The Global Challenge of Melting Glaciers

In recent years, awareness of the world's rapidly melting glaciers has grown significantly. The primary focus tends to be on the colossal ice shelves of the polar regions, which is understandable due to their size and scenic allure. However, equally critical masses of ice in mountain ranges are also under threat, with implications that are just as concerning.

Mountain glaciers worldwide are retreating at alarming rates, often outpacing the melt of polar ice. These glaciers and snowpacks at high elevations are vital resources for over three billion people. Their cyclical melting and refreezing patterns once supported agriculture and industry by providing predictable weather and river flows. This predictability allowed societies to thrive and facilitated hydropower production, a cleaner alternative to fossil fuels. However, these patterns are now being disrupted, leading to potential calamity.

The consequences of these disruptions are dire and foreseeable. Every mountain range is experiencing rapid changes, and the rate of glacial melt is unprecedented when compared to the last millennium. Numerous smaller glacial areas are expected to vanish entirely in the coming decades.

Research from May 2024 indicates that the central range of Peru, near Lima, could lose 84 to 98% of its glaciers by 2050, with total disappearance anticipated by 2056. This alarming prediction comes as Peru has already lost over half of its tropical glaciers in the last 60 years, according to an October 2023 government report.

Alpine glaciers are experiencing similar declines. Previous studies using AI modeling and satellite data have shown a projected ice volume reduction of approximately 34%, with coverage area diminishing by around 32%. Projections suggest that alpine glaciers could lose more than 65% of their mass by 2050.

In Africa, the IPCC forecasts the complete loss of glaciers on the Rwenzori Mountains and Mount Kenya by 2030. Similar outcomes are anticipated for smaller glacial masses worldwide over the next fifty years, affecting regions including the European Alps, Pyrenees, Caucasus, North Asia, Scandinavia, tropical Andes, Mexico, eastern Africa, and Indonesia.

The Critical Impact of Himalayan Ice Loss

The melting of Himalayan glaciers poses a unique challenge due to the sheer number of people affected. The Himalayan mountains feed significant rivers globally, including the Indus, Ganges, and Brahmaputra, with two billion people relying on them for drinking water and agriculture. Many surrounding areas derive up to three-quarters of their irrigation from mountain runoff.

Rising temperatures have significantly altered weather patterns in the Himalayas, leading to reduced snowfall and snowpack depth. Snowpack is crucial as it provides insulation against warming by reflecting about 90% of incoming radiation back into the atmosphere. As snowpack diminishes, more glacial ice and rock surfaces become exposed, accelerating glacial melt.

A study of the South Col Glacier, the world's highest, revealed that decades of mass accumulation are now lost each year, with researchers noting that lower snowfall rates can increase glacial ablation by up to twenty times. Changes in wind patterns and atmospheric humidity further exacerbate this issue.

Researchers have reconstructed 4,798 glaciers across the Himalayas from the Little Ice Age to today, concluding that the observed ten-fold acceleration in ice loss far exceeds any centennial-scale rates recorded elsewhere.

The rapid melting of glaciers is the primary contributor to the formation of glacial lakes. As these lakes become more common, the risk of catastrophic GLOFs rises. Research by the International Centre for Integrated Mountain Development (ICIMOD) indicates that four GLOF events have occurred since 2003, causing significant damage and casualties. They estimate that 47 glacial lakes currently pose a substantial threat to communities downstream based on their size, location, and geological stability. The accelerating melt of glaciers will likely worsen this danger for affected populations in the coming years.

The Anatomy of Glacial Lakes

Glacial lakes emerge when glaciers retreat from their glacial till—the rocky debris produced by repeated glacial movements over thousands of years. Meltwater accumulates in low-lying areas between the till and the glacier's ice front or in geological depressions carved by glacial erosion.

Moraine-dammed glacial lakes are formed when water retention relies on natural earthen or stone barriers, while ice-dammed lakes depend on the glacier's ice front. Both types can become dangerous under certain conditions.

