Many glaciers will not survive 21st century, warns UN
KATHMANDU: On the first World Glaciers Day observed today (March 21, 2025), UN agencies in their reports warned that many glaciers will not survive the 21st century with five of the past six years recording the most rapid glacier retreat on record.
“An avalanche of cascading impacts on economies, ecosystems and communities, not just in mountain regions but at a global level” and of the extraordinary jeopardy changes in mountain glaciers and snow-pack pose to communities, ecosystems, and economies downstream.
The UN Water report, “Mountains and glaciers: water towers” issued to coincide with today’s first-ever UN World Glacier Day states, “The water resources we receive from mountains are literally melting away before our eyes” and confirms that the Third Pole, among Earth’s highest and most extensive glacier systems, are also among “the most vulnerable to ongoing changes” and are “disappearing at an alarming rate.”
While short-term impacts include floods, lake outbursts, and other hazards, in the long term, the study states, “reduced water flows and increased droughts are expected to jeopardize food, water, energy, and livelihood security in the HKH region as well as disrupt ecosystems and escalate risks of conflict and migration.”
ICIMOD, the leading intergovernmental knowledge and development centre for the Hindu Kush Himalaya, while commenting on the reports, said: “These reports serve as a wake-up call for anyone who thought they were immune to the catastrophic losses of snow and ice that global warming is unleashing on Earth’s mountains. As the studies state, with up to 60pc of the world’s freshwater originating in the mountains, ‘we are all ultimately downstream.’
“The studies rightly place mountain cryosphere at the very top of the climate science agenda. They confirm that mountain cryosphere is one of the most sensitive components of the Earth system to global climate change, but also that glaciers in the HKH region, which stores more ice and snow than any region outside the poles, are especially at risk due to their size, significance to massive population centres and crucial industrial activity, and the rate at which they are disappearing – far faster than global averages, said Pema Gyamtsho, ICIMOD Director General.
“In common with other mountain regions around the world, we are seeing a disaster already underway in our cryosphere, as global warming accelerates glacier melt, decreases snow cover, increases permafrost thaw, prompts more extreme rainfall events and natural hazards.
“What is unique about the HKH is that one in every two people in Asia today live in a river basin of one of the 10 transboundary rivers whose headwaters lie in these mountains. These include some of the most food insecure people on Earth. Hundreds of millions of these people, and the agriculture and energy systems on which they depend, are currently growing acclimatized to additional snow and ice-melt from global temperature rise, particularly during the hottest and driest parts of the year. These are resources that the science is certain we are set to lose as glaciers retreat more massively from 2050 on.
“This means that the safety of billions of people, including some of the most vulnerable people on Earth, rely on world leaders and businesses acting now to cut emissions to limit the worst impacts of temperature rise on our glaciers and snowpack.
“At ICIMOD, we will continue to advocate for those deep emissions reductions on the global stage. We will also seek to build adaptation capacity at the government and community level, to increase the flows of finance to our region so they are commensurate with risks, to press for a more holistic approach to management of water resources, underpinned by regional dialogue and transboundary collaboration.”
Approximately one-fourth of annual average runoff in the HKH’s major river basins comes from snow melt, with significantly higher contributions in the western region, reaching 77pc for Helmand, 74pc for Amu Darya, and 40pc for Indus. The depletion of snow cover is a growing threat to water availability in the region.
Sher Mohammad, ICIMOD Remote Sensing Specialist, states: “The river basins in the HKH region provide water for nearly two billion people worldwide for their food security. Lower snow accumulation poses a growing threat to water availability. The pattern of decreasing snow fall could be particularly alarming for mountain and downstream communities that are directly dependent on this snowmelt. This also means that relevant agencies need to come up with proper management plans to offset water stress.”
At 70pc of streamflow coming from glacier and snow-melt, the Indus is one of the HKH rivers that is most at risk from cryosphere changes. ICIMOD’s River Basins lead Faisal Mueen Qamer states: “The Indus is often referred to as the lifeline of Pakistan – its waters provide critical ecosystem services downstream for the country’s agricultural, energy and industrial sectors. Upstream changes in Pakistan’s 13,000 glaciers are already impacting people’s relationship with water use and management practices. These challenges are basin wide, which while could be addressed with better availability of data, also require greater climate diplomacy to build trust among key stakeholders.”