The dramatic retreat observed recently in Greenland’s outlet glaciers could be a transient response to climatic changes, suggests a study online in Nature Geoscience. Recent increases in the rates of mass loss from Greenland should therefore not be extrapolated into the future.

Faezeh Nick, Andreas Vieli and colleagues present a numerical ice-flow model that reproduces the retreat, thinning and acceleration of Helheim Glacier, Greenland. Their results suggest that Greenland’s outlet glaciers are very sensitive to changes at their seaward end, and adjust extremely rapidly.

Such a mechanism could explain the synchronous behaviour of several Greenland glaciers in response to climatic changes, and implies that the observed loss from Greenland glaciers does not provide a reliable measure for the longer-term mass balance of the ice sheet.