Moraine-dammed lakes can turn into GLOFs when water breaches these barriers, often due to sudden increases in lake volume caused by rockslides or calving from adjacent glaciers. Heavy rainfall or rapid snowmelt can also lead to excessive lake volume, as can seismic events that compromise the moraine structure.

Ice-dammed lakes may also experience GLOFs due to excessive volume, whether from sudden surges or gradual accumulation. As the water mass increases, it can lift the ice dam, allowing rapid water release beneath. Once a significant amount of water escapes, the remaining volume may no longer support the ice dam, resulting in a "resealing" effect that can lead to repeated flooding.

Both types of GLOFs can have severe downstream consequences, as an immense volume of water is suddenly introduced into narrow riverbeds, which are often bordered by steep terrain. The rushing water can carry debris, making the situation even more perilous.

GLOF Risks in the Himalayas

ICIMOD's GLOF dashboard tracks historical incidents, documenting 703 events that resulted in 7,008 fatalities over nearly two centuries. Notably, 23% of these involved the same lake body multiple times. Avalanches, rockfalls, and landslides accounted for 54% of incidents, while heavy rainfall was responsible for 18%. The Karakoram range is identified as the region with the highest GLOF risk.

The frequency of GLOF events has increased since 1980, particularly in Southeastern Tibet and along the China-Nepal border since 2010. One study estimates that approximately 6,353 square kilometers of land are currently at risk from GLOF events, affecting over 55,000 buildings, 105 hydropower projects, and thousands of kilometers of infrastructure.

A case study of the 2016 Bhote Koshi River GLOF in Nepal detailed the destruction of 20 concrete houses, a boarding school, and parts of a customs office. Extensive road damage occurred, including along a crucial highway to China, while a hydropower plant suffered significant impacts. Rapid evacuations helped prevent loss of life, but economic damages were estimated at around $70 million.

Between 1977 and 2020, Nepal experienced twenty-six GLOF events, nearly half of which originated outside its borders. This highlights the complexities of monitoring and managing these events, as glacial lakes can pose risks across multiple nations. One study indicated that one in six glacial lakes poses a danger to at least two countries, with expectations of a three-fold increase in risk over the next few decades. Currently, an estimated 15 million people live in areas at very high risk.

Mitigating GLOF Risks

Unfortunately, few effective solutions exist to mitigate the societal and economic impacts of GLOFs. Many high-risk areas lack the resources for large-scale interventions. However, community-based efforts are being implemented in various regions.

In Bhutan, initiatives aimed at educating communities about GLOFs and their potential triggers have gained traction. Similarly, my organization, the EALS Global Foundation, collaborates with Volunteer Corps Nepal (VCN) to inform villagers living along rivers susceptible to GLOFs.

Another strategy involves establishing early warning systems. In various regions of the Hindu Kush Himalaya, ICIMOD has initiated a community-based flood early warning system (CBFEW). This program trains volunteers to monitor flood risks and alert communities downstream when conditions become hazardous, allowing time for evacuations and the safeguarding of essential livestock and resources. EALS Global aims to enhance this system through advanced monitoring technologies.

While these measures are not foolproof, they represent steps toward reducing fatalities from GLOFs. However, until global action on climate change intensifies, the frequency of these events is likely to rise.

If you're interested in the experiences of the Sherpas, consider reading my related piece, "Chronicling the Lives of Sherpas."

Robert Vanwey is the co-director of the Dharma Farm School of Translation and Philosophy and serves as the executive director of the EALS Global Foundation.

For more insights from Rob, follow him on the Evidence Files Substack, where he explores technology, science, aviation, and the Himalayas, where he frequently resides.

The first video titled "Melting Glacial Lake in Nepal: A Threat to Communities" explores the dangers posed by the rapid melting of glacial lakes in Nepal, highlighting the risks to local communities and the urgent need for action.

The second video, "UN Chief Addresses Melting of Glaciers in the Mount Everest Region | United Nations," discusses the global implications of glacier melt, emphasizing the urgency of addressing climate change and its impact on vulnerable communities in the Himalayas.