Glaciers, Water, and a Decade of Action

​This weekend brings together three closely connected moments: International Glacier Day, World Water Day, and the start of the UN Decade of Action for Cryospheric Sciences. Together, they highlight a simple reality in mountain regions: ice, water, and climate are tightly linked and changing quickly.
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Glaciers support water resources, shape access in mountain terrain, and are part of the culture and identity of many regions. They are also rapidly retreating in ways that are easy to grasp. We can look at photographs from 20, 10, or even just a few years ago and see how much alpine landscapes have changed as glaciers recede to higher elevations. Recent global studies show that nearly all glaciers on Earth have changed over the past decades (Dussaillant et al., 2024), with accelerating losses in recent years (Menounos et al., 2025, Hugonnet et al., 2021). This change can be measured and tracked, showing how quickly conditions are shifting as temperatures rise.

One of the key consequences of this change is how it affects water downstream, in ways that are far less visible than glacier retreat itself. As glaciers shrink, the storage, timing, and pathways of water through mountain systems are shifting. This is changing when water is available, how much is available, and increasing pressure during low-flow periods. The close succession of Glacier Day and World Water Day reflects this fundamental connection.

In response to these changes, the UN Decade of Action for Cryospheric Sciences (2025–2034) has been launched as a global initiative to advance research and support informed action. It calls on scientists, governments, and communities to work together to better understand the cryosphere and to safeguard the billions of people who depend on it.
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At the Mountain Ice and Water Lab, we work to better understand how these changes are reshaping mountain water systems. Over the coming years, we’ll continue building the knowledge needed to make sense of a rapidly changing water cycle. This includes starting new projects in the Canadian Rockies to investigate these linkages, continuing and building new collaborations, training and recruiting students, expanding fieldwork, and using hydrological modelling to better understand ongoing changes, while ensuring our work helps address some of the most pressing water challenges facing society. We’re looking forward to the work ahead and to sharing what we learn along the way.
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More information:

The UN Decade of Cryospheric Action:  https://www.un-cryosphere.org/en

Hugonnet, R., McNabb, R., Berthier, E., Menounos, B., Nuth, C., Girod, L., Farinotti, D., Huss, M., Dussaillant, I., Brun, F., & Kääb, A. (2021). Accelerated global glacier mass loss in the early twenty-first century. Nature, 592(7856), 726–731.
DOI: 10.1038/s41586-021-03436-z

Dussaillant, I., Hugonnet, R., Huss, M., Berthier, E., Bannwart, J., Paul, F., & Zemp, M. (2025). Annual mass change of the world's glaciers from 1976 to 2024 by temporal downscaling of satellite data with in situ observations. Earth System Science Data, 17, 1977–2006.
DOI: 10.5194/essd-17-1977-2025
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Menounos, B., Huss, M., Marshall, S., Ednie, M., Florentine, C., & Hartl, L. (2025). Glaciers in Western Canada–conterminous US and Switzerland experience unprecedented mass loss over the last four years (2021–2024). Geophysical Research Letters, 52, e2025GL115235.
DOI: 10.1029/2025GL115235