“Gulf Stream could collapse as early as 2025“, “The ocean currents that regulate global temperature could stop in 2025 with serious consequences for the climate” either “Climate change could cause a glaciation of Europe“. During the last few years, the news of the “announced death of the AMOC” has filled dozens of articles on the internet. Here in Xataka too.
Well, a group of researchers just raised your hand in the middle of the bustling climate science scene and have said that perhaps we are not rushing.
Let’s talk about AMOC. The Atlantic Meridional Overturning Circulation is the North Atlantic branch of the thermohaline circulation. Since the sun does not heat the sea equally everywhere and freshwater flows reach the ocean at very specific points, this is the basic mechanism by which the oceans balance differences in temperature and salinity.
The AMOC is a good example of this regulation. After all, as explained from AEMETit is a “north-south oceanic flow on the scale of the Atlantic basin that begins with sinking to the bottom of cold sea water off Greenland, subsequently flowing south, and being replaced by warmer water flowing in the surface from the south, transferring heat from the tropics to the east coast of North America and the west coast of Europe.
Therefore, it is a key mechanism.
What would happen to us without the AMOC. “Without it, Western Europe and eastern North America would cool significantly, with a host of potential adverse effects,” said Sánchez Laulhé. We are talking about a “generalized cooling throughout the North Atlantic and northern hemisphere in general” that would collapse the temperature in Europe, drop several degrees and cause a “strengthening of winter storms, with more and more powerful explosive cyclogenesis” and a “greater proportion of precipitation falling as snow throughout Europe”.
No wonder it has climatologists worried.
In fact, we have talked about it for the last few years. We have talked a lot. And, despite this, it is not clear what is going to happen. On the one hand, we know that the current has disappeared on other occasions and (at least on a theoretical level) that global warming may be a factor that weakens it. On the other hand, the measurements that have been carried out said that the AMOC remained stable.
So? What are we left with? To answer that question, a team of scientists from the Woods Hole Oceanographic Institution (WHOI) decided to quantify the recent history of the current to see what we could expect. The methodology is new, but it is interesting: they have studied two sets of reanalysis data on air-sea heat flux.
As Martín León explained“Since there are many processes that lead to large interannual variability in the AMOC, [estos datos] “are more strongly correlated on those time scales, as opposed to annual averages.”
According to just published in ‘Nature Communications’their conclusions are very striking: the AMOC would not have decreased in the last 60 years. Obviously, this does not mean anything about its medium-term future; but it does seem clear that the effects that we should have seen have not occurred.
What can we expect? Nobody is very clear. According to Nicholas P. Foukalassistant professor at the University of Georgia and co-author of the study, the most optimistic reading is that “this work indicates that there is still time to act before we reach that potential tipping point.”
Let’s hold on to it.
Image | Sean P.
In Xataka | We have been fearing the fading of the AMOC current for years. We have good news
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