Polar ice sheets lost 11.3 trillion tonnes since 1979, study finds

Greenland and Antarctica lost a combined 11.3 trillion metric tonnes of ice between 1979 and 2023, contributing approximately 3.2 centimetres to global sea level rise, according to a major international scientific study. The research, published in the journal Scientific Data, provides the most comprehensive account to date of polar ice sheet changes, drawing on data from 27 satellite missions. The study found that about 84% of the ice loss was caused by glaciers accelerating and discharging ice into the ocean, while surface melting accounted for the remaining 16%. This indicates the long-term trend is primarily driven by the dynamic response of the ice sheets to a warming ocean, rather than warmer air temperatures alone. Ice loss accelerated sharply from the 1990s, with the pace increasing by a factor of four between the 1980s and 2010s. The data shows the ice sheets were relatively stable through the 1970s and 1980s before losses began to mount. Greenland accounted for about 60% of the total loss, despite being roughly one-eighth the size of Antarctica. Researchers noted a temporary slowdown in ice loss between 2020 and 2023.