The Gulf Stream, which scientists call the “South Atlantic Reverse Circulation” (AMOC), is said to have reached its breaking point. This is what emerges fromPublished a disturbing study in review The nature of climate changeThursday, August 5.
The researchers note thatComplete loss of stability“From your mother during the last century.”I wasn’t expecting signs of instability to actually appear, and I find it frightening, admits guardian Niklas Bowers, the study’s author, who fears this could lead to the collapse of Amoc. “We can’t let this happen‘, he warns.
change “irreversible”
The researchers’ fear is that Amoc will tend in this way.”Irreversible“Towards a new mode of operation, slower and weaker than that in place over 100,000 years ago. Already, Study published in March in review Nature GeoScience He revealed that Amok had reached its lowest level in a thousand years.
However, given the complexity of the Amoc system, it is impossible to know exactly when such a shift might occur. According to the authors of the study published Thursday, this could happen within a decade or two as well as several centuries.
Global warming on Earth and in the oceans
By constantly carrying currents of heat, carbon, and oxygen, AMOC plays an important role in regulating climate. Thanks to it, for example, Europeans can take advantage of relatively mild summers. The collapse could have catastrophic consequences: lower winter temperatures and increased hurricanes in Europe, disruption of the rain system in South America, India and West Africa, rising water levels in North America …
“Concretely, if the traffic drops very sharply, we will observe the most severe winters in Europe. To the south, in West Africa, you will notice severe droughts that will affect the crops of sorghum and millet, and will reduce the food intake of several million people.‘,” CNRS researcher Didier Sewingdo, analyzed in interview in Globalism Posted in early March. who was also worried, on Franceinfo, a decrease in the absorption of carbon dioxide, and consequently an increase in the concentration of this gas in the atmosphere, and then an acceleration of temperature rise on land and in the oceans.
“The only thing to do is to keep emissions as low as possible”
However, care must be taken, as the interactions between ocean circulation and climate remain unknown. Especially since AMOC’s future also depends on the success of policies to reduce greenhouse gas emissions on a global scale. The deterioration of the circulation of marine flows is in fact particularly disturbed by the warming of the oceans and the massive influx of fresh water from melting ice, the direct consequences of the climate crisis.
“Therefore, the only thing to do is to keep emissions as low as possible., notes Niklas Bowers, who works at the University of Potsdam. The probability of this extremely powerful forcing event increases with every gram of carbon dioxide we put into the atmosphere.“
