And who is going to close the Bering Strait to make all that possible? There has been no collapse of the thermohaline circulation ever since sea-levels were higher than about 50m below current levels - the depth of the Bering Strait. www.pnas.org/doi/pdf/10.1... - ThreadSky

frankwunderli13.bsky.social • 10 days ago

And who is going to close the Bering Strait to make all that possible? There has been no collapse of the thermohaline circulation ever since sea-levels were higher than about 50m below current levels - the depth of the Bering Strait. https://www.pnas.org/doi/pdf/10.1073/pnas.1116014109

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frankwunderli13.bsky.social•10 days ago

Extraordinary claims require extraordinary evidence - and I haven't seen anything of the latter.

benbarclay.bsky.social•10 days ago

That doesn’t say AMOC can’t collapse - just that the AMOC off state isn’t stable without Beting being closed. You might be interested in this more recent paper, which has Hu as a co-author.

frankwunderli13.bsky.social•10 days ago

That's not what the conclusion of the paper says.

frankwunderli13.bsky.social•10 days ago

If there is no hysteresis it means that any cooling - such as through reduced thermohaline circulation - will result in warming through a strengthening of the thermohaline circulation without any meaningful delay. Thus: no collapse and no protracted cooling (as seen in NGRIP ice core data).

benbarclay.bsky.social•10 days ago

It doesn’t show hysteresis, which is in this case a bi-stable state.

After collapsing in the Open Bering State system it *return* in less than 400 years.

But it does collapse.

frankwunderli13.bsky.social•10 days ago

Yes, for a freshwater forcing of 420.000 cubic meters per second. That's 36.3 cubic kilometers per day or 13,245 cubic kilometers per year. That's a sea level rise of 3.7 meters per century or a complete melting of the Greenland ice-sheet within about 150 years.

Ridiculous.

frankwunderli13.bsky.social•10 days ago

In case you didn't notice:

This is a simulation of meltwater pulse 1A that lead to a collapse of the thermohaline circulation (THC), after 4-500 years of this rate of melting of the ice in Canada, Europe and Siberia. Except under present day conditions, with magic freshwater inflow.

frankwunderli13.bsky.social•10 days ago

Under realistic conditions - most importantly including the lack of LGM-sized ice sheets on earth - the THC is very stable against disruption, because there is not enough freshwater anywhere near the arctic that can flow into it fast enough to accomplish that, by an order of magnitude.

benbarclay.bsky.social•10 days ago

Yes, I know the paper you cited wasn’t really focusing on the topic in question.

That’s one of the reasons I gave the link to the other, newer paper with the same author which actually is about the likelihood of a significant slowdown in AMOC in the relatively short term.

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