PARIS: The melting of Greenland´s massive ice sheet is happening much faster than expected and could put millions more people at risk by the end of the century, scientists warned Tuesday.
Up to three kilometres thick in some places, Greenland has lost 3.8 trillion tonnes of ice since 1992, enough on its own to add 10.6 millimetres (1.06 centimetres, 0.4 inches) to sea levels, according to a study in the journal Nature.
It showed that the rate of ice loss has risen from an average 33 billion tonnes per year in the 1990s to 254 billion tonnes in just three decades. Many scientists fear that global warming driven by greenhouse gas emissions have pushed the ice sheets to a point of no return, with potentially catastrophic consequences for mankind.
The Intergovernmental Panel on Climate Change (IPCC) in 2013 gave a central forecast that if global warming continued, sea levels would rise 60 centimetres by 2100, putting 360 million people at risk of annual coastal flooding. The latest study however shows that Greenland´s faster-than-expected ice losses are in line with the IPCC´s higher-end climate warming scenario which adds seven centimetres to that figure. "As a rule of thumb, for every centimetre rise in global sea level another six million people are exposed to coastal flooding around the planet," said co-author Professor Andrew Shepherd of Leeds University in the UK.
"On current trends, Greenland ice melting (alone) 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 rise," Shepherd said. "These are not unlikely events or small impacts; they are happening and will be devastating for coastal communities," he added.
Dr Louise Sime, a climate scientist at the British Antarctic Survey, said the findings "should be of huge concern for all those who will be affected by sea level rise." "If this very high rate of ice loss continues, it is possible that new tipping points may be breached sooner than we previously thought," Sime added.