Cumulative changes in the mass of the Antarctic ice sheet (pink) and the Greenland ice sheet (blue) from 1992 to 2011 determined from a reconciliation of measurements acquired by satellite radar altimetry, the input-output method, satellite gravimetry and satellite laser altimetry. Also shown is the equivalent global sea level contribution, calculated assuming that 360 gigatonnes of ice corresponds to 1 mm of sea level rise.