From Alaska to the Pyrenees, glaciers are shrinking at an unprecedented rate. This melting, now measured with great precision, is disrupting hydrological balances and directly contributing to rising sea levels. A set of data compiled between 2000 and 2023 by international teams confirms the global melting of terrestrial glaciers and paints a picture of a future where water will be a precious resource.
by Laurie Henry
As pillars of the water cycle, terrestrial glaciers are important water reservoirs and play a role in regulating our planet’s climate. Their melt feeds rivers in summer, stabilises mountain ecosystems and contributes to global sea level rise.
Today, their rapid decline is no longer a hypothesis but a quantified reality. A recent international study provides an unprecedented assessment of their evolution over nearly a quarter of a century. Coordinated by the GlaMBIE consortium (for Glacier Mass Balance Intercomparison Exercise), this synthesis involved 35 research teams from 19 glacial regions, including French scientists from the CNRS and LEGOS in Toulouse.
The results are clear: between 2000 and 2023, glaciers outside the polar ice caps lost 5% of their volume, with a marked acceleration in recent years. This finding sheds light on many immediate issues such as water resources, coastal zone management and the associated socio-economic impacts.
Cross-referenced measurements for a reliable overall view
For a long time, scientists lacked consistent, comprehensive data to assess glacier melt. Each method provided fragmented information: field measurements, limited to a few hundred accessible glaciers, did not reflect global diversity; satellite images, accurate but scattered, produced results that were difficult to compare. For the first time, the GlaMBIE consortium, coordinated by the World Glacier Monitoring Service in Zurich with support from the University of Edinburgh, has brought together all of these approaches and enabled nearly 450 researchers to harmonise 233 sets of measurements.