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anlomedadMy girlie chart with 490ky years of <a href="https://climatejustice.social/tags/Milankovic" class="mention hashtag" rel="nofollow noopener noreferrer" target="_blank">#Milankovic</a> cycles, CO2, sea level, and the top line is d18O of a sediment core from within the <a href="https://climatejustice.social/tags/ColdBlob" class="mention hashtag" rel="nofollow noopener noreferrer" target="_blank">#ColdBlob</a>, see map. I think, it records AMOC shutdowns in the past. Would be intriguing to know why it shut down. Eg, 427ka, "just" before the interglacial MIS11. And why it not shut down during that very long interglacial which was ~as warm as the Holocene, and had an ice-free West <a href="https://climatejustice.social/tags/Greenland" class="mention hashtag" rel="nofollow noopener noreferrer" target="_blank">#Greenland</a> (with a leaf found just 2 years ago at rock-bottom of an ice core from there),and why AMOC instead collapsed in the middle of the following <a href="https://climatejustice.social/tags/iceage" class="mention hashtag" rel="nofollow noopener noreferrer" target="_blank">#iceage</a>. The very long interglacial MIS11 with its ice-free West Greenland and stable AMOC throughout tells me that the amount of freshwater input from melting ice on its own isn't the trigger for a collapse. But instead, the speed at which freshwater is added: very slowly like during <a href="https://climatejustice.social/tags/MIS11" class="mention hashtag" rel="nofollow noopener noreferrer" target="_blank">#MIS11</a> won't do it. Also intriguing: why the stuttering motor during the last glacial before the <a href="https://climatejustice.social/tags/Holocene" class="mention hashtag" rel="nofollow noopener noreferrer" target="_blank">#Holocene</a>?<a href="https://climatejustice.social/tags/d18O" class="mention hashtag" rel="nofollow noopener noreferrer" target="_blank">#d18O</a> from sediment cores at other locations strictly follow the ups and downs of <a href="https://climatejustice.social/tags/sealevel" class="mention hashtag" rel="nofollow noopener noreferrer" target="_blank">#sealevel</a> and <a href="https://climatejustice.social/tags/CO2" class="mention hashtag" rel="nofollow noopener noreferrer" target="_blank">#CO2</a>. This one site <a href="https://climatejustice.social/tags/IODP" class="mention hashtag" rel="nofollow noopener noreferrer" target="_blank">#IODP</a> <a href="https://climatejustice.social/tags/U1308" class="mention hashtag" rel="nofollow noopener noreferrer" target="_blank">#U1308</a> is exceptional. <a href="https://climatejustice.social/tags/paleoclimate" class="mention hashtag" rel="nofollow noopener noreferrer" target="_blank">#paleoclimate</a> <a href="https://climatejustice.social/tags/AMOC" class="mention hashtag" rel="nofollow noopener noreferrer" target="_blank">#AMOC</a>

anlomedadWeird. Maybe, I've got a logical mistake in my thinking Will <a href="https://climatejustice.social/tags/Steffen" class="mention hashtag" rel="nofollow noopener noreferrer" target="_blank">#Steffen</a> et al 2018 <a href="https://www.pnas.org/doi/10.1073/pnas.1810141115" rel="nofollow noopener noreferrer" translate="no" target="_blank">https://www.pnas.org/doi/10.1073/pnas.1810141115</a> warned in "Trajectories of the Earth System in the Anthropocene" of a "Hot House Earth" . A term that got negative press all over and the paper is still discredited in public opinion among the non-scientific community, at least. A Hot House Age is merely the term for an ice-less age in which the poles are not covered by kilometres of ice. That is called an Ice House Age. <a href="https://climatejustice.social/tags/Talento" class="mention hashtag" rel="nofollow noopener noreferrer" target="_blank">#Talento</a> et al 2021 <a href="https://esd.copernicus.org/articles/12/1275/2021/" rel="nofollow noopener noreferrer" translate="no" target="_blank">https://esd.copernicus.org/articles/12/1275/2021/</a> modelled what happens to ice ages <a href="https://climatejustice.social/tags/glacial" class="mention hashtag" rel="nofollow noopener noreferrer" target="_blank">#glacial</a> |s in several emission scenarios. Today's CO2 concentration is already moving the next <a href="https://climatejustice.social/tags/iceage" class="mention hashtag" rel="nofollow noopener noreferrer" target="_blank">#iceage</a> to later than what the <a href="https://climatejustice.social/tags/Milankovic" class="mention hashtag" rel="nofollow noopener noreferrer" target="_blank">#Milankovic</a> cycles would dictate. Scenarios for (in my opinion fictitious, unachievable) emissions of 1000 or 3000 Pg C move the next fullblown ice age to 600ky and 900ky from now. Almost a million years. No ice age. But the <a href="https://climatejustice.social/tags/AMOC" class="mention hashtag" rel="nofollow noopener noreferrer" target="_blank">#AMOC</a> is going to collapse: the convection in the Subpolar Gyre in the 2030s; the Northern branch of AMOC might tip before 2050 to later inevitably collapse, too.Certainly that increases ice mass in Greenland, Europe, and Eurasia, and Arctic Sea Ice grows back, too. And all this AMOC-related ice grows and grows, each year puts more snow on the ever increasing ice layer. I don't know how much ice is needed to meet criteria for a glacial definition. But all that Eurasian ice also buries the boreal forests under it, ie removes their carbon from the cycle. And puts an ice plug on leaking methane from <a href="https://climatejustice.social/tags/permafrost" class="mention hashtag" rel="nofollow noopener noreferrer" target="_blank">#permafrost</a> in that area. (Tho not the permafrost in the far East. I gather, that area is not prone to ice sheets from Atlantic influences and needs other triggers to form? It wasn't covered by ice in <a href="https://climatejustice.social/tags/MIS11" class="mention hashtag" rel="nofollow noopener noreferrer" target="_blank">#MIS11</a>, 420ky ago. )Weird isn't it, that ice mass models like Talento's don't factor in ever-increasing ice mass in low-to medium emission scenarios. Hm.

