Ice melting from glaciers around the world is depleting regional freshwater resources, and also driving global sea levels to rise at ever-faster rates.
According to new findings through an international research effort involving 35 research teams, The Glacier Mass Balance Intercomparison Exercise (GlamBIE), glaciers have been losing an average of 273 billion tonnes of ice per year since the year 2000 – but hidden within this average there is an alarming increase over the last 10 years. The study was co-ordinated by the World Glacier Monitoring Service and hosted at the University of Zurich (UZH).
Norwegian researchers, including Désirée Treichler, Dept. of Geosciences at the University of Oslo, participated in this extensive study. Treichler contributed glacier data for four regions: Iceland, and three high mountain regions in Asia, and served as an expert for two of the four methods used in the study.
The new research of loss of ice mass from land based glaciers is published in the scientific journal Nature.
Use of satellites to compare glacier mass changes
This new research of ice mass of the glaciers over the whole world is notable for using satellite data analyzed with digital surface elevation model (DEM) time series, altimetry, gravimetry and field measurements, providing actual data series based on satellite observations rather than modelled data from glacier and climate models.
– The timeseries compiled from satellite data give us a precise overview of the mass balance of the glaciers worldwide. The satellites measure even the most remote areas, and provide a complete picture of the status of glaciers. We used four complementary data sources to measure recent changes in their ice volume, and corresponding fresh water loss on a global scale. The new timeseries are interesting for climate research, and also for the IPCC assessments of climate change, says Désirée Treichler, researcher on geomatics and the cryosphere.
The GlaMBIE-research exercise saw hundreds of contributors from around the world. The study combined different types of data from field measurements and gained from satellite sensors including optical, radar, laser and gravimetry satellite missions to compile timeseries of glacier mass change for all glacier regions globally from 2000 to 2023.
Glacier melt intensifying freshwater loss and accelerating sea-level rise
The researchers in the team found in the study that, since 2010, glaciers have lost approximately five per cent of their total volume, with central Europe losing a staggering 39 per cent while areas like the Antarctic and Subantarctic Islands lost about two per cent.
They also found that the amount of ice lost was 36 per cent greater between 2012 and 2023 compared to the 231 billion tonnes lost in the first half of the study period.
In addition to the rising sea levels, glacier melt represents a significant loss of regional freshwater resources. Professor and Glaciologist Michael Zemp, University of Zurich, who co-led the study, explains this with an example more easy to understand:
– To put this in perspective, the 273 billion tonnes of ice lost annually amounts to what the entire global population consumes in 30 years, assuming three litres per person and day, noted glaciologist Prof. Zemp.
Glacier mass loss between 2000 and 2023 was 18 per cent higher than that of the Greenland ice sheet and more than double that from the Antarctic ice sheet. Researchers warned that aside from contributing to the rising of global sea levels, the glacier melt will deplete the freshwater reserves.
GlaMBIE 2 and studies of regional differences
This new study done required several years of work, analyses, and discussions between the GlaMBIE-network. The satellite observations included – among others – those from the US Terra/ASTER and ICESat-2, the US–German GRACE, the German TanDEM-X and the European Space Agency/ESA’s CryoSat missions.
Since such a controlled data foundation has not been available until now, IPCC reports have been based on model calculations and selected regional/global studies.
– But it is reassuring (for us and for the IPCC/models) that the 'final sum' we derive from the data aligns with the IPCC's figures, says Treichler.
– However, there are regional differences to the modelled results that would be useful to examine more closely, and there is room for follow-up studies that go into even greater detail and include estimates from more research groups. Therefore, we hope to start with GlaMBIE 2 later this year, concludes Désirée Treichler, specialist in the use of geomatics to monitor the cryosphere, in particular snow, ice and glaciers on land.
The scientific article:
The GlaMBIE Team. Community estimate of global glacier mass changes from 2000 to 2023. Nature (2025). https://doi.org/10.1038/s41586-024-08545-z
Read more about the GlaMBIE research exercise