NEW: Atlantic Meridional Overturning Circulation - AMOC to Weaken by 51% (Uncertainty 8%) by 2100
Posted by paulhenrybeckwith@reddit | collapse | View on Reddit | 18 comments
Zandmand@reddit
I remember my grandparents talking about harsh winters every year in Denmark. Having just had a really hard winter with up to 3 feet of snow, i am not looking forward to having that or worse every year.
Denmark and Scandinavia in general are some of the places that will probably get a lot colder in the winter when the AMOC weakens or stops entirely
Acceptable-Bell142@reddit
In my part of Scotland, a cold winter's night is about -8°C. Without the AMOC, that drops to below -30°C. We'll have below freezing nights for 6 months of the year and we'll have sea ice.
I don't think we could cope with the transition if it happens before 2100, which it probably will.
Lucky-Opportunity395@reddit
That’s based on Van Westen’s study, where this -30C value is actually the record minimum temperature that would be expected over a 10 year period.
Even then, that’s assuming 2C of warming, unrealistic freshwater hosing, and a low resolution that exaggerated the expected cooling, particularly via overestimation of sea ice feedbacks (that are implausible in reality), and underestimation of oceanic and atmospheric feedbacks. It’s more likely that the jet stream would be positioned further north and strengthened over Britain in winter, along with an inflated Azores High that would more likely just cause stormer winters, rather than colder ones
Zandmand@reddit
Last winter we had -18 for some of it which was unusual but not unheard of. The coldest I ever remember it being here was around -23.
Cultural-Answer-321@reddit
I'm going to bet, "sooner than expect".
imminentjogger5@reddit
that's a timeline most people won't give a shit about
Long-Debt6637@reddit
Well, that is later than I thought for once.
Anxious_cactus@reddit
Give it a year or two, you know it's gonna slide
NyriasNeo@reddit
"by 2100"
Is anyone gullible enough to believe that most care about 2100? Most people do not look past next week's food and next month's rent. Myopia is well documented.
Talking about 2100 is a sure way to make people care LESS, not more about climate change. Ditto of use of the term AMOC. Just go on the street and ask random people about it. It would be a miracle if more than 1 in 10 has a clue.
imalostkitty-ox0@reddit
“2100” is science’s way of saying 2040, without getting suicided in the middle of the night
NyriasNeo@reddit
and that is the laymen's way saying "I don't give a sh*t".
I know we all publish papers with our own idiosyncratic statements like "Given the limitations of available evidence, one possible explanation is..." .. meaning "i don't know shit and I am saying it anyway"
But if you want laymen to move, may be learn a bit of marketing. There is a science around it too, you know. No wonder "drill baby drill" won.
paulhenrybeckwith@reddit (OP)
NEW: Atlantic Meridional Overturning Circulation - AMOC to Weaken by 51% (Uncertainty 8%) by 2100
A few years ago, a paper analyzing results from many climate models (best at the time) argued that the chance of the AMOC )Atlantic Meridional Overturning Circulation) slowing and stopping by 2100 was 32% (uncertainty a whopping 37%) with 90% certainty.
The newest findings in the new, just published peer reviewed scientific paper that I chat about in this video are 51% (with uncertainty a much smaller 8%).
Not good.
