The Greenland ice sheet is melting seven times faster than it was nearly three decades ago, according to a study.
The ice loss has resulted in global sea levels rising by around 10.6mm since 1992, the scientists added.
If the loss continues at the current rate around 400 million people will be exposed to coastal flooding each year by the end of the century - 40 million more than the number predicted by the Intergovernmental Panel on Climate Change (IPPC).
A group of 96 polar scientists from around the world have published their study of the world's second largest body of ice in Nature magazine.
It provides the most complete picture available to date of what is happening there.
They found that Greenland has lost 3.8 trillion tonnes of ice since 1992.
And the rate of ice loss is speeding up too, from 33 billion tonnes per year in the 1990s to 254 billion tonnes per year at the moment.
That represents a seven-fold increase within the last three decades
Lead author professor Andrew Shepherd said: "As a rule of thumb, for every centimetre rise in global sea levels another six million people are exposed to coastal flooding around the planet.
"On current trends, Greenland ice melting will cause 100 million people to be flooded each year by the end of the century, so 400 million in total due to all sea level rises.
"These are not unlikely events or small impacts, they are happening and will be devastating for coastal communities."
The alarming predictions come even as the scientists' study showed that the rate of ice loss slowed between 2013 to 2017.
This coincided with a period of cooler oceans and atmospheric temperatures.
But scientists warn that no matter what steps we take to limit global warming now, the slow process of melting ice will continue for decades to come.
Source: Sky News