Rapid warming could trigger Atlantic circulation collapse at lower temperatures

Scientists at Utrecht University’s Faculty of Science have shown that the Atlantic Meridional Overturning Circulation (AMOC) may tip over at much lower temperatures if the planet warms quickly. Using two climate-model runs—one with CO₂ rising at 0.5 ppm per year and another at 2.5 ppm per year, comparable to current trends—they found the slow-warming model kept the AMOC stable past +4 °C, whereas the fast-warming model saw collapse near +2 °C. Lead author René van Westen explained that the ocean’s deep layers need decades to adjust, and a warming rate around 0.3 °C per decade appears critical.

Co-authors Reyk Börner and Henk Dijkstra highlighted that rapid change leaves the circulation vulnerable, while slower change allows adaptation. The study, published in Nature Climate Change, implies that climate policies should consider not only final temperature targets but also the trajectory toward them. Slowing the rate of warming could give the Atlantic system more time to respond, reducing the chance of a sudden climate shift.