The point which worries me most: Most People assume it will be a linear process going down from 100% to zero

[no_pixels@social.cologne]

RE: https://fediscience.org/@rahmstorf/116410107922936590

The point which worries me most:
Most People assume it will be a linear process going down from 100% to zero.
But isn`t it like that the AMOC needs a certain momentum to support itself?
So what will be the breaking point which leads to a sudden stop? Will it be at 50%, 30% or when?
#Climatechange #Massextinction #culturecollaps

[anlomedad@fedifreu.de]

@no_pixels

It's a huge ocean current. Flowing all the way from Antarctica to Iceland.
From memory, just as an illustration of what I mean with "huge": one stage of the north-flowing current traverses the Atlantic from Africa to Brazil. For an ocean signal to travel this distance it takes 5 to 14 years (something to do with how "planetary waves" work).

This huge being doesn't suddenly switch off. In fact, it never has suddenly switched off but each time, the AMOC took a century or so to die.
And Greenland's temperature evolution shows that nicely too.

But AMOC has 2 branches in the North Atlantic. One that hugs Europe, and another that plays around South of Greenland and in Canada's waters.
The latter one collapses first. Which has a short-lasting but interesting effect on the European branch: it gets stronger for a short while = more heat transport.
But then it resumes its slowdown toward the OFF state.

The chart here shows Greenland temperature as white line. Covered are the centuries from 90 thousand years in the past to 2thousand years into the future.
All the ups and downs in the white line are AMOC collapses.
The last serious drop on the right hand side of the chart shows how the last European OFF took 100 years for completeness. https://fedifreu.de/@anlomedad/116299979401384855