New research on the Atlantic meridional overturning circulation (Amoc) shows the most pessimistic modelling about its possible collapse to be the most accurate one.
As The Guardian reports, the researchers examined four different ways of using real-world observations to assess the models.
“They found a method called ridge regression, which had been little used in climate science before now, provided the best results,”it says.
AMOC is central to the global climate system and has been identified as being at its weakest for 1,600 years as a result of the climate crisis.
The new research, published in the journal Science Advances, combined “real-world ocean observations with the models to determine the most reliable”, the newspaper reports.
They found an estimated slowdown of 42 per cent to 58 per cent in 2100, a level almost certain to end in collapse.
A collapse of AMOC would have devastating results, shifting the tropical rainfall belt on which many millions of people rely to grow their food.
It could plunge Western Europe into extreme cold winters and summer droughts, and add 50-100cm to already rising sea levels around the Atlantic.
Valentin Portmann, at the Inria Centre de recherche Bordeaux Sud-Ouest in France, who led the new research, said that “we found that the Amoc is going to decline more than expected compared to the average of all climate models”.
“This means we have an Amoc that is closer to a tipping point,” Portmann said.
Stefan Rahmstorf, at the Potsdam Institute for Climate Impact Research in Germany, described the result as “important and very concerning”.
“I now am increasingly worried that we may well pass that Amoc shutdown tipping point, where it becomes inevitable, in the middle of this century, which is quite close,”he said.
Read The Guardian here
