Chinese Researchers Warn of Climate Change Link to Glacial Collapse and Rising Risks
Worth reading — 1 past UPSC question on this theme (Mains GS-1 2017).
2-minute summary
A study by Chinese researchers from the Institute of Mountain Hazards and Environment (Chinese Academy of Sciences) highlights a direct link between rising global temperatures and the glacial collapse on the Nepal-China border. Over the past six decades, the Tibetan Plateau's glacier area has shrunk by 24% overall—dropping from 51,000 to 39,000 square kilometers. This retreat is highly pronounced in the southern regions (including the Gangdise, Nyenchen Tanglha, and Himalayan ranges), where glaciers have shrunk by nearly 40%. Consequently, more than 14,000 glacial lakes have formed, covering over 1,100 square kilometers and expanding at an average rate of 1% annually near China's southern borders. This rapid expansion significantly escalates the risk of Glacial Lake Outburst Floods (GLOFs) and landslides, threatening downstream countries like India and Nepal. Experts emphasize the urgent need for transboundary mapping, real-time monitoring, and proactive hydrological data-sharing to mitigate downstream disasters.
Why it's in the news
Chinese scientists have linked rising global temperatures to a deadly glacial collapse on the Nepal-China border, warning of escalating Glacial Lake Outburst Flood (GLOF) risks across the Tibetan Plateau due to the rapid expansion of over 14,000 glacial lakes.
Facts to remember
- A study by Chinese researchers highlights a direct link between rising global temperatures and glacial collapse on the Nepal-China border.
- Glacier retreat in southern regions including the Gangdise, Nyenchen Tanglha, and Himalayan ranges has seen glaciers shrink by nearly 40%.
- More than 14,000 glacial lakes have formed, covering over 1,100 square kilometers and expanding at an average rate of 1% annually near China's southern borders.
Background and context
The Hindu Kush-Himalayan (HKH) region and the Tibetan Plateau, often referred to as the 'Third Pole', hold the largest reserve of freshwater ice outside the polar regions. Due to global warming, this region is heating up at nearly double the global average rate, leading to rapid cryospheric melt. When glaciers retreat, they leave behind loose debris and ice that block meltwater, forming moraine-dammed glacial lakes. These natural dams are structurally unstable. Sudden triggers—such as ice avalanches, earthquakes, or heavy rainfall—can cause these dams to breach, resulting in catastrophic Glacial Lake Outburst Floods (GLOFs). Past disasters, such as the 2013 Kedarnath tragedy and the 2023 South Lhonak Lake outburst in Sikkim, underscore the vulnerability of downstream Indian states. Because major river systems like the Indus, Ganga, and Brahmaputra originate in this region, cryospheric changes on the Tibetan Plateau have profound geopolitical, ecological, and socio-economic implications for South Asia.
Constitutional provisions
- Article 48A — Directive Principles of State Policy directing the State to protect and improve the environment and safeguard forests and wildlife.
- Article 51A(g) — Fundamental Duty of every citizen to protect and improve the natural environment, including forests, lakes, rivers, and wildlife.
Committees and reports
- IPCC Special Report on the Ocean and Cryosphere in a Changing Climate (SROCC) — Highlighted the accelerating retreat of glaciers and the projected increase in GLOF hazards across high-mountain Asia.
- NDMA Guidelines on Management of Glacial Lake Outburst Floods (GLOFs) — Provides a specialized framework for risk mapping, monitoring, structural mitigation, and community-based early warning systems in India.
Government schemes
- National Mission for Sustaining the Himalayan Ecosystem (NMSHE) — One of the eight missions under the National Action Plan on Climate Change (NAPCC), aimed at monitoring the health of Himalayan glaciers and protecting the mountain ecology.
- National GLOF Risk Mitigation Project — Focused on structural and non-structural measures, including lake lowering and early warning systems, in high-risk states like Sikkim and Himachal Pradesh.
International organisations
- International Centre for Integrated Mountain Development (ICIMOD) — An intergovernmental regional organization that facilitates regional cooperation, research, and data-sharing on cryosphere monitoring and disaster risk reduction across the Hindu Kush Himalayas.
Previous UPSC questions on this theme
- Mains GS-1 2017 — How does the cryosphere affect global climate?
Mains practice: The rapid melting of glaciers on the Tibetan Plateau poses a severe threat of Glacial Lake Outburst Floods (GLOFs) to downstream regions. Discuss the factors driving this hazard and suggest a comprehensive strategy for risk mitigation and transboundary cooperation.
The Tibetan Plateau, known as the 'Third Pole', is experiencing unprecedented cryospheric melt. Recent studies indicate that the plateau's glacial area has shrunk by 24% over sixty years, leading to the formation of over 14,000 glacial lakes. This rapid retreat significantly escalates the risk of Glacial Lake Outburst Floods (GLOFs) downstream.
