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From: https://lemmygrad.ml/post/11227040/8019202
This appears to be a high quality article:
Scientists tried to quantify weakening ocean currents. They determined that the current is further north by 50km as confirmed by satillight imagry. A Model predicts that as the currents get weaker, it goes further north due to less tug from other southern currents. The model simulation gives slight movements in current (50 km at a time) across 400 years before a sudden jump far northward and 2 years before complete collapse. If it collapses then land climate in Europe will get far harsher (very hot to very cold in short period) which has agriculture and energy consumption impacts.