The last time the northern Atlantic current shut down, parts of Western Europe were covered in glaciers.
The climate models are extremely accurate within certain ranges. When you get outside those ranges, previously unknown tipping points like this will start to manifest themselves.
It’s the difference between predicting what a piece of precision machinery will do when it’s new vs after it’s been dropped and hit with a sledgehammer.
This is why the 1.5C global warming goal was irresponsibly high. We’ll cross it in ~ 18 months, so expect more terrible news like this article’s findings as we get further and further away from well-understood climatology.
https://berkeleyearth.org/global-temperature-report-for-2024...