Polar Ice Sheets Lose 11.3 Trillion Tons

A comprehensive assessment of satellite observations found that Greenland and Antarctica lost about 11.3 trillion metric tons of ice between 1979 and 2023, raising global average sea levels by roughly 3 centimeters and contributing about one-quarter of recent sea-level rise. More than four-fifths of the loss came from glaciers accelerating into the ocean, rather than from surface melting alone, as relatively warm seawater eroded ice shelves and weakened the glaciers’ grounding points. Greenland accounted for about 6,500 billion tons of the loss, while Antarctica contributed roughly 4,780 billion tons, with West Antarctic outlet glaciers playing a major role. Ice loss accelerated substantially during the 2010s, and researchers say the trend could continue for decades because the ice sheets respond slowly to climate warming. Although geothermal heat, including a mantle plume beneath Antarctica’s Marie Byrd Land, affects local conditions, scientists say it is a long-term background factor rather than the primary cause of the recent polar decline.