Loss of a crucial 'plug' of ice in Antarctica could result in massive sea-level rise, with the discharge of a huge ice sheet.

The Wilkes Basin in East Antarctica contains enough ice to raise global sea levels by 3–4 metres. Anders Levermann and Matthias Mengel at the Potsdam Institute for Climate Impact Research in Germany used topographic data and simulations of ice dynamics to investigate the basin's vulnerability to climate change. They found that if a key plug of ice — equivalent to 80 millimetres of global sea-level rise — were to be lost from the region, the Wilkes Basin ice sheet would be destabilized, creating a self-sustaining discharge of the whole basin over 10,000 years and leading eventually to global sea-level rise on the metre scale.

However, the ice sheet would remain stable if the equivalent of less than 60 millimetres of sea-level rise were lost.

Nature Clim. Change http://dx.doi.org/10.1038/nclimate2226 (2014)