Mountains are key to water supply, says report

Mountains are an essential source and a central reservoir for fresh water worldwide. "Water from the high mountains and in particular from glaciers is extremely important, especially during dry and hot phases," said Swiss glaciologist Matthias Huss to the Science Media Center (SMC).

According to Huss, glaciers melt particularly strongly during periods of drought and can thus fill a gap in the water supply. But only as long as they are still a certain size. Huss is head of the Swiss glacier monitoring network Glamos.

The contribution of glaciers to runoff is decreasing in the long term, which could lead to water shortages in dry regions such as Central Asia, added Samuel Nussbaumer from the World Glacier Monitoring Service (WGMS) at the University of Zurich. "Springs fed by glacier water are also drying up in the Alps, which can become a problem for mountain huts," continued Nussbaumer.

New reservoirs as water storage

In some places, the storage effect of glaciers could be artificially replaced by new reservoirs, said Huss. Glacier researchers from Germany and Austria also suggested the construction of new reservoirs to the SMC as an adaptation strategy.

"After the retreat of the glacier tongues, new areas are created, often lifeless scree deserts, where such reservoirs could be created. This would enable better management of scarce water resources." However, Huss emphasized that nature and landscape conservation must be carefully weighed up against such projects.

The World Water Report of the United Nations Educational, Scientific and Cultural Organization (Unesco), which was first published in 2003, has been published annually since 2014 and is dedicated to a specific topic, this year highlighting the role of mountains as the Earth's "water castles". The publication date coincides with World Glacier Day, which is being celebrated for the first time.