Earth’s Ice Sheets Lost 11.3 Trillion Tonnes of Ice in Four Decades, Study Finds

Earth’s two major ice sheets have lost an estimated 11.3 trillion metric tonnes of ice over a period of more than four decades, contributing significantly to rising global sea levels, according to a new study based on satellite observations.

The research examined changes in the Greenland and Antarctic ice sheets between 1979 and 2023. Scientists combined observations from 27 satellite missions with data from 42 independent surveys to build one of the most comprehensive long-term records of polar ice loss.

The study found that the combined loss of ice from Greenland and Antarctica contributed approximately 3.1 centimetres to global sea-level rise during the period. Researchers said the findings provide important evidence of how the world’s major ice sheets are responding to changes in climate and atmospheric conditions.

A significant proportion of the loss was linked to glaciers accelerating and moving larger quantities of ice into the surrounding oceans. According to the research, around 84 per cent of the ice loss was associated with this process, while the remaining loss came from changes occurring at the surface of the ice sheets.

The rate of ice loss also increased substantially over the decades covered by the study. Scientists observed particularly pronounced changes from the 1990s through the 2010s, indicating that the contribution of the polar ice sheets to sea-level rise has become increasingly important.

However, the researchers noted that ice loss did not increase continuously every year. Between 2020 and 2023, the rate temporarily slowed, partly because of short-term weather patterns and increased snowfall in some areas of Antarctica. Scientists cautioned that this period does not represent a reversal of the longer-term trend.