhouse gas emissions as soon as possible."
The team made their calculations using advanced statistical tools and data on sea surface temperatures in the North Atlantic between 1870 and 2020 as a proxy for AMOC.
These records go back much further than the AMOC's direct measurements, which have been tracked continuously since 2004, and can provide more robust information on temperature trends.
Analyzing the details of the study, in which he has not participated, Stefan Rahmstorf, from the University of Potsdam (Germany), considered that this work adds to previous studies that analyze early warning signs and reaches similar conclusions.
The scientist, quoted by the Science Media Center (a platform that offers expert scientific sources) added that "the current scientific evidence is that we cannot even rule out that a tipping point will be crossed already in the next decade or two."
However, recent assessments by the International Panel on Climate Change (IPCC) suggest that a full collapse of the AMOC in the 21st century is unlikely, and some experts have conflicting views on the new Danish study. For example, Niklas Boers of the Technical University of Munich (Germany) indicated his disagreement with the results of the study.
According to Boers, although the qualitative statement that the AMOC has been losing stability in the last century is true, the uncertainties are too high to reliably estimate the moment of inflection: "In particular, the uncertainties in the assumptions of the model -very simplified by the authors- are too high".
