Between 2011 and 2014, Greenland lost around one trillion tonnes of ice. This corresponds to a 0.75 mm contribution to global sea-level rise each year – about twice the average of the preceding two decades. These results from the UK Centre for Polar Observation and Modelling (CPOM) at the University of Leeds combine data from the CryoSat mission with a regional climate model to map changes in Greenland ice-sheet mass.