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That the two AMOC branches collapse at different times can be seen in this image.

The lines in the chart are a few proxy time series in 100 year resolution from 90ka to 300 years ago. The background shapes are Milancovic cycles.
#AMOC stopped and restarted multiple times, best seen in the white line which is a proxy for local Greenland temperature.

About 14.5ka, 14.5 on the x-axis, #Greenland temperature stops its upward race and drops very quickly. I think, this is the convection collapse in the Subpolar Gyre they talk about in the video.
It's when, from top to bottom in the chart: the bright red Andes Glacier index halts its downward slope and plateaus for the whole period of the collapsing and restarting AMOC;
the tentative Sahara greening is halted, blue line;
while noticeably, the dark red Asian monsoon and the pink CH4 methane line still increase.
These two only crash when Greenland feels the last dramatic, rapid temperature drop.

This last bottoming out takes 100 years, and lasts for 1200 years, from 12.8ka to 11.6ka.
Then it takes less than 100 years for temperature, methane and monsoon to climb back up to previous levels.

The bright red tropical Andes Glacier Index and the blue Sahara proxy stay unfazed throughout. But in the aftermath of all this atmospheric re-arranging, the Sahara proxy suddenly flickers, then it tipps – into a lush green Sahara!
(So when the blue line drops, it means that it rains a lot in the Sahara.)

On the side:
4,200 years ago, something called the 4.2ky event happens. The Sahara flickers. The red Glacier Index records a regrowth.
And from 2.9ka, the Sahara tipps. And dries out rapidly. And the glacier has another short, larger growth period.
The Asian monsoon also experienced a hickup 4,200 years ago.

Maybe that was a global event. Maybe. Although methane did not flicker – but this might an artefact of low time step resolution.

Anyway. That's how the last AMOC collapse went. In an Earth System that was crawling out of the last ice age.
It collapsed in 2 stages, first the Subpolar Gyre and Labrador Sea convection stopped. And much later, the European branch stopped too.
Again: In an Earth System that was crawling out of the last ice age. So not to be taken as blueprint for what we're setting into motion this time round.
#PaleoClimate #ClimateChange

Hands Off Greenland

12/x

#Greenland #Denmark #Trump #US #USA #USPol #Politics #NATO

@HowRu68

No, the Europeans need a NEW transalantic defence alliance (read: Canada), without the US.

They will never be trustworthy again.

#trump #usa #eu #nato #canada #denmark #greenland #norway