AMOC collapse | The catastrophe that the Atlantic Current could generate in 2030

the Atlantic Circular Current (amok) can Collapses Towards the middle of the century, or perhaps any time from 2025, especially in the 2030s, if current conditions persist. Greenhouse gas emissionsWhich will have serious repercussions on Climate of the North Atlantic And from the world.

Researchers from the University of Copenhagen publish in the journal 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 northward into the North Atlantic, suggesting that it “will collapse, with a 95 percent chance of collapse,” the University of Copenhagen said. Certainty will reach between 2025 and 2095. This is likely to happen within 34 years, that is, in 2057, which could create major challenges, especially rising temperatures in tropical regions and increasing storms in the North Atlantic region.

However, recent assessments by the Intergovernmental Panel on Climate Change (IPCC) suggest that a complete collapse of the AMOC is unlikely in the 21st century, and some experts have conflicting views on the new Danish study.

Partial stop

Peter Detlefsen, one of the researchers at Harvard University, said the AMOC cessation, which they do not rule out, may be partial: “It could have very serious consequences for the Earth’s climate, for example, by changing the way heat and precipitation are distributed.” At the world level. Authors.

“Although the cooling in Europe may seem less severe as the planet as a whole warms and heat waves become more frequent, this disturbance will contribute to further warming in the tropics, where rising temperatures have already led to difficult living conditions,” the expert noted.

For Detlefsen, these results underscore “the importance of reducing global greenhouse gas emissions as quickly as possible.” The researchers did not formulate hypotheses about what drives the AMOC change, but they noted that the logarithm of atmospheric carbon dioxide concentrations increased almost linearly over the period studied. However, the presence of other mechanisms cannot be ruled out, according to the publication.

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 direct measurements from the AMOC, which have been tracked continuously since 2004, and can provide more robust information about temperature trends.

This type of abrupt climate change last occurred during the Dansgaard-Oeschger phenomenon of the last glacial period, which was caused by the collapse and re-establishment of the AMOC. That period caused average temperatures in the Northern Hemisphere to fluctuate by between 10 and 15 degrees over a decade, a much greater rate than the current changes of 1.5 degrees over a century.

Early warning

Analyzing the details of the study in which he was not involved, Stefan Rahmstorf, from the University of Potsdam (Germany), considered that this work adds to previous studies that analyze early warning signals and reach similar conclusions.

A single study provides limited evidence, but when multiple methods lead to similar conclusions, they should be taken seriously. “Especially when we talk about a risk that we really want to rule out with 99.9% certainty,” he stressed.

“The current scientific evidence is that we cannot even rule out that a turning point will actually be crossed in the next decade or two,” the scientist added, quoted by Science Media Center (a platform that provides specialized scientific resources).

Conversely, Niklas Boers, from the Technical University of Munich (Germany), indicated his disagreement with the study results.

Although the qualitative claim that the AMOC has been losing stability over the past century is true, the uncertainties are too high for the moment of reversal to be estimated reliably. “In particular, the uncertainties in the model assumptions — which the authors oversimplified — are very high,” Boyer says.