Greenland and Antarctica have lost 12 trillion tonnes of ice since 1979

Ice loss began accelerating in the 1990s, according to a major scientific study. Greenland and Antarctica have lost 12.5 trillion tonnes of ice since 1979, raising global sea levels by around 3.2 centimetres, according to a major scientific study. The researchers found that ice loss has accelerated in recent decades, particularly since the 1990s. Most of the loss is linked to warmer ocean temperatures, which cause glaciers to discharge more ice into the sea. Ice loss accelerated sharply during the 2010s The study combines satellite observations covering more than four decades. It extends the record back to 1979 for Antarctica and 1972 for Greenland. The data shows the ice sheets were relatively stable through the 1970s, 1980s and into the 1990s. Ice loss then increased, with the strongest acceleration recorded during the 2010s. “There is a clear trend that the ice sheets are losing more mass and it has been increasing from decade to decade,” says Inès Otosaka, an ice scientist at Northumbria University. She says the changes were clearly linked to rising air and ocean temperatures. Warmer oceans drive most of the ice loss Around 84 per cent of the ice loss is linked to increased ice discharge into the oceans, the researchers found. Surface processes account for the remaining 16 per cent. Warmer seawater can erode ice from below and around the edges of glaciers, increasing their flow towards the ocean. In Greenland, the Jakobshavn glacier is retreating by up to 50 metres a day, Otosaka says. Ice loss is raising sea levels The ice loss has contributed around 3.2 centimetres to global sea level rise since 1979. Scientists say even small increases can have significant consequences for coastal areas. For every centimetre of sea level rise, an estimated two to three million more people could face annual coastal flooding. Ice loss slowed between 2020 and 2023, but researchers say this reflected short-term weather patterns rather than a change in the longer-term trend. They also warn that ice-sheet responses to climate change can take decades. This means ice loss could continue even if global warming were brought under control. The study was published in the journal Scientific Data.