Greenland Ice melt 'speeding up'

Break-off point into the ocean of Helheim Glacier in southeast Greenland. The meltdown of Greenland's ice sheet is speeding up, satellite measurements show. Data from a US space agency (Nasa) satellite show that the melting rate has accelerated since 2004. If the ice cap were to completely disappear, global sea levels would rise by 6.5m (21 feet). Most of the ice is being lost from eastern Greenland, a US team writes in Science journal. Jianli Chen of the University of Texas at Austin and colleagues studied monthly changes in the Earth's gravity between April 2002 and November 2005. These measurements came from the US space agency's Grace (Gravity Recovery and Climate Experiment) satellite, launched in 2002. "Acceleration of mass loss over Greenland, if confirmed, would be consistent with proposed increased global warming in recent years." Estimated monthly changes in the mass of Greenland's ice sheet suggest it is melting at a rate of about 239 cubic kilometres (57.3 cubic miles) per year. This figure is about three times higher than an earlier estimate of the mass loss from Greenland made using the first two years of Grace measurements.