The Greenland ice sheet is losing its mass faster than in previous years and making an increasing contribution to sea level rise, a study has confirmed. Published in the journal Science, it has also given scientists a clearer view of why the sheet is shrinking. The team used weather data, satellite readings and models of ice sheet behaviour to analyse the annual loss of 273 thousand million tonnes of ice. Melting of the entire sheet would raise sea levels globally by about 7m (20ft). For the period 2000-2008, melting Greenland ice raised sea levels by an average of about 0.46mm per year. If you multiply these numbers up it puts us well beyond the IPCC estimates for 2100. Since 2006, that has increased to 0.75mm per year. "Since 2000, there's clearly been an accelerating loss of mass [from the ice sheet]," said lead researcher Michiel van den Broeke from Utrecht University in the Netherlands. "But we've had three very warm summers, and that's enhanced the melt considerably. BBC NEWS | Science & Environment | Greenland ice loss 'accelerating'