Author: Andrea Egan Karma Lodey Rapten Dario Vespertino

Achieving the impossible: Preventing glacial lake outburst floods in the Third Pole, a look at action in Bhutan, Nepal, and Pakistan

Source(s): United Nations Development Programme (UNDP)

During the heroic age of polar exploration at the end of the 19th century and the beginning of the 20th, both the North and South Poles were attained by expeditions mustering dozens of specialists, the latest technological advancements, and the support of nation-states and major corporations.

Achieving these feats required previously unimaginable levels of perseverance and cooperation.

Third Pole

The difficulty in accessing the region, the vast expanse of unforgivingly frigid mountainous terrain, and the area’s prominence in the popular imagination led to a new appellation for the mountain range: the Third Pole.

It took nearly a half-century for the next great inaccessible subject of expeditions – Mount Everest – to be summited.

An ice mass rivalling the North and South pole

There is a further meaning of the Third Pole terminology that persists long after Everest was first climbed.

This vast frozen terrain, harbours the largest ice mass outside the North and South Polar Regions – hence, another iteration of the Third Pole concept.

An outsized significance for the wider world

Containing Mount Everest and encompassing over 5 million square kilometres with an average altitude of over 4,000 metres above sea level, the stores of water on the Third Pole provide freshwater resources to more than two billion people, regulate the climate, protect biodiversity, and have profound socioeconomic importance.

The Third Pole describes the area of Asia that contains continuous ranges of high glaciated mountains. It is the 3rd largest storage of frozen water on Earth and contains every peak taller than 7,000 meters. The Third Pole’s cryosphere, or frozen water, is preserved in a variety of places, including snowfields, glaciers, permafrost, and seasonal ice on lakes and rivers.

In the Third Pole region, glaciers provide a key source of dry-season water across ten major river systems; diminution of this water source affects agriculture, drinking water, and hydroelectricity production.

Over 240 million people live in the Himalaya and surrounding mountain ranges; 1.7 billion live in the river basins downstream, and food grown in these river basins feeds 3 billion people globally.

This vital ecological buffer and biodiversity hotspot has outsized significance for the wider world.

As the ice melts, danger lurks

But as these enormous glaciers melt, danger lurks.

It’s a problem that requires the same amount of perseverance and cooperation that summitting the poles more than a century ago required – i.e. mustering dozens of specialists, the latest technological advancements, and regional cooperation that transcends borders.

A dire analysis

In 2019 the International Centre for Integrated Mountain Development (ICIMOD) published comprehensive analysis of how climate change will affect the glaciers of the Himalaya, Hindu Kush, Karakoram, and Pamir mountains, which together form an arc across Afghanistan, Pakistan, China, India, Nepal, Bhutan, and Myanmar.

The study warned that, depending on the rate of global warming, one-third to two-thirds of the region’s approximately 56,000 glaciers will disappear by 2100.

Flash floods threaten more people than thought

The melting rates in High Mountain Asia (a term used for the same region in the IPCC Special Report on the Ocean and Cryosphere in a Changing Climate) are higher than the global average, but the key difference from the North and South Poles and other mountainous regions is that the Third Pole contains a larger volume of frozen water.

Additionally, the changes here will be felt by a far larger number of people.

Tsunami from the sky

As these glaciers recede across the region, the number of glacial lakes has grown.

Glacial lakes can grow quickly, and are often only tenuously held in check by moraine dams, glacial ice or even just bedrock. When any part of these fragile buffers fail, usually via breaching, slope failure, overtopping or other failure mechanisms, the resulting deluge is a glacial lake outburst flood, or GLOF. 

Sometimes colloquially referred to as a ‘tsunami from the sky’, the GLOF drains the entire lake down neighbouring valleys and can threaten people’s lives, livelihoods and regional infrastructure.

At least 65 GLOFs have been recorded in the Himalaya since 1930. These GLOFs have destroyed roads, trails, houses, fields, hydropower plants and human lives, as happened during the Dig Tsho GLOF in Nepal in 1985. Newly formed glacial lakes in the region have continued to grow rapidly, causing alarm.

As we examine work supporting GLOF responses in Nepal, Bhutan and Pakistan, a number of dangerous lakes have been identified: 21 in Nepal, 17 in Bhutan, and 33 in Pakistan. Working to mitigate the risks is the focus of multiple projects facilitated by UNDP and member-state governments.


Nepal is home to 8 of the 10 highest mountain peaks in the world, including Mount Everest (8,848m), whose snowpack and glaciers maintain the perennial flow of major domestic rivers and the Ganges in India.

In 2016, in partnership with the Global Environment Facility and UNDP, the Government of Nepal successfully lowered water levels in the recently formed Imja Tsho glacial lake, and installed community-based early warning and response systems to mitigate climate risks.

These projects have the distinction of being among the world’s highest-altitude adaptation projects, working in terrain above 5,000m, and culminating in joint work between the Nepal Army, Government of Nepal, Global Environment Facility (GEF), and UNDP.

Building on this previous work, the Government of Nepal is now designing a new UNDP-supported, Green Climate Fund-financed project, Protecting livelihoods and assets at risk from climate change induced flooding in glacial river basins of Nepal, to take up the baton.

The project objective is to safeguard the lives and livelihoods of 327,500 people and their physical and economic assets from the climate-induced threat of GLOFs and related hazards.


In Bhutan, the spectre of GLOFs is a daily reminder of the personal consequences of climate change.

Residents in the country’s remote highland communities describe living in constant fear of GLOFs after a 1994 flood washed out sections of the country’s Lunana region in the Gasa district, and wreaked havoc on lives, livelihoods and properties further downstream in Punakha and Wangdue districts.

Lunana region has the distinction of being one of the highest human settlements on earth, and harbours four glacial lakes, three of which are among the country’s 17 potentially dangerous glacial lakes.

