Greenland is losing ice seven times faster than in the 1990s and is tracking the IPCC’s high-end climate warming scenario, which would see 40 million more people exposed to coastal flooding by 2100. The findings, published in Nature today, show that Greenland has lost 3.8 trillion tonnes of ice since 1992 – enough to push global sea levels up by 10.6 millimetres. The rate of ice loss has risen from 33 billion tonnes per year in the 1990’s to 254 billion tonnes per year in the last decade – a seven-fold increase within three decades.
A team of 89 polar scientists from 50 international organisations have produced the most complete picture of Greenland ice loss to date. The Ice Sheet Mass Balance Inter-comparison Exercise (IMBIE) Team combined 26 separate surveys to compute changes in the mass of Greenland’s ice sheet between 1992 and 2018. Altogether, data from 11 different satellite missions were used, including measurements of the ice sheet’s changing volume, flow and gravity. Utrecht University researchers contributed by accurately calculating the amount of snowfall and meltwater runoff over the Greenland ice sheet. Increased meltwater runoff is the major source of mass loss from the ice sheet.