Atlantic current system (AMOC) could shut down after 2100
The Atlantic Meridional Overturning Circulation (AMOC) - the vast system of ocean currents that includes the Gulf Stream - acts like a giant conveyor belt, carrying warm water north and cold water south. This system helps keep Europe's climate mild and influences weather patterns worldwide.
A new study led by Sybren Drijfhout (Royal Netherlands Meteorological Institute) suggests this vital current system could completely shut down after 2100 if we continue with high emissions. Even with moderate emission cuts, the models show worrying signs of slowdown.
Map of the Nordic Seas and subpolar basins with currents that form part of the AMOC. Solid lines represent currents at/near the sea surface and dashed lines deep currents. Credit R. Curry, WHOI/Science/USGCRP (CC BY 3.0)
The breakdown starts in key northern seas (Labrador, Irminger, and Nordic) where cold surface water normally sinks deep in winter. But as the planet warms, surface waters stay warmer and lighter, so they don't sink as easily. This disrupts the ocean's natural mixing and weakens the entire current system, creating a downward spiral that becomes harder to reverse.
The research team used advanced climate models running far into the future (to 2300-2500) and found that all high-emission scenarios led to a complete shutdown. Worryingly, scientists are already seeing signs of weakening in these northern regions. Once a critical threshold is crossed — possibly within decades — the collapse becomes unstoppable. A shutdown could take 50–100 years, reducing heat transport to a fraction of today’s levels.
Why it matters: If this ocean conveyor belt shuts down, northwestern Europe would face much harsher summers and winters, tropical rain patterns would shift dramatically, and ice sheets would melt faster. The models might even underestimate how quickly this could happen since they don't fully account for melting ice in Greenland. Rapidly cutting emissions is our only chance to avoid crossing this dangerous point of no return.
Read the paper Shutdown of northern Atlantic overturning after 2100 following deep mixing collapse in CMIP6 projections (open access)
