A key area of ice in west Antarctica may already be unstable enough to cause global sea levels to rise by three metres of ocean rise, scientists said on Monday.
The study follows research published last year, led by Nasa glaciologist Eric Rignot, warning that ice in the Antarctic had gone into a state of irreversible retreat, that the melting was considered “unstoppable” and could raise sea level by 1.2 metres.
This time, researchers at Germany’s Potsdam Institute for Climate Impact Research pointed to the long-term impacts of the crucial Amundsen Sea sector of west Antarctica, which they said “has most likely been destabilized”.
While previous studies “examined the short-term future evolution of this region, here we take the next step and simulate the long-term evolution of the whole west Antarctic ice
sheet,” the authors said in the Proceedings of the National Academy of Sciences.
They used computer models to project the effects of 60 more years of melting at the current rate.
This “would drive the west Antarctic ice sheet past a critical threshold beyond which a complete, long-term disintegration would occur.”
In other words, “the entire marine ice sheet will discharge into the ocean, causing a global sea level rise of about three meters,” the authors wrote.
“If the destabilisation has begun, a three-meter increase in sea level over the next several centuries to millennia may be unavoidable.”
Even just a few decades of ocean warming can unleash a melting spree that lasts for hundreds to thousands of years.
http://www.theguardian.com/world/2015/nov/02/melting-ice-in-west-antarctica-could-raise-seas-by-3m-warns-study
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