Greenland and Antarctica Lose 12.5 Trillion Tons of Ice Since 1979, Study Finds

Since 1979, the ice sheets of Greenland and Antarctica have lost 12.5 trillion tons of mass. Data published in Scientific Data, based on satellite archives from NASA and the European Space Agency, reveals a stark discrepancy between the perceived drivers of melting and the actual physical mechanisms at work. The central tension in the data lies in the role of the ocean versus the atmosphere. While rising air temperatures often dominate the public narrative, the study shows that atmospheric warming is a secondary factor. Five-sixths of the ice loss is driven by warm oceanic currents eroding the sheets from below and the sides. This basal melting destabilizes the ice, accelerating the flow of glaciers into the sea. In Greenland, the Jakobshavn glacier exemplifies this speed, retreating by up to 50 meters per day. This loss of 11.3 quadrillion liters of water has already raised global sea levels by 3.1 cm. The human cost of this measurement is significant: Ines Otosaki from Northumbria University notes that every 0.8 cm of sea-level rise correlates with the flooding of areas inhabited by 2 to 3 million people.