"Roughly the size of France"
A glacier in East Antarctica is eroding underneath due to impending climate change.
The Totten Glacier is feared to endanger coastal communities. Calculations show that it will contribute a two-meter rise in sea level.
Its underbelly is being eroded by warm sea water.
With the increasing global temperature caused by greenhouse gases that warm the atmosphere, the ice caps will continue to melt and oceans will rise.
"I predict that before the end of the century, the great global cities of our planet near the sea will have two- or three-metre high sea defences all around them," said Martin Siegert, co-director of the Grantham Institute and Department of Earth Science and Engineering at Imperial College London, and the study's senior author.
In the illustration, the deep warm ocean water penetrates the glacier from below.
This reduces the ice resting on the rockbed, therefore making it easier for the warm water to enter the glacier.
The melting ice above will break away to the sea, and the melting ice underneath will accumulate, causing the warm water to rapidly.
Dr. Aitken, the study's co-author, said that this scenario could be avoided if global warming could be limted to two degrees.
In the Paris Climate Agreement last December 2015, 195 countries pledged to cut their carbon emissions and reliance on fossil fuels.
Scientists said that even with a 2 celsius cap, the effects of climate change would still be fatal to affected countries.
Countries took steps in transitioning from coal power to renewable energy sources.
With the help of rich countries, the underdeveloped and developing nations will be able to participate in the adaptation plans.
The Paris Climate Agreement will take effect in 2020.