anlomedad<a href="https://fediscience.org/@DrEvanGowan" class="u-url mention" rel="nofollow noopener noreferrer" target="_blank">@DrEvanGowan</a> I went looking and found one from 673.3ky to 240ky. It's <a href="https://climatejustice.social/tags/KerstinBraun" class="mention hashtag" rel="nofollow noopener noreferrer" target="_blank">#KerstinBraun</a> et al 2023, data <a href="https://doi.pangaea.de/10.1594/PANGAEA.957457" rel="nofollow noopener noreferrer" translate="no" target="_blank">https://doi.pangaea.de/10.1594/PANGAEA.957457</a> 5 stalagmites from the same cave – and look, how very different their d18O and 13C are. The ups and downs are sometimes congruent and sometimes a thousand years apart?! The top 2 charts only show the 2 longest records. But <a href="https://climatejustice.social/tags/MIS11" class="mention hashtag" rel="nofollow noopener noreferrer" target="_blank">#MIS11</a> is covered in full and their location is important for <a href="https://climatejustice.social/tags/AMOC" class="mention hashtag" rel="nofollow noopener noreferrer" target="_blank">#AMOC</a> research: 33.73S°, 19.77E° 💃

anlomedad<a href="https://fediscience.org/@rahmstorf" class="u-url mention" rel="nofollow noopener noreferrer" target="_blank">@rahmstorf</a> Thanks. Also reading that new <a href="https://climatejustice.social/tags/OpenAccess" class="mention hashtag" rel="nofollow noopener noreferrer" target="_blank">#OpenAccess</a> paper by <a href="https://climatejustice.social/tags/RenevanWesten" class="mention hashtag" rel="nofollow noopener noreferrer" target="_blank">#RenevanWesten</a> on <a href="https://climatejustice.social/tags/AMOC" class="mention hashtag" rel="nofollow noopener noreferrer" target="_blank">#AMOC</a> simulation <a href="https://www.science.org/doi/10.1126/sciadv.adk1189" rel="nofollow noopener noreferrer" translate="no" target="_blank">https://www.science.org/doi/10.1126/sciadv.adk1189</a> Their slow freshwater forcing that lead to collapse after 1750 years lets me think of <a href="https://climatejustice.social/tags/MIS11" class="mention hashtag" rel="nofollow noopener noreferrer" target="_blank">#MIS11</a> , the very long interglacial 420thsd years ago, and of last year's paper where they had found a plant leaf at the bottom of the ice core in West <a href="https://climatejustice.social/tags/Greenland" class="mention hashtag" rel="nofollow noopener noreferrer" target="_blank">#Greenland</a> , indicating that it was ice free some time during MIS11. Shouldn't that freshwater input combined with , I assume, precipitation changes similar to today's due to similar temperatures, also have lead to AMOC collapse? And which proxy would tell us if that was the case? What may have endured in London or Bergen for 420ky that still tells that story? But what I know of global MIS11, AMOC didn't collapse, and Earth noving to the next ice age was a slow escalator, not a clear slide like I'd expect from after a AMOC collapse. I haven't learned much yet on Heinrich events. But the new paper also creates the impression that AMOC is also sensitive to relatively fast temperature changes when Earth is racing out of a glacial and changes her rain patterns everywhere, over ocean and land, while not at all reaching today's temperatures nor the rate of change. Must read some stuff on Heinrich, Dansgar etc. Intruiging.

anlomedadJust remembered having read a paper this year where a team had drilled an <a href="https://mst.mineown.de/tags/IceCore" class="mention hashtag" rel="nofollow noopener noreferrer" target="_blank">#IceCore</a> in the West of <a href="https://mst.mineown.de/tags/Greenland" class="mention hashtag" rel="nofollow noopener noreferrer" target="_blank">#Greenland</a> and at the bottom of the core, where the drill had literally hit rock bottom, they ... found a plant leaf. Indicating that West Greenland was not only ice free but ice free for long enough so soil for plant growth had existed. The plant grew 400 thousand years ago in <a href="https://mst.mineown.de/tags/MIS11" class="mention hashtag" rel="nofollow noopener noreferrer" target="_blank">#MIS11</a> and the climate was 1.2C over pre industrial. When I remembered, this paper just now, a plot occurred to me for a future novel on paleo climate scientists who look at West Greenland again. Like, maybe 400 thousand years into the future, when there will have been 3 more glacials with Greenland fully covered in ice. What will they find when their drill hits rock bottom? We should place a <a href="https://mst.mineown.de/tags/Tesla" class="mention hashtag" rel="nofollow noopener noreferrer" target="_blank">#Tesla</a> at the site where they found that plant leaf this year. Just put it on top of the still existing ice. It's heavy enough so it'll just sink lower and lower and also stay put once all ice has washed to the sea...

O=C=O<a href="https://mastodon.social/tags/MIS11" class="mention hashtag" rel="nofollow noopener noreferrer" target="_blank">#MIS11</a> <a href="https://en.wikipedia.org/wiki/Marine_Isotope_Stage_11" rel="nofollow noopener noreferrer" translate="no" target="_blank">https://en.wikipedia.org/wiki/Marine_Isotope_Stage_11</a>

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