Melting Water Towers Will Aggravate Global Crises, Many Glaciers Will Not Survive This Century

Glaciers are melting at an unprecedented rate due to rising global temperatures triggered by human-induced climate change. If current trends continue, glaciers in many regions will not survive the 21st century, potentially jeopardizing the livelihoods of hundreds of millions of people living downstream, UN climate experts warned on the inaugural World Day for Glaciers, observed on March 21, 2025.

Accelerating glacier melt risks unleashing a cascade of impacts on economies, ecosystems, and communities—not just in mountain regions but globally. The first World Glaciers Day emphasized the need for immediate and coordinated international efforts. It coincides with World Water Day on March 22. The United Nations General Assembly proclaimed 2025 as the International Year of Glaciers’ Preservation and established 21 March as the annual World Day for Glaciers.

Alarming Glacier Loss

Five of the past six years have seen the most rapid glacier retreat on record. The period from 2022 to 2024 saw the largest three-year loss of glacier mass on record. In many regions, what was once called glaciers’ “eternal ice” will not survive the 21st century, according to reports from the World Meteorological Organization (WMO) and the World Glacier Monitoring Service (WGMS).

“WMO’s State of the Global Climate 2024 report confirmed that from 2022 to 2024, we saw the largest three-year loss of glaciers on record. Seven of the ten most negative mass balance years have occurred since 2016,” said WMO Secretary-General Celeste Saulo. “Preservation of glaciers is not just an environmental, economic, and societal necessity. It’s a matter of survival,” she said.

The World Glacier Monitoring Service estimates that glaciers (separate from the continental ice sheets in Greenland and Antarctica) have lost more than 9,000 billion tons since records began in 1975. “This is equivalent to a massive ice block the size of Germany with a thickness of 25 meters,” says Prof. Dr. Michael Zemp, Director of the WGMS.

The 2024 hydrological year marked the third consecutive year in which all 19 glacier regions experienced a net mass loss, totaling 450 billion tons—the fourth most negative year on record. While the mass loss was relatively moderate in regions like the Canadian Arctic or the Greenland periphery, the glaciers in Scandinavia, Svalbard, and North Asia experienced their largest annual mass loss on record.

Threat to Global Water Security

The United Nations World Water Development Report 2025 highlights the devastating consequences of glacial retreats on freshwater resources. Mountains supply up to 60% of the world’s annual freshwater flows, with more than two billion people relying directly on glacial meltwater. However, rapid glacier depletion threatens these vital resources.

From 2000 to 2023, the global glacier mass loss totals 6,542 billion tons – or 273 billion tons of ice lost per year, according to the study. This amounts to what the entire global population currently consumes in 30 years.

In High Mountain Asia, home to the world’s third-largest ice reserve after Antarctica and Greenland, glaciers shrank by 5% to 21% from 2000 to 2023 due to climate change. The Hindu Kush Himalayas, containing nearly 100,000 glaciers, feed ten of Asia’s largest rivers, including the Indus, Brahmaputra, and Ganges, which sustain nearly a quarter of the world’s population. Seasonal glacial melt provides enough water to meet the annual municipal and industrial needs of countries like Pakistan, Afghanistan, and India.

Rising Sea Levels and Flood Risks

The latest data indicates that 25% to 30% of sea level rise comes from glacier melt. Melting snowcaps are causing sea levels to rise by approximately one millimetre every year, a seemingly small figure that translates to the displacement of 200,000 to 300,000 people annually.

The retreat of glaciers also intensifies the risks of natural disasters such as glacial lake outburst floods (GLOFs), which can be devastating. India is particularly vulnerable, with over three million people at risk of such floods. The Kedarnath disaster in 2013 and the 2023 Sikkim flood—caused by the rapid melting of the South Lhonak Glacier—underscore the growing threats posed by glacial retreat.

According to projections, extreme rainfall and glacier melt could increase the peak flow of a 50-year return flood by 51% in the Upper Indus Basin, 80% in the Upper Brahmaputra Basin, and 108% in the Upper Ganges Basin by 2100 under high-emission scenarios.

Economic and Energy Implications

Glacial retreat poses severe risks to energy production, particularly hydropower. In India, 52% of hydroelectric power is generated from Himalayan rivers, making the country highly vulnerable to changes in water availability. A decline in glacier-fed river flows after mid-century will significantly impact agriculture, drinking water supplies, and overall economic stability.

WMO Secretary-General Celeste Saulo emphasized that glacier preservation is not just an environmental or economic issue but a matter of survival. “The loss of glaciers is an irreversible tipping point. We must act now to cut emissions and implement sustainable water management strategies,” she urged.

Glacier of the Year 2025

On the first World Day for Glaciers, South Cascade Glacier was selected as Glacier of the Year 2025. Located in the Cascade Range of Washington, United States, the South Cascade Glacier has been continuously monitored since 1952, providing one of the longest uninterrupted records of glaciological mass balance in the Western Hemisphere.