The Greenland ice sheet may disappear permanently at a much lower global temperature increase than previously thought, according to research recently published in Nature and Climate Change. Researchers have modelled how the ice melts during a longer period of warming and found that the threshold for an ice-free Greenland is in the range of 0.8 to 3.2°C with 1.6°C as the most likely figure, which is 1.5°C less than previous estimates.
“The more we exceed the threshold, the faster it melts,” says Alexander Robinson, lead author of the study.
The research also shows that the melting under certain conditions is irreversible and a so-called tipping point in the Earth system.
Andrey Ganopolski, team leader for the research group, commented: “If the global temperature significantly overshoots the threshold for a long time, the ice will continue melting and not regrow – even if the climate would, after many thousand years, return to its preindustrial state.”