"Nobody knows why?" ah come on, there are plenty of scientist researches and theories, explaining exactly this scenario. For the tl;dr group: rewatch "the day after tomorrow"! (But not this fast and dramatically).

Full article: https://archive.ph/2024.08.23-021803/https://www.newscientist.com/article/2444394-part-of-the-atlantic-is-cooling-at-record-speed-and-nobody-knows-why/

Key points:

Temperatures in that part of the Atlantic cooled off more rapidly than at any time in records extending back to 1982. This sudden shift is perplexing because the strong trade winds that normally drive such cooling have not developed.

“We’ve gone through the list of possible mechanisms, and nothing checks the box so far.”

“It’s the latest episode in a string of events for a climate system that’s gone off the rails for a number of years,”

Checkmate atheists