Melting glaciers accelerate sea level rise and put drinking water supply at risk

All relatively small glaciers combined (because those of Antarctica and Greenland are not included) lost approximately 5% of their volume between 2000 and 2023. This amounts to a loss of 273 billion tonnes of ice, which is more than double that of the Antarctica Ice Sheet. In Central Europe, think of the Alps, even 39% of the ice mass was lost.

Intensifying loss
Unsurprisingly, the amount of meltwater coming down varies per year. But the pattern that is becoming visible the researchers call shocking. Between 2012 and 2023, much more ice was lost (36% more meltwater) compared to the decade before.

It is not only about rising sea levels, says Bert Wouters. “We will directly notice the melting of these glaciers. Because they are located where many people live, it will affect drinking water supplies, in particular in South America and Asia. And the risk of flooding after the melt season also poses a danger.”

Combining global melt data
Bert Wouters is Associate Professor of Geoscience and Remote Sensing at TU Delft and ensured that the data from many studies together produced a solid estimate. “From the accessible glaciers, we have lots of field measurements. From all those other glaciers, we have data from satellites. The methods and thus the meltwater estimates were often varying. It was a big challenge to make it scientifically unified.”

The team of researchers, part of the Glacier Mass Balance Intercomparison Exercise (Glambie), succeeded. This resulted in an annual time series of glacier mass changes for all glacier regions globally from 2000 to 2023.