Climate & Earth Science

The Atlantic Current That Could Cool Europe — The AMOC Is in Trouble

For decades, a collapsing Atlantic ocean current was a plot device in Hollywood movies. In 2026, it has become a genuine scenario that leading climate scientists are warning could happen within this century.

• Two new studies, published in Nature and Science in 2026, put the Atlantic Meridional Overturning Circulation (AMOC) at its weakest point in at least 1,600 years.
• One team argues the probability of a full collapse has risen from roughly 5 percent to more than 50 percent, with a plausible shutdown as early as the 2050s or 2060s.
• Another European study estimates the current could be 50 percent weaker by 2100, pointing toward an eventual collapse rather than a steady decline.

The AMOC is the ocean's great conveyor belt. Warm, salty water flows northward near the surface from the tropics to the North Atlantic, where it releases its heat into the atmosphere — this is the reason a 50-degree-latitude city like Reykjavik stays livable while a place at the same latitude in Siberia is frozen. The now-cooler, saltier water sinks, then returns southward deep beneath the surface. A single cubic metre of water takes roughly a thousand years to complete the loop.

The engine is being jammed by climate change in two ways. Melting Greenland ice and record rainfall in the Arctic pour fresh water into the North Atlantic, and fresh water does not sink — it floats. At the same time, warming seas change the density balance that drives the overturning in the first place. With less sinking, the whole conveyor slows.

If the AMOC were to collapse, the consequences for Europe would be abrupt and severe. The Science authors describe "strong and rapid cooling of the European climate" — roughly 3 degrees Celsius, or up to 5 degrees Fahrenheit, per decade. That is a pace an order of magnitude faster than current global warming, and the researchers note that no realistic adaptation measure could keep up. Meanwhile, the tropical rain belts would shift, the South Atlantic could warm, and the Indian monsoon could weaken.

Crucially, this is not settled science. The same studies are contested by scientists who say the signal is buried in natural variability and that a precise timing cannot be predicted. The consensus, however, is clear enough to be urgent: the current is at its weakest in millennia, and the window to limit the emissions that drive the slowdown is the same window that drives every other climate action.