Above all, the researchers examined the changes at the so-called snow line of the ice sheet: where there is snow on the ice in summer that reflects sunlight well, the ice is in equilibrium. Conversely, where the bare ice can be seen, which appears much darker, the summer melt is greater than the snow gain in winter, and the ice is imbalanced. In addition, the ice is not melting evenly across the surface, but mainly along the edges in the warmer lower layers.
A disadvantage of this method, however, is that it does not specify a time frame for the developments. “In order to get the numbers we determined, we had to ignore the time factor in the calculation,” Box said, according to a GEUS statement. “But our observations suggest that most of the expected sea-level rise will occur within this century.”
However, the 27 centimeters by which sea level will definitely rise is only a minimal assumption. “Realistically, that number will more than double this century,” Box said. “In the foreseeable scenario that global warming will continue, the Greenland ice sheet’s contribution to sea level rise will continue to increase.” had the highest melt rate recorded to date, and assumed that these conditions would persist year after year. In this case, the melting of the Greenland ice sheet would result in a sea level rise of more than 78 centimeters.