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Probability Estimates of a 21st Century AMOC Collapse
- dayofthedaleks 2y agoI appreciate an abstract that doesn't beat about the bush: 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%. We'll miss you, Gulf Stream.
- roughly 2y agoWe really, really will.
- bendigedig 2y agoThe AMOC and the Gulf Stream are two separate systems.
- cube2222 2y agoFor those curious, I found this article[0] going into the details, differences, and interactions between them. TLDR: the Gulf Stream originates from a very different phenomenon than the AMOC and is not at risk of collapse. A small part of the heat transported by the Gulf Stream does originate from the AMOC though, but its collapse would be much less severe than a full collapse of the Gulf Stream. [0]: https://bigthink.com/strange-maps/gulf-stream-collapse-amoc/ https://bigthink.com/strange-maps/gulf-stream-collapse-amoc/
- alkyon 2y agoThe Gulf Stream is part of the AMOC.
- candiddevmike 2y agoWonder how much immigration this will create from northern Europe. AIUI the collapse will make those countries quite chilly.
- huuhee3 2y agoI wonder how the summers would be under this scenario. Cold winters alone wouldn't be such a huge problem, but if food production collapses then we'll be in trouble.
- scheme271 2y agoI think both would be an issue. Most of Europe is pretty far north with the equivalent latitudes in Canada not having much agriculture or people living there frankly. Edinburgh is just slightly south of Juneau so I think any growing season would end up being too short for most crops.
- lkrubner 2y agoI worry that these scientists are focused on the 21st Century simply because many people will only care about this if it happens during our lifetimes. But if we care about our great-grandchildren, we should also be worried about the 22nd Century, and the possibility that the Gulf Stream will collapse before the year 2200 is great.
- ben_w 2y agoPredicting things that far ahead is almost impossible. Looking back, the greenhouse effect of CO2 was known in the 1800s, but even at the end of that century people thought it would take a millennium and be good. Looking forward, it's technically possible (yes I have done the maths) to build a global power grid today such that the Scaninavian arctic midwinter can be powered by solar panels in New Zealand, but only China makes enough aluminium and only China has demonstrated any interest in attempting massive infrastructure projects of this kind for soft power projection. When do we get von Neumann replicators? Do we make GM algae that turn atmospheric CO2 directly into crude oil to substitute fossil oil in the petrochemical industry? Will fundamentalists Hindus create a synthetic disease that induces an allergy to beef thus causing an end to cattle farming? Will the Russian invasion of Ukraine escalate into WW3? I can't tell which specific big things will radically change the world, but I am sure there's going to be at least one every 25 years — one between today and 2050, at least two more by 2100, and at least four between 2100 and 2200.
- IIAOPSW 2y ago>Looking back, the greenhouse effect of CO2 was known in the 1800s, but even at the end of that century people thought it would take a millennium and be good. IIRC Charles Babbage wrote in his survey of British Industry for the royal society words to the effect of "it is not presently known how exactly the coal exhaust is recycled back into the ground". Maybe some people correctly guessed that it wasn't recycled at all and in fact is an expendable (albeit quite large) resource, but their guess was as good as any other and far from something that was widely known and believed.
- 2y ago
- sillywalk 2y agoFrom a news article[0] that links to the paper: " “All the negative side effects of anthropogenic climate change, they will still continue to go on, like more heat waves, more droughts, more flooding,” he told CNN. “Then if you also have on top of that an AMOC collapse … the climate will become even more distorted.” ... The impacts of an AMOC collapse would leave parts of the world unrecognizable. In the decades after a collapse, Arctic ice would start creeping south, and after 100 years, would extend all the way down to the southern coast of England. Europe’s average temperature would plunge, as would North America’s – including parts of the US. The Amazon rainforest would see a complete reversal in its seasons; the current dry season would become the rainy months, and vice versa. " [0] https://lite.cnn.com/2024/08/02/climate/atlantic-circulation-collapse-timing/index.html https://lite.cnn.com/2024/08/02/climate/atlantic-circulation...
- warkdarrior 2y agoNice, so that's how we counteract climate change!
- Ar-Curunir 2y agoThat is climate change...
- deleted 2y ago[deleted]
- actionfromafar 2y agoI'm sure the US and EU would not do anything crazy if its crops started failing.
- Vecr 2y agoPournelle was kind of right then? Solar heating satellites when?
- CalRobert 2y agoThis seems like it should be the front page story on every news outlet. “Your kids will live in a frozen wasteland and perhaps die of starvation or conflict by middle age” is a big deal, is it not? It is to me.
- ben_w 2y agoIt's more like "Europe north of about Paris will look like southern Canada already does", which is bad but not necessarily catastrophic. (Unless this leads to a war, which it might).
