Antarctica to lift seas by metres per degree of warming

Paris: Raising Earth’s average surface temperature another degree Celsius will lock in 2.5 metres of sea level rise from Antarctica alone and an extra three degrees see the frozen continent lift oceans 6.5 metres, scientists warned Wednesday. These devastating increases in the global waterline — enough to cripple coastal cities from Mumbai to Miami and displace hundreds of millions of people — would unfold over hundreds to thousands of years. But the man-made greenhouse gas emissions that could guarantee such an outcome are on track to occur on a timescale measured in decades, they reported in the journal Nature.

One of the study’s most alarming conclusions is that hikes in sea level caused by a disintegrating Antarctic ice sheet — which holds enough frozen water to boost oceans 58 metres — would become dramatically larger with each additional degree of warming.