This article has been reviewed according to Science X's editorial process and policies. Editors have highlighted the following attributes while ensuring the content's credibility: The longest satellite record ever assembled shows that Greenland and Antarctica have lost 11.3 trillion metric tons of ice since the 1970s, raising global sea level by more than 3 centimeters (1.2 inches)—and that most of the loss has come from glaciers flowing faster into the ocean, not from melting at the surface. An international team of polar scientists has produced the most complete picture of ice loss from Greenland and Antarctica to date.
The Ice Sheet Mass Balance Inter-comparison Exercise (IMBIE) Team combined 42 independent satellite surveys, drawing on 27 satellite missions and reaching back to 1972 for Greenland and 1979 for Antarctica using the early Landsat archive. The findings show the two ice sheets lost 11,309 billion metric tons of ice between 1979 and 2023, pushing global sea level up by 31.4 millimeters (1.2 inches). Greenland accounted for the larger share, and Antarctica contributed 13.3 millimeters (0.5 inches).
Strikingly, 84% of the combined loss was driven by glaciers speeding up and pouring more ice into the ocean, with just 16% due to surface melting. The polar ice sheets are now responsible for around a quarter of all global sea level rise. The assessment was led by Dr.
Inès Otosaka and Professor Andrew Shepherd at Northumbria University, and Dr. Tyler Sutterley of the University of Washington Applied Physics Laboratory. It is supported by the European Space Agency (ESA) and the U.S.
National Aeronautics and Space Administration (NASA) and is published in the journal Scientific Data. Otosaka, who led the study, said, "By reaching back to the 1970s, we can now see how the ice sheets have changed across half a century. More than four-fifths of the ice lost was discharged into the ocean by faster-flowing glaciers, rather than melted at the surface—which tells us the long-term trend is being driven by the dynamic response of the ice sheets to a warming ocean." The record shows ice losses climbing steeply from the 1990s onward.
Greenland, close to balance in the 1970s, saw its rate of loss rise from around 60 billion metric tons a year in the 1980s to 264 billion metric tons in the 2010s, a decade marked by repeated extreme summer melt events. Antarctica's rate rose from around 48 billion metric tons a year in the 1980s to 202 billion metric tons in the 2010s, with all of its net loss caused by ocean melting of its outlet glaciers. West Antarctica's ice discharge, led by Pine Island and Thwaites glaciers, has risen in every decade of the record.
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