On 11 December, the world marks International Mountain Day, a global observance designed to highlight the importance of mountain ecosystems and the urgent challenges they face. The 2025 theme focuses on the role of glaciers in ensuring water security, food systems and livelihoods both within mountain regions and far beyond them.
Glaciers — Essential Engines of Life
Glaciers store nearly 70% of the world's freshwater, feeding rivers and lakes that sustain agriculture, hydropower and the daily lives of billions of people. Yet their accelerated melting is transforming into a global humanitarian and environmental crisis.
Glacier loss leads to: – reduced water availability and disruption of hydrological systems; – threats to agriculture and clean energy production; – increased risk of glacial lake outburst floods; – landslides, erosion and intensified sediment flows.
These impacts threaten lives and critical infrastructure downstream.
Why We Celebrate International Mountain Day
Mountains are invaluable natural systems that support the planet’s environmental and economic stability.
Key facts about mountain regions: – 15% of the world’s population lives in mountainous areas; – half of the world’s biodiversity hotspots are located in mountains; – around half of the global population depends on mountain-sourced water, food and energy.
Despite their importance, mountain regions face severe pressures. Climate change, land degradation, overexploitation and natural disasters undermine the resilience of communities — many of which are among the world’s poorest.
Glaciers are melting at unprecedented rates, altering water cycles and reducing freshwater reserves for millions. More than 311 million people in mountain areas of developing countries are affected by land degradation, including 178 million vulnerable to food insecurity.
This crisis affects everyone. Protecting glaciers and mountain ecosystems requires reducing carbon emissions, safeguarding natural resources and strengthening coordinated international action.
Background
International Mountain Day was established in 1992 through Agenda 21, Chapter 13 (“Managing Fragile Ecosystems: Sustainable Mountain Development”).
In 2002, the UN declared the International Year of Mountains, and the Day has been officially celebrated every year since 2003.
FAO serves as the lead UN agency coordinating the global observance.
