If greenhouse gas emissions continue to increase at their present rate, then, in Antarctica alone, enough ice will have run into the sea by the end of the century to raise the high tide mark worldwide by a metre according to Tim Radford at Climate News Network.
Until now, most of the global warming has occurred in the Northern hemisphere, where climate scientists have been warning about the accelerating melting of the Arctic and Greenland ice sheets. But most had been able to take comfort that the Southern hemisphere has stayed cold, and that the Antarctic ice seemed to be stable. This, however, may be changing as surface meltwater of the kind seen in the Arctic combines with warmer seas to accelerate the rate of melting.
This will come as bad news to emergency managers around the planet as they struggle to work out the best approach to sea level rise in our coastal cities. If polar and glacial ice melt is accelerating, and if the Antarctic ice sheet is following the pattern seen in the north, the inevitable conclusion must surely be that billions of people living in coastal towns and cities – including London, New York and Miami – will have to be resettled; and possibly in years rather than decades.