Prof Bamber said: “Five degrees warming by 2100 is a pretty awful scenario, you just don’t want to think about the consequences of that for the whole planet.
“It would mean that we as a species and many parts of the Earth’s systems would be under serious threat.”
He added a two-metre rise in global sea levels “could result in land loss of 1.79 million km2, including critical regions of food production, and potential displacement of up to 187 million people.”
However, scientists found that if actions reach emissions targets set by the Paris climate agreement, temperatures would rise by 2C, causing close to 10 inches (26cm) sea level rise by the end of the century.
But coastal communities should not rule out the possibility of higher sea level rise by the 21st century.
UK underwater MAPPED: The areas of the UK that will disappear if the ice caps melt – Express