Because GLOFs hit so suddenly, with <20 minutes to evacuate or move to higher ground, fears of floods keep residents up at night, worrying that every distant icefall or avalanche they hear is an incipient flood.

In response, and in collaboration with the Government, UNDP supported efforts to establish early warning systems, improve community disaster preparedness and response capacity, and lower lake levels.

Though these initiatives improve conditions, steadily-melting glaciers necessitate ongoing work.


In Pakistan, though the dramatic July 2022 lowland flooding might have captured the greatest amount of international attention, it was in fact preceded by a heatwave-triggered GLOF earlier in the year.

In May, the city of Nawabshah suffered through temperatures of 49.5° C, the hottest temperature recorded on earth up to that point in 2022.

These extremes of heat take on special urgency in the mountains, where spiking temperatures can rapidly undermine glacial ice and moraine complexes.

In the Hunza region, the lake next to Shisper Glacier burst following the heatwave, destroying agricultural land, infrastructure, and homes. Both permutations of floods serve as painful reminders of the need for reducing risk and building climate resilience throughout the country.

In the mountains of Gilgit-Baltistan and Khyber Pakhtunkhwa - with the assistance of the Green Climate Fund, UNDP and the Pakistan government – partners are implementing a multi-year GLOF-II project.

The project is working to scale up early warning systems, install protective infrastructure, repair and rehabilitate irrigation channels, and stabilize slopes using bio-engineering techniques. In addition to bolstering institutional support, the project is establishing Community Based Disaster Risk Management Committees, and centers may be added along with safe havens and safe access routes.

This work will benefit almost 700,000 people directly, and ≈29 million people indirectly.

Building on previous work, like the Reducing Risks and Vulnerabilities from Glacier Lake Outburst Floods in Northern Pakistan project, the current initiative builds upon the experiences, data, and information and coordination networks that were established.

The previous GLOF project, started in 2011 and financed by the Adaptation Fund, established a set of is proven interventions.

Expanding on this, and drawing from the institutional and management frameworks established, the current project is more cost-effective than the implementation of a separate new initiative and builds upon strengthened local capacities and previous experiences.

An exciting partnership to enhance large-scale coordination

Improving resilience to the GLOF threat requires data and information, capacity-building and early warning systems, as well as better designed infrastructure. This calls for sufficient funding, – coming from both public as well as private sources and innovative finance, large-scale and regional coordination, and governments’ ownership.

Responding to the need for large-scale and regional coordination, in September 2022, UNDP and ICIMOD have signed a Memorandum of Understanding (MoU) and have agreed to collaborate to establish a joint framework for regional cooperation to develop and share knowledge, promote capacity development, develop policies and practices, and enhance collaboration in the Hindu Kush Himalayan countries.

With four decades of experience and relationships in the region, ICIMOD is supporting a greener, more inclusive, and climate resilient Third Pole.

This recent commitment to an expanded partnership demonstrates how ICIMOD and UNDP can work together to promote regional cooperation, and accelerate transboundary climate risk reduction and adaptation to climate change through data sharing and a joint strategy to enhance resilience, socio-economic security and food security.

Speaking after the signing of the UNDP-ICIMOD MoU:

“I am pleased to sign this agreement to deepen our long-standing partnership to build resilience in the Hindu Kush Himalayan countries,” said Ms. Wignaraja. “Addressing complex challenges facing the region requires transboundary cooperation among the countries sharing the same river basins. In the case of the Himalayas, this would need to cover the entire Ganges River basin, involving China, Nepal, Bangladesh, and India. We would encourage the sharing of climate data and technology; climate security and risk sensitivity planning; and cross border financing and insurance for flood resistant infrastructure and coverage of loss and damage.”

An emblematic call for action

Globally, the loss of snow and ice from the Third Pole peaks needs to be seen not as a distant problem, but as a symbol and a symptom of a wider imbalance that calls for urgent action.

UNDP, together with the governments of the affected countries, is committed to achieving effective and lasting actions that limit the damage caused by climate change in High Mountain Asia.

The region is one of the most complex in the world along multiple axes, and only detailed environmental monitoring and research will detect vulnerabilities and future challenges. UNDP is committed to mobilizing resources and action, as evidenced by a strong history of GLOF projects in the region and a unique ability to bring together a variety of sectors and actors. In a region where transboundary cooperation can be limited, governments will need to strengthen cross-sectoral institutions that can reach across typically siloed ministry structures.

The issues and problems that GLOFs present, cross multiple borders - both between subnational jurisdictions and between countries. This calls for developing effective communication platforms to ensure cross-border sharing of data, information, knowledge and experiences.

As parties gather for the UN Framework Convention on Climate Change – 27th Conference of the Parties (COP27) at Sharm El-Sheik, Egypt (6 – 18 Nov 2022), urgent action to curb emissions is needed to secure water supplies, protect livelihoods and prevent disasters across the region.

Limiting global warming is a matter of life and death for communities struggling to cope with weather extremes, and who lack the economic resources to adapt. Like most of the developing world, South Asian nations are pursuing mitigation targets with their own efforts, but they also rely on financial support from their more developed counterparts to enhance mitigation and adaptation, and meet their pledges under the Paris Agreement.

It is hoped that COP27 will recognize the diverse needs of mountain communities and come forward with much-needed support to improve the resilience of communities in the region.

COP27 is a make-or-break moment for global action on climate change.

The world is not on track to keep warming within 1.5°C, and events of the past year have made the path to success even more difficult.

A successful COP27 – which will include delivering on support for developing countries to deal with loss and damage caused by climate change – is essential to enhance international cooperation on climate action.

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Hazards Flood
Country and region Bhutan Nepal Pakistan
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