References
Guardian article: Critical Atlantic current significantly more likely to collapse than thought Scientists say finding is ‘very concerning’ as collapse would be catastrophic for Europe, Africa and the Americas https://www.theguardian.com/environment/2026/apr/15/critical-atlantic-current-significantly-more-likely-to-collapse-than-thought
Peer-reviewed paper in Science Advances journal: C L I M AT O L O G Y Title: Observational constraints project a ~50% AMOC weakening by the end of this century Authors: Valentin Portmann, Didier Swingedouw, Omar Khattab, Marie Chavent
Abstract Climate models show considerable discrepancies in their future projections around the Atlantic, mainly due to uncertainties in the fate of the Atlantic Meridional Overturning Circulation (AMOC). Climate models suggest a re-duction in AMOC strength of 32 ± 37% by 2100 (90% probability, Shared Socioeconomic Pathways 2-4.5 scenario, Coupled Model Intercomparison Project Phase 6). To refine this estimate and reduce its uncertainty, we use four different observational constraint methods. The best one, which provides the lowest leave-one-out error, integrates a large set of observable variables using ridge-regularized linear regression—a method unusual in climate science. It gives an estimate of the AMOC slowdown of 51 ± 8% (90% probability), i.e., a weakening ∼ 60% stronger than suggested by the multi-model mean. This refinement mainly results from correcting a bias in South Atlantic surface salinity, consistent with recent studies emphasizing its role in the proximity to an AMOC tipping point. This more substantial AMOC weakening has key implications for future adaptation strategies. Direct link to free open-source peer reviewed scientific paper: https://www.science.org/doi/epdf/10.1126/sciadv.adx4298
Please subscribe to my YouTube channel. As well as my website, and YouTube, you can find me on Patreon, Facebook, Twitter/X, LinkedIn, Instagram, Reddit (multiple climate channels within), Quora, TikTok, Discord, Mastodon, Twitch, Vimeo, Bluesky, TruthSocial, Threads, Substack, Tumblr, Pinterest, etc...
bipolarearthovershot@reddit
Paul it’s Thursday night bud give it a rest!!
imalostkitty-ox0@reddit
Cut that shit out, he might take it to heart one day
banned4violence@reddit
Iceland is screwed! I’ll be dead but my grandkids will be my age.
metalreflectslime@reddit
Thanks.
Kitchen-Paint-3946@reddit
Ok great, then let’s not worry about it
StatementBot@reddit
The following submission statement was provided by /u/paulhenrybeckwith:
NEW: Atlantic Meridional Overturning Circulation - AMOC to Weaken by 51% (Uncertainty 8%) by 2100
A few years ago, a paper analyzing results from many climate models (best at the time) argued that the chance of the AMOC )Atlantic Meridional Overturning Circulation) slowing and stopping by 2100 was 32% (uncertainty a whopping 37%) with 90% certainty.
The newest findings in the new, just published peer reviewed scientific paper that I chat about in this video are 51% (with uncertainty a much smaller 8%).
Not good.
References
Guardian article: Critical Atlantic current significantly more likely to collapse than thought Scientists say finding is ‘very concerning’ as collapse would be catastrophic for Europe, Africa and the Americas https://www.theguardian.com/environment/2026/apr/15/critical-atlantic-current-significantly-more-likely-to-collapse-than-thought
Peer-reviewed paper in Science Advances journal: C L I M AT O L O G Y Title: Observational constraints project a ~50% AMOC weakening by the end of this century Authors: Valentin Portmann, Didier Swingedouw, Omar Khattab, Marie Chavent
Abstract Climate models show considerable discrepancies in their future projections around the Atlantic, mainly due to uncertainties in the fate of the Atlantic Meridional Overturning Circulation (AMOC). Climate models suggest a re-duction in AMOC strength of 32 ± 37% by 2100 (90% probability, Shared Socioeconomic Pathways 2-4.5 scenario, Coupled Model Intercomparison Project Phase 6). To refine this estimate and reduce its uncertainty, we use four different observational constraint methods. The best one, which provides the lowest leave-one-out error, integrates a large set of observable variables using ridge-regularized linear regression—a method unusual in climate science. It gives an estimate of the AMOC slowdown of 51 ± 8% (90% probability), i.e., a weakening ∼ 60% stronger than suggested by the multi-model mean. This refinement mainly results from correcting a bias in South Atlantic surface salinity, consistent with recent studies emphasizing its role in the proximity to an AMOC tipping point. This more substantial AMOC weakening has key implications for future adaptation strategies. Direct link to free open-source peer reviewed scientific paper: https://www.science.org/doi/epdf/10.1126/sciadv.adx4298
Please subscribe to my YouTube channel. As well as my website, and YouTube, you can find me on Patreon, Facebook, Twitter/X, LinkedIn, Instagram, Reddit (multiple climate channels within), Quora, TikTok, Discord, Mastodon, Twitch, Vimeo, Bluesky, TruthSocial, Threads, Substack, Tumblr, Pinterest, etc...
Please reply to OP's comment here: https://old.reddit.com/r/collapse/comments/1snmwc6/new_atlantic_meridional_overturning_circulation/ogmtfh3/