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.
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The group's findings agree remarkably well with a study released earlier this year that used data from other satellites to estimate mass changes in the Greenland ice. Grace also appears to have detected a loss of ice from Arctic glaciers that were omitted from this study and are separate from the main Greenland ice sheet.
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http://news.bbc.co.uk/2/hi/science/nature/4783199.stm