J. Glaciol. http://doi.org/b5hr (2017)

Mass loss from the Greenland ice sheet is a major source of global sea-level rise. Approximately half of Greenland's present-day contribution comes from dynamical ice loss — enhanced discharge from calving glaciers — but future changes in these processes remain poorly constrained.

Daniele Peano from Ca' Foscari University and the Euro-Mediterranean Centre on Climate Change, Italy, and co-authors investigate the evolution of ice dynamics at five of the fastest-flowing regions in Greenland: the Petermann, Kangerdlugssuaq, Helheim, and Jakobshavn glaciers, and the North-East Greenland Ice Stream. They use a hybrid ice-sheet model forced with output from seven CMIP5 models.

At all locations except the Kangerdlugssuaq glacier, the authors report a projected ice-flux reduction up to 2100, that is, a decrease in the volume of ice reaching the coast. These changes are attributed to a climate-related shift toward negative surface mass balance, wherein greater summertime melt compared to wintertime snow accumulation reduces glacial thickness, decreasing the ice available for calving. In most fast-flowing regions dynamical ice loss becomes decreasingly important, emphasising the need to reduce meltwater uncertainties for improved sea-level rise projections.