Water towers in peril: Glaciers’ retreat threatens global freshwater security
- Pierre Lambert
- Jun 29
- 4 min read
The world’s mountain glaciers, often referred to as natural water towers, are melting at an alarming pace, jeopardising freshwater security, energy supply, food production, and cultural heritage for over 2 billion people. The 2025 United Nations World Water Development Report, Mountains and glaciers: Water towers, warns that these cryospheric systems contribute up to 60% of global annual freshwater flows, a foundational element for achieving SDG 6 (clean water and sanitation) and SDG 13 (climate action).
Since 1975, the world has lost an estimated 9,000 gigatonnes of glacier mass, equivalent to a 25-metre-thick ice block covering Germany. The past three years alone mark the most significant losses on record, driven by rising global temperatures and changing precipitation patterns. This results in a hydrological double jeopardy: a short-term surge in meltwater followed by long-term water scarcity, destabilising human systems, biodiversity, and food production worldwide.
Hydrological shock: Cascading risks
Glacial retreat magnifies the risk of glacial lake outburst floods (GLOFs), landslides, and seasonal droughts. Mountain regions such as the Rwenzori Mountains in East Africa may lose all glaciers by 2030, with devastating consequences for indigenous Bakonzo communities whose livelihoods and spiritual traditions are glacier-bound. Similarly, China has lost 26% of its glacier coverage since 1960, exposing the Tibetan Plateau, Asia’s “Third Pole”, to destabilised water flows.
Such risks extend well beyond highlands. Downstream cities and agriculture zones across South America, South Asia, and Europe depend heavily on glacier-fed river systems. Hydropower, supplying approximately 16% of global electricity, is particularly vulnerable to unpredictable seasonal flows.
Organising for resilience: Key global initiatives and organisations
To counter these accelerating threats, a global coalition of organisations is advancing glacier preservation and climate adaptation strategies through science, policy, and local engagement. These efforts are vital to realising the targets of the Sustainable Development Goals.
1. UNESCO and WMO – International Year of Glaciers’ Preservation (IYGP 2025)
The UN declared 2025 the International Year of Glaciers’ Preservation, co-led by UNESCO and the World Meteorological Organization (WMO). This initiative, endorsed by over 35 countries and 75 international organisations, promotes global cooperation through glacier monitoring, public awareness campaigns, and the establishment of 21 March as World Glaciers Day.The IYGP supports a new international framework for funding mountain adaptation, enshrined in the Dushanbe Glacier Declaration, adopted during the 2025 conference in Tajikistan.
2. World Glacier Monitoring Service (WGMS)
An essential scientific body based in Zurich, the WGMS operates under UNEP, UNESCO, and WMO. It collects long-term glaciological data, including mass balance, volume changes, and length variation, across over 30 countries. Its work underpins climate modelling and informs global water and disaster risk policy.
3. Ice Memory Foundation
A pioneering scientific initiative involving institutions from France, Italy, and Switzerland, Ice Memory collects and preserves ice cores from endangered glaciers in an Antarctic archive. These cores contain atmospheric and chemical data spanning thousands of years, an irreplaceable climate record for future generations and researchers.
4. Extreme Ice Survey (EIS)
Founded by photographer and scientist James Balog, EIS deploys time-lapse cameras at major glacier sites across Greenland, the Alps, Alaska, and the Himalayas. Its visual data is crucial in public advocacy and has featured in films and educational materials to foster climate awareness.
5. 25zero Project
Led by Australian explorer Tim Jarvis, 25zero tracks the retreat of equatorial glaciers on 25 peaks at 0° latitude. Combining mountaineering, storytelling, and data gathering, the initiative spotlights how climate change affects some of the world’s most remote ecosystems.
6. FAO’s Mountain Partnership
A UN alliance of 68 member governments, NGOs, and major groups, the Mountain Partnership promotes mountain-sensitive development, ecosystem services protection, and capacity building in mountain regions. It integrates glacier resilience into national SDG strategies, particularly in developing countries.
Local action and technological adaptation
Efforts are not confined to the international sphere. In the Swiss Alps, scientists are using reflective snow blankets and artificial snowmaking to slow glacial melt. In the Andes and Himalayas, local communities are setting up early warning systems and reinforcing glacial lakes to prevent GLOFs. Meanwhile, legal precedents are emerging, such as Peruvian farmers suing multinational corporations for contributions to glacier-linked flood threats, a sign of increasing climate accountability.
The retreat of the world’s glaciers symbolises a deeper crisis: the erosion of Earth’s hydrological stability. Their preservation is central not only to environmental sustainability but also to human security, energy resilience, and cultural survival. As the world mobilises under the banners of SDG 6 and SDG 13, protecting mountain freshwater systems must remain a top global priority.
The collective work of UNESCO, WMO, WGMS, Ice Memory, the Mountain Partnership, and others shows that solutions are within reach, but time is short. Future efforts must be bold, well-funded, and deeply cooperative.
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