March 21 is declared as the World Day for Glaciers by the United Nations (UN). The UN in its resolution A/RES/77/158 declated the the World day for Glaciers along with the International Year of Glaciers 2025. It encourage us all to act to preserve the vital role of glaciers in sustaining life on Earth for generations to come. What are glaciers A glacier is a large accumulation of mainly ice and snow, that originates on land and flows slowly through the influence of its own weight. Glaciers are found on every continent. Key messages Glaciers are critical to life - There are more than 275 000 glaciers in the world, covering an area of around 700 000 km². Glaciers are considered as important water towers, storing about 170 000 km3 of ice, which amounts to approximately 70% of the global freshwater. Glaciers are a source of life, providing freshwater to people, animals and plants alike. Glaciers are sensitive indicators of climate change and are retreating globally due to rising temperatures. Melting snow and ice from mountains are critical for freshwater supply in many regions. More than 2 billion people - equivalent to more than the combined populations of China and the United States— depend on glacier and snowmelt as a crucial source of freshwater. Melting glaciers, thawing permafrost and other cryospheric changes create new hazards and exacerbate existing hazards, increasing the risk of disasters. The ongoing decline in glaciers contributes to global sea-level rise, with today’s sea level about 20 cm higher than in 1900. Immediate, ambitious action to reduce greenhouse gas concentrations is needed to stabilize the climate, to preserve glaciers, and secure a sustainable future for all. Glacier monitoring provides important data for climate adaptation and mitigation strategies, and it needs to be expanded. Glaciers support the livelihoods and economies of billions around the world. Climate change involving deglaciation is severely impacting polar regions and global oceans. Youth inclusion can drive collective action and lead the way forward. Glaciers have cultural and spiritual significance. Glaciers are a crucial testimony of the Earth’s history. Glacier shrinkage unveils new post-glacial landscapes and ecosystems. Vanishing glaciers are impacting mountain tourism. Glaciers are projected to vanish in one-third of the current sites by 2050. Theme for 2026 - Glacier preservation World Day for Glaciers 2026 will mark the closing of the International Year of Glaciers’ Preservation (IYGP2025) co-led by UNESCO and WMO and the technical launch of the Decade of Action for Cryospheric Sciences (DACS 2025-2034), coordinated by UNESCO. The aim is to ensure that the momentum created during the International Year carries forward into a sustained global effort for the next decade. Glaciers are melting faster than ever. As the planet gets hotter, our frozen world is shrinking, making the water cycle more unpredictable. For billions of people, meltwater flows are changing, causing floods, droughts, landslides and sea level rise. Countless communities and ecosystems are at risk of devastation. As we work together to mitigate and adapt to climate change, glacier preservation is a top priority. We must reduce greenhouse gas emissions to slow down glacial retreat. And, we must manage meltwater more sustainably. Saving our glaciers is a survival strategy for people and the planet. About the Decade of Action for Cryospheric Sciences (2025-2034) The cryosphere, including glaciers, ice sheets, permafrost, sea ice and snow, stores around 70% of Earth’s freshwater, yet it is shrinking fast. Glaciers are losing mass every year; Arctic sea ice has declined by about 40% since 1979; and the Greenland and Antarctic ice sheets are melting at accelerating rates, with long-term implications for sea level rise. Cryosphere loss already affects water security, ecosystems, infrastructure and disaster risk worldwide. Our cryosphere - glaciers, ice caps, snow and permafrost - is melting at an unprecedented pace. Urgent action is needed to safeguard these vital frozen areas on which billions rely for freshwater and climate stability. Endorsed by the UN, the Decade of Action for Cryospheric Sciences (2025–2034) is a global effort to boost research and drive urgent action to protect Earth’s frozen areas. UNESCO has been mandated to lead this Decade and calls on scientists, governments, and communities worldwide to unite and protect the cryosphere and safeguard the billions of people who depend on them for their survival. Source : UN Related resources 2025 International Year of Glaciers’ Preservation