Among the many devastating effects of global warming is the slowing of deep-sea circulation megacurrents. If we knew from a study published in August 2021 in the journal Nature Climate Change that the AMOC (Meridian Atlantic Overturning Circulation) megacurrent was under threat, a new study published December 22 in the same journal reports the same thing Risk for the Smoc (Southern Circulation Meridian Circulation) to the south, reports Geo.
These currents are driven by differences in temperature and salinity between the water masses. The warming of the water gradually slows down this circulation. According to the latest estimates by researchers at the University of California, Irvine, Smoc could completely cease as early as 2300 in the worst-case scenario of global warming. In the not too distant future, Smoc and Amoc risk a 42% slowdown by 2100.
A vicious circle
“This would mean a climate catastrophe similar to the melting of all of Earth’s ice caps,” oceanographer J. Keith Moore, associate professor and co-author of the study, said in a statement. Specifically, these megaflows have the task of capturing and storing the CO2 emissions released into the atmosphere. This process is made possible by the plankton, which synthesizes the carbon dissolved in the water in its shell for several thousand years.
The slowdown of these megacurrents will therefore clearly exacerbate the global warming phenomenon that is causing this slowdown in particular. At the same time, by weakening the biological activity of marine microorganisms, the role of the oceans as a “carbon sink” could also be reduced. However, both of these phenomena would still be reversible if humanity limits its greenhouse gas emissions, according to the authors of the latest study, Nature Climate Change.