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c0lo [soylentnews.org] writes:

(livescience) Key Atlantic current could collapse soon, 'impacting the entire world for centuries to come,' leading climate scientists warn [livescience.com]

Forty-four of the world's leading climate scientists have called on Nordic policymakers to address the potentially imminent and "devastating" collapse of key Atlantic Ocean currents.

In an open letter [vedur.is] published online Monday (Oct. 21), University of Pennsylvania climatologist Michael Mann [upenn.edu] and other eminent scientists say the risks of weakening ocean circulation [livescience.com] in the Atlantic have been greatly underestimated and warrant urgent action.

The currents in question are those forming the Atlantic Meridional Overturning Circulation (AMOC), a giant ocean conveyor belt that includes the Gulf Stream and transports vital heat to the Northern Hemisphere. Research shows the AMOC is slowing down and could soon reach a tipping point due to global warming, throwing Earth's climate into chaos.

(BBC) The Atlantic Ocean's currents are on the verge of collapse. This is what it means for the planet [sciencefocus.com]

Icy winds howl across a frozen Thames, ice floes block shipping in the Mersey docks, and crops fail across the UK. Meanwhile, the US east coast has been inundated by rising seas and there’s ecological chaos in the Amazon as the wet and dry season have switched around… The world has been upended. What’s going on?

While these scenes sound like something from a Hollywood disaster movie, a new scientific study investigating a key element of Earth’s climate system – the Atlantic Meridional Overturning Circulation (AMOC) – says this could occur for real as soon as 2050.

(arxiv) Probability Estimates of a 21st Century AMOC Collapse [arxiv.org]

Abstract

There is increasing concern that the Atlantic Meridional Overturning Circulation (AMOC) may collapse this century with a disrupting societal impact on large parts of the world. Preliminary estimates of the probability of such an AMOC collapse have so far been based on conceptual models and statistical analyses of proxy data. Here, we provide observationally based estimates of such probabilities from reanalysis data. We first identify optimal observation regions of an AMOC collapse from a recent global climate model simulation. Salinity data near the southern boundary of the Atlantic turn out to be optimal to provide estimates of the time of the AMOC collapse in this model. Based on the reanalysis products, we next determine probability density functions of the AMOC collapse time. The collapse time is estimated between 2037-2064 (10-90% CI) with a mean of 2050 and the probability of an AMOC collapse before the year 2050 is estimated to be 59±17%.

Original Submission