Greenland’s ice sheet could melt at much lower temperatures than previously thought, according t a new study published in the Journal of Nature Climate Change. The lives of millions of people could be threatened if the melting of land ice raises sea levels by several metres as predicted.
“Our study shows that a temperature threshold for melting [the ice sheet] exists, and that this threshold has been overestimated until now,” said scientists at the Potsdam Institute for Climate Impact Research and the Universidad Complutense de Madrid.
The team made predictions about the future behaviour of the ice sheet by using computer simulations. According to the scientists, the ice sheet could completely melt if global temperatures rise by between 0.8 and 3.2 degrees Celsius, despite previous research suggesting the ice would only be affected within the range of 1.9 to 5.1 degrees.
Greenland, which has a tenth of the world’s ice, is currently 80 percent frozen. According to previous research, global sea levels could rise by as much as 6.4 metres if the entire ice sheet melted.
“If the global temperature significantly overshoots the threshold for a long time, the ice will continue melting and not re-grow, even if the climate would, after many thousand years, return to its pre-industrial state,” team leader Andrey Ganopolski told Reuters at the Potsdam Institute for Climate Impact Research.
“The more we exceed the threshold, the faster it melts,” added Alexander Robinson, lead-author of the study. “If the world takes no action to limit greenhouse gas emissions, the earth could warm by eight degrees Celsius. This would result in one fifth of the ice sheet melting within 500 years and a complete loss in 2,000 years,” he said.