In the movie The Day After Tomorrow, the world froze pretty quickly when a major ocean current, dubbed the "ocean conveyor belt", turned off.

While that was a work of fiction, slowdowns of the conveyor are possible and researchers have now found a way of giving us a few years' advance notice.


Although even 10 years' warning would be too late to do anything about preventing such an event, it could help people plan ahead to adapt, they say.

... To look for possible early warning signs of such a slowdown in the current, Ed Hawkins and Rowan Sutton of the University of Reading, UK, used a climate model developed by the Met Office's Hadley Centre.

The study "is the first to demonstrate that such rapid changes are potentially predictable," Hawkins says. "It is a first step in designing a possible 'early warning system'."