A new research has shown that accelerated ice melt in west Antarctica is inevitable for the rest of the century no matter how much carbon emissions are cut.
The implications for sea level rise are “dire” and mean some coastal cities may have to be abandoned, according to scientists who were involved in the study.
While the ice sheet of west Antarctica would push up the oceans by 5 metres if lost completely, previous studies have suggested it is doomed to collapse over the course of centuries, but the new study shows that even drastic emissions cuts in the coming decades will not slow the melting.
Among other things, the latest research shows that the rate of melting of the floating ice shelves in the Amundsen Sea will be three times faster this century compared with the previous century, even if the world meets the most ambitious Paris agreement target of keeping global heating below 1.5C above pre-industrial levels.
Losing the floating ice shelves means the glacial ice sheets on land are freed to slide more rapidly into the ocean, the research found. Many millions of people live in coastal cities that are vulnerable to sea level rise, from New York to Mumbai to Shanghai, and more than a third of the global population lives within 62 miles (100km) of the coast.
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The climate crisis is said to be driving sea level rise by the melting of ice sheets and glaciers and the thermal expansion of sea water. The biggest uncertainty in future sea level rise is what will happen in Antarctica, the scientists say, making planning to adapt to the rise very hard.
But researchers said that translation of the new findings on ice melting into specific estimates of sea level rise was urgently needed.
“Our study is not great news – we may have lost control of west Antarctic ice shelf melting over the 21st century,” said Dr Kaitlin Naughten, at the British Antarctic Survey, who led the work. “It is one impact of climate change that we are probably just going to have to adapt to, and very likely this means some coastal communities will either have to build [defences] or be abandoned.”
Story was adapted from the Guardian.