**Factors Driving the GLOF Hazard:**
• **Accelerated Global Warming:** The high-altitude Himalayan region is warming at a rate much faster than the global average, causing rapid glacial retreat and thinning.
• **Unstable Moraine Dams:** As glaciers retreat, they leave behind loose rock and debris (moraines) that dam meltwater. These natural barriers are structurally weak and highly susceptible to breaching.
• **Triggering Events:** Sudden ice avalanches, rockfalls, or cloudbursts can displace water in glacial lakes, causing waves that overtop and breach the fragile moraine dams.
• **Glacial Collapses:** Structural instability within the glaciers themselves leads to sudden surges or collapses, as seen recently on the Nepal-China border.
**Comprehensive Strategy for Risk Mitigation:**
• **Early Warning Systems (EWS):** Deploying real-time sensor-based monitoring networks and satellite-based surveillance on high-hazard lakes (such as Sikkim's South Lhonak Lake) to provide advance warning to downstream communities.
• **Structural Engineering Interventions:** Implementing controlled draining of high-risk lakes through siphoning, tunneling, or constructing open channels to reduce water volume.
• **Land-Use Planning:** Demarcating hazard zones in downstream valleys to restrict critical infrastructure development (like hydropower plants and highways) in high-risk floodplains.
• **Transboundary Data Sharing:** Establishing institutional mechanisms with China and Nepal for real-time hydrological and meteorological data-sharing, as cryospheric hazards transcend political borders.
• **Strengthening Regional Frameworks:** Actively leveraging platforms like ICIMOD to foster joint scientific research, capacity building, and coordinated disaster response protocols.
**Conclusion:**
Addressing the threat of GLOFs requires moving beyond localized responses toward a integrated, science-led regional framework. Protecting the lives and infrastructure of millions in the Indus, Ganga, and Brahmaputra basins depends on proactive transboundary climate diplomacy and robust disaster-resilient planning.
Prelims practice questions
Q1. With reference to the 'Third Pole' of the Earth, consider the following statements: 1. It contains the largest reserve of freshwater ice outside the polar regions. 2. The Gangdise and Nyenchen Tanglha mountain ranges are located in this region. 3. Glacial retreat over the last six decades has been uniform across both the northern and southern slopes of the Tibetan Plateau. Which of the statements given above are correct?
- 1 and 2 only
- 2 and 3 only
- 1 and 3 only
- 1, 2 and 3
Answer: A. Statements 1 and 2 are correct. The Tibetan Plateau and the Hindu Kush Himalayas are referred to as the Third Pole due to their vast ice reserves. The Gangdise and Nyenchen Tanglha are key mountain ranges within this region. Statement 3 is incorrect because glacial retreat is not uniform; it is far more pronounced in the southern part of the plateau (shrinking by about 40% over 60 years) compared to the overall average of 24%.
Q2. The 'National Mission for Sustaining the Himalayan Ecosystem' (NMSHE) is coordinated by which of the following Union Ministries?
- Ministry of Earth Sciences
- Ministry of Environment, Forest and Climate Change
- Ministry of Jal Shakti
- Ministry of Science and Technology
Answer: D. NMSHE is one of the eight missions under the National Action Plan on Climate Change (NAPCC). Uniquely, it is coordinated and implemented by the Department of Science and Technology under the Ministry of Science and Technology.
Q3. Which of the following best describes the phenomenon of a Glacial Lake Outburst Flood (GLOF)?
- A flash flood caused exclusively by cloudbursts in non-glacial mountain valleys.
- The gradual rise of sea levels due to the melting of continental ice sheets.
- The seasonal flooding of rivers fed by glacial meltwater during peak summer months.
- The sudden release of water from a lake dammed by unstable glacial ice or moraine.
Answer: D. A GLOF is a disaster that occurs when a natural dam containing a glacial lake (often made of unstable moraine or ice) fails, leading to a sudden, catastrophic release of water downstream.
Revision flashcards
- What is the 'Third Pole' and why is it significant? It refers to the Tibetan Plateau and Hindu Kush-Himalayan region. It is significant because it contains the largest reserve of freshwater ice outside the polar regions and feeds major Asian river systems.
- What percentage of glacial area has shrunk on the Tibetan Plateau over the past 60 years? About 24% overall, with the southern ranges (Gangdise, Nyenchen Tanglha, and Himalayas) experiencing a much higher retreat of approximately 40%.
- How many glacial lakes have been mapped on the Qinghai-Tibet Plateau according to recent studies? Over 14,000 glacial lakes, covering a combined area of more than 1,100 square kilometers.
- What is a moraine-dammed lake? A lake formed when meltwater is trapped behind loose rock, soil, and debris (moraine) deposited by a retreating glacier. These dams are structurally weak and prone to sudden failure.
- Which Indian state experienced a catastrophic GLOF in October 2023 due to the breach of South Lhonak Lake? Sikkim. The outburst destroyed the Teesta-III dam and caused widespread damage downstream.