Greenland and Antarctica lost 11.3 trillion tonnes of ice since 1979, raising sea levels by 3.14 cm

Comprehensive satellite records

A study published in Scientific Data by the Ice Sheet Mass Balance Intercomparison Exercise (IMBIE) shows that Greenland and Antarctica lost 11.3 trillion tonnes of ice between 1979 and 2023. Supported by the European Space Agency and NASA, polar researchers combined 42 independent surveys drawing on 27 satellite missions, including CryoSat, Copernicus Sentinel, GRACE, and early Landsat records. The dataset spans from 1972 for Greenland and 1979 for Antarctica. This total ice loss caused global sea levels to rise by 3.14 centimetres over the evaluated period. Greenland accounted for 1.81 centimetres of the increase, while Antarctica added 1.33 centimetres. Together, the two ice sheets generate roughly one quarter of global sea level rise, with mountain glacier melt and seawater thermal expansion accounting for the remaining three quarters.

Acceleration across four decades

The pace of polar ice depletion accelerated after 1990. During the 1980s, Greenland lost an average of 60 billion tonnes of ice annually, a rate that climbed to 264 billion tonnes per year during the 2010s. Antarctica exhibited a similar pattern, increasing from an average annual loss of 48 billion tonnes in the 1980s to 202 billion tonnes per year in the 2010s. The Jakobshavn glacier in Greenland now retreats at speeds of up to 50 metres per day. Lead author Ines Otosaka explained the sustained decadal trajectory of polar ice sheet drainage.

There is a clear trend that the ice sheets are losing more and more mass, and this has increased from one decade to the next, especially if we look at the ice discharged into the ocean.

Ocean warming as the primary driver

Dynamic glacier acceleration, rather than surface melting from warm air, caused 84% of the combined ice loss across both regions. In Antarctica, the entire loss resulted from accelerated glacier flow and underwater erosion by warming ocean waters. Only 16% of the total polar ice loss was caused by surface melting. Otosaka noted the specific mechanism steering the long-term ice sheet retreat.

More than four fifths of the ice loss was discharged into the ocean by faster-flowing glaciers and did not melt on the surface.

Human impact and short-term variations

Even modest changes in ocean height alter coastal exposure across the globe. Researchers calculate that every additional centimetre of sea level rise places another two to three million people at risk of annual coastal flooding. The cumulative 3.14-centimetre rise documented by the team places six to nine million additional people in flood and erosion zones. Andrew Shepherd, founder of IMBIE, described the immediate consequences for vulnerable communities.

A sea level rise of just over three centimetres may sound small, but it exposes six to nine million additional people to coastal flooding and erosion.

Between 2020 and 2023, the rate of ice loss slowed temporarily due to specific meteorological conditions. Heavy snowfall in East Antarctica compensated for glacier losses in other parts of the continent, while a sequence of milder summers halved surface melting in Greenland. The authors stated that these short-term variations do not reverse the multi-decade pattern of glacier retreat.