Glaciers Demise is Security Nightmare

For most people those before/after pictures of melting glaciers might evoke some kind of “oh, that’s sad, glaciers are pretty” reaction.
But for the glacier experts I’ve spoken to over the years, there is a much more urgent message. Glaciers perform a critical function of storing and slowly releasing water in strategically significant areas of the world.

In Asia, billions of people, whose governments have been historically at odds, and are now nuclear armed, rely on Himalayan glaciers as primary water sources for drinking, agriculture and industry. The rapid decay of these reservoirs should give us all pause.
Lonnie Thompson and the late Konrad Steffen have been among the most deeply informed scientists on these issues.

Reuters:

Glaciers around the globe are disappearing faster than ever, with the last three-year period seeing the largest glacial mass loss on record, according to a UNESCO report, opens new tab released on Friday.

The 9,000 gigatons of ice lost from glaciers since 1975 are roughly equivalent to “an ice block the size of Germany with the thickness of 25 meters,” Michael Zemp, director of the Switzerland-based World Glacier Monitoring Service, said during a press conference announcing the report at the UN headquarters in Geneva.

The dramatic ice loss, from the Arctic to the Alps, from South America to the Tibetan Plateau, opens new tab, is expected to accelerate as climate change, caused by the burning of fossil fuels, pushes global temperatures higher. This would likely exacerbate economic, environmental and social problems across the world as sea levels rise and these key water sources dwindle.

The report coincides with a UNESCO summit in Paris marking the first World Day for Glaciers, urging global action to protect glaciers around the world.

Zemp said that five of the last six years registered the largest losses, with glaciers losing 450 gigatons of mass in 2024 alone.

The accelerated loss has made mountain glaciers one of the largest contributors to sea level rise, putting millions at risk of devastating floods and damaging water routes that billions of people depend on for hydroelectric energy and agriculture.

Stefan Uhlenbrook, the director of water and cryosphere at the World Meteorological Organization (WMO), said that about 275,000 glaciers remain globally which, along with the Antarctic and Greenland ice sheets, comprise about 70% of the world’s freshwater.

The United Nations World Water Development Report 2025, Mountains and glaciers: water towers:

As water towers, mountains play a vital role in freshwater storage and runoff generation. Shifts in the timing of seasonal snow-melt and from relatively reliable snow-melt freshets to more variable and less predictable rainfall-runoff regimes, coupled with losing the buffering capacity of glaciers, may decrease community resilience in times of stress (Somers et al., 2019; Carroll et al., 2024).

Downstream lowlands often contribute little to mountain-sourced river streamflow. Therefore, even communities residing thousands of kilometres away can depend on high mountains for their water resources (including groundwater) and derive important resilience benefits from the mountain cryosphere (Whitfield et al., 2020).

Awareness of, and preparedness for, declines in the ecosystem services that the cryosphere provides must be integrated into regional, national and global policymaking. Mitigation and adaptation efforts include: urban and agricultural water use with alternative storage systems to make up for lost cryosphere water storage; preserving timing of flows through surface and subsurface storage; improving irrigation technology and efficiency; and enhancing water-use efficiencies. However, while efficiency is important, strategies to reduce absolute water demand will be critical.