An old man stands by the river, staring at the water that has nurtured his village for generations. He remembers when the stream was full, a roaring silver ribbon cutting through the valley. It was more than water; it was life, sustaining his ancestors, their crops, their livestock. But now, the river is thinner, quieter — almost as if it, too, knows that time is running out. This is not just his story. It is the story of millions, from the Himalayas to the Andes, the Alps to the Rockies. It is the story of our world’s glaciers, melting faster than ever, sending a warning we can no longer ignore.
In 2023, glaciers experienced their greatest water loss in over 50 years, marking the second consecutive year in which all glaciated regions worldwide reported ice loss. Switzerland, for instance, lost 10% of its total glacier mass between 2022 and 2023, according to the World Meteorological Organization (WMO). The Intergovernmental Panel on Climate Change (IPCC) reports that glaciers have been losing approximately 273 billion tonnes of ice annually since 2000. Their disappearance is accelerating sea-level rise, disrupting weather patterns, and threatening water supplies for over two billion people.
2025 as international year
Recognising the urgency of this crisis, the United Nations General Assembly declared 2025 as the International Year of Glaciers’ Preservation and proclaimed March 21 of each year as the World Day for Glaciers, starting in 2025. During the year, global action will be mobilised through high-level political engagement, international scientific collaboration, and education campaigns. UNESCO will play a key role in this effort, contributing both through scientific research and advocacy.
During the launch event in Geneva, Dr. Lidia Brito, UNESCO’s Assistant Director-General for Natural Sciences, explained that the “50 UNESCO heritage sites with glaciers represent almost 10 percent of Earth’s glacier area”. However, a UNESCO study in 2022, ‘World Heritage Glaciers: Sentinels of Climate Change’, warns that glaciers in one-third of these sites could disappear by 2050, underscoring the need for urgent global action.
For centuries, glaciers have acted as natural reservoirs, storing freshwater and gradually releasing it to sustain rivers that quench thirst, irrigate fields, and power hydroelectric plants. In regions such as the Himalayas, the Andes, and the Alps, glacier-fed rivers such as the Ganges, the Yangtze, and the Amazon form the backbone of economies and ecosystems. However, rising temperatures are disrupting this balance. Water flows from mountains are becoming erratic.
More water is actually an illusion
Initially, increased glacial melt may seem beneficial — more water in rivers, more supply for cities and farms. But this is a dangerous illusion. Once glaciers reach a tipping point, they can no longer replenish themselves, leading to severe water shortages. UNESCO’s World Water Development Report 2025 highlights that 25 countries, home to a quarter of the world’s population, already face extremely high-water stress annually, a number set to rise as glaciers disappear. Cities such as Lima, La Paz, and Kathmandu, which depend on glacier-fed sources, are already experiencing worsening droughts and declining hydropower generation.
Beyond water shortages, glacier melt is triggering another disaster — Glacial Lake Outburst Floods (GLOFs). As glaciers retreat, they leave behind massive lakes, precariously held back by loose, unstable rocks. These natural barriers are fragile, and when they collapse, they unleash sudden, devastating floods. In October 2023, a GLOF from the South Lhonak Lake in Sikkim sent torrents of water crashing into the Teesta river, destroying infrastructure and killing dozens. A 2016 glacial lake burst in Tibet caused widespread damage in Nepal’s Bhotekoshi River basin. Countries such as Nepal, Bhutan and Peru are on the frontlines of this growing threat.
Glaciers are more than just frozen water — they are also essential to biodiversity. Many UNESCO-designated biosphere reserves depend on glacial meltwater to sustain fragile ecosystems. In the Hindu Kush Himalayas, glacial retreat threatens unique plant and animal species, disrupts river flows, and puts immense pressure on mountain biodiversity, destabilising ecological balance. As glaciers retreat, the need to integrate local knowledge with scientific approaches becomes even more urgent.
On climate literacy
Climate change is a pressing topic of discussion across all quarters — at policy tables, in classrooms, and in everyday conversations —as awareness continues to grow. But understanding the science behind it remains crucial. A 2021 UNESCO study, ‘Youth Demands for Quality Climate Change Education’, revealed a significant gap in young people’s understanding, with 70% of youth worldwide unable to explain climate change in detail. To address this, UNESCO, in partnership with other UN agencies, launched the Climate Science Literacy exhibition in 2022, designed to advance climate literacy by presenting complex issues in an engaging and accessible way.
The declaration of the World Day for Glaciers is a global call to action. Glaciers are not distant, frozen relics. They are the pulse of our planet’s water system. Protecting them is protecting our future. Governments must strengthen policies to curb emissions, invest in climate adaptation and implement strategic initiatives for glacier protection and sustainable water management. Individuals, too, play a role — by reducing carbon footprints, advocating for climate action and supporting sustainable water management practices.
As the United Nations Secretary-General, António Guterres, has emphasised, ongoing crises threaten the well-being of millions of people. To counter these threats, we must embrace a new paradigm of environmental stewardship, one that aligns with UNESCO’s vision to “reconcile with nature”.
On this World Day for Glaciers, let us listen to what glaciers are telling us. Their fate — and ours — is inextricably linked. Water is life, and glaciers are its reservoirs. Their protection is our shared responsibility.
Tim Curtis is Director, UNESCO, Regional Office for South Asia, and is a part of Team UN in India
Published – March 21, 2025 04:00 am IST