- Ekaros 2y agoHmm, so obviously we have to compensate with even more CO2 and other greenhouse gasses. It is not unreasonable solution for those living the area.
- ben_w 2y agoThe people living in the entirety of Europe combined are outnumbered by a factor of 10 by people who very much won't let them. :P
- RandomLensman 2y agoHow?
- ben_w 2y agoThe usual methods. Not selling them stuff to burn, followed by military involvement if they try to manufacture super-greenhouse gases. Bear in mind that Europe trying to compensate for an AMOC collapse with more greenhouse gases would involve enough greenhouse gases to make India uninhabitable and that India has nukes, and that such a temperature change would significantly alter the agricultural productivity of the USA and the USA has nukes, and that half of China is a desert and China has nukes. I'm not sure if that kind of change would require global changes sufficient to melt the Greenland and Antarctic ice sheets, but if it did then that would also result in basically every costal nation also considering it an existential threat and thus warranting military action to prevent, including the UK.
- bendigedig 2y ago[flagged]
- hyperpape 2y agoCan anyone comment as to how seriously to take this paper? One paper is ultimately just one paper. The Wikipedia page on the AMOC (https://en.wikipedia.org/wiki/Atlantic_meridional_overturning_circulation https://en.wikipedia.org/wiki/Atlantic_meridional_overturnin...) links to a page summarizing some scientists’ reactions: https://www.sciencemediacentre.org/expert-reaction-to-paper-warning-of-a-collapse-of-the-atlantic-meridional-overturning-circulation/ https://www.sciencemediacentre.org/expert-reaction-to-paper-... However, I have no idea if this is representative or not.
- netsharc 2y agoThose reactions are to the paper by 2 Danes, as covered in this article: https://www.wired.com/story/amoc-collapse-atlantic-ocean/ https://www.wired.com/story/amoc-collapse-atlantic-ocean/ HN discussion: https://news.ycombinator.com/item?id=41087977 https://news.ycombinator.com/item?id=41087977
- yodon 2y agoThere are about 20 major climate simulation models focused on ocean calculations at different research labs around the world. All of those models show the AMOC to be meta-stable (meaning it rapidly flips from on to off, as opposed to long gradual slowing). All of those models show the AMOC is on track to shut off "soon." All of those models show an AMOC shutoff event to be very serious, particularly for Northern Europe, but also for the world as a whole. Prior to this paper, the estimates on what "soon" meant were not very good and generally took the form of "it could be this century, or it could be in the next couple centuries." This paper has not been through peer review yet, but the authors are significant participants in the field. The paper is trying to answer one of the most important question in science right now, which is how long until the AMOC shuts down and what signals should one watch for to improve that prediction.
- bikenaga 2y agoFor another point of view, see: "Uncertainties too large to predict tipping times of major Earth system components from historical data" - https://www.science.org/doi/10.1126/sciadv.adl4841 https://www.science.org/doi/10.1126/sciadv.adl4841 Their primary example is the AMOC.
- stubish 2y agoIs it really a different point of view? You have one paper estimating a time period and probabilities. And another paper stating that these estimates are inaccurate, and the best we can do without working out ways of doing the calculations that don't rely on historical record.
- nforgerit 2y agoStefan Rahmstorf[0] has been talking quite a lot about this in the recent 3-5 years, with a rising urge over time. This paper perfectly fits what he was telling about AMOC in a Keynote a month ago[1]. [0] https://en.wikipedia.org/wiki/Stefan_Rahmstorf https://en.wikipedia.org/wiki/Stefan_Rahmstorf [1] https://www.youtube.com/watch?v=ZHNNW8c_FaA https://www.youtube.com/watch?v=ZHNNW8c_FaA "One of the most ominous risks for Europe is that of a major change in Atlantic ocean currents. Recent science suggests it has been greatly underestimated in the past -including by me, having worked on it for over 30 years. Here Prof. Rahmstorf presents his keynote in Vilnius in May 2024."
- layer8 2y agoHere is an article by Rahmstorf that roughly corresponds to his talk (for those who prefer that to a video): https://tos.org/oceanography/article/is-the-atlantic-overturning-circulation-approaching-a-tipping-point https://tos.org/oceanography/article/is-the-atlantic-overtur...
- nforgerit 2y agoThe main problem is not even the ice wasteland which northern Europe would be but the dramatic temperature gradient to the Mediterranean which means storms and weather extremes we've never seen before.
- layer8 2y ago> 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%. So apparently the “mean” is different from the 50% point. Would that be the median? And wouldn’t that be the more interesting point?
- josh-sematic 2y agoThe “50%” point is the median. So, the point at which it is just as likely to have happened as to not have happened. The mean will in general be different from the median if the distribution is skewed. Here the mean is pulled a little higher than the median by a few years with a “long tail” of estimates in the later years. The distribution can be seen in figure 4(b)