Fresh water from melting ice is putting the North Atlantic current at risk Alban Kakulya/Panos

The ocean current that gives western and northern Europe a relatively mild climate might be at greater risk of shutdown than we thought. If the North Atlantic current – the northern segment of the Gulf Stream – did grind to a halt the effects could be severe, from greater sea-level rise on Atlantic coasts to more intense droughts in Africa.

Surface seawater in the subpolar region chills during the winter months, which makes it so cold and dense that it sinks. This process, known as ocean convection, …