Himalayan Glaciers Face Rapid Ice Loss, Threatening Regional Water Security
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Himalayan glaciers have lost ice equivalent to 24 meters of water depth between 1973 and 2023.
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Analysis by ICIMOD highlights sustained glacier shrinkage, with eastern Himalayas showing higher rates of loss.
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The Hindu Kush Himalayan (HKH) region, or 'Third Pole', is crucial for major river basins but faces Glacial Lake Outburst Flood (GLOF) risks and long-term water supply instability.
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Observation gaps exist, with only 38 out of over 60,000 glaciers having long-term data, prompting the use of 'benchmark glacier' concept by WGMS.
- ●Himalayan glaciers lost 24 meters of water depth equivalent ice mass from 1973-2023.
- ●The International Centre for Integrated Mountain Development (ICIMOD) conducted the analysis.
- ●The Hindu Kush Himalayan (HKH) region is home to over 60,000 glaciers, but only 38 have long-term observation.
- ●Glacier melt increases risks of Glacial Lake Outburst Floods (GLOFs) and impacts water supply.
Glacial Lake Outburst Flood (GLOF)
A GLOF is a sudden release of a significant volume of water from a glacial lake. These lakes form as glaciers melt, and they are often dammed by unstable moraine (debris left by glaciers). If the moraine dam fails due to factors like excessive meltwater, landslides, or seismic activity, it can lead to a catastrophic flood downstream.
Simple Analogy: Imagine a bathtub filled with water, where the drain is blocked by a pile of loose sand. If the sand suddenly gives way, all the water rushes out at once, causing a flood.
Glacier Mass Balance
Glacier mass balance refers to the net gain or loss of ice over a glacier's surface over a specific period, typically a year. It's determined by the accumulation of snow and ice (positive balance) versus the ablation (melting and sublimation, negative balance). A negative mass balance indicates the glacier is shrinking.
Simple Analogy: Like a bank account for a glacier. Deposits are snowfall, withdrawals are melting. If withdrawals exceed deposits, the balance goes down.
Reference and Benchmark Glaciers (WGMS)
The World Glacier Monitoring Service (WGMS) defines 'reference glaciers' as those with a minimum of 30 years of continuous mass-balance measurements, providing a reliable long-term record. 'Benchmark glaciers' are a newer category for glaciological programs that haven't reached the 30-year threshold but are in regions lacking reference glaciers, aiming to fill data gaps.
Simple Analogy: Reference glaciers are like long-term stock market indices, providing a complete historical view. Benchmark glaciers are newer, promising stocks that are being closely watched to build up their historical data.
International Centre for Integrated Mountain Development (ICIMOD)
An intergovernmental learning and knowledge sharing centre working on sustainable mountain development in the Hindu Kush Himalayan (HKH) region. It conducts research, promotes regional cooperation, and provides policy advice.
World Glacier Monitoring Service (WGMS)
Collects and publishes standardized data on glacier fluctuations from around the world. It is a service of the International Association of Cryospheric Sciences (IACS) and the World Data System (WDS).
Climate Change
Glacier melt is a direct indicator and consequence of global warming, driven by anthropogenic climate change.
Water Security
Himalayan glaciers are critical freshwater sources for major Asian rivers, impacting water availability for agriculture, drinking, and hydropower for billions.
Disaster Management
Increased glacier melt leads to the formation and expansion of glacial lakes, heightening the risk of Glacial Lake Outburst Floods (GLOFs), which require robust early warning systems and disaster preparedness.
Geopolitics
Shared water resources originating from the HKH region can become a point of cooperation or contention among riparian nations.
The Hindu Kush Himalayan (HKH) region spans across eight countries: Afghanistan, Bangladesh, Bhutan, China, India, Myanmar, Nepal, and Pakistan. It encompasses major mountain ranges including the Himalayas and Karakoram. Key river basins originating here include the Ganga, Brahmaputra, and Indus. Specific glaciers mentioned are Gara (Himachal Pradesh, India), Hamta (Western Himalaya), West Changri Nup (Central Himalaya), Gangju La and Thana (Eastern Himalaya). Regions like Sikkim, Zanskar, and Bhutanese Himalaya are noted for observation gaps.
Exam Relevance
GS Paper I (Geography - Physical Geography, Distribution of key natural resources), GS Paper III (Environment & Ecology - Climate Change, Disaster Management, Conservation). Questions can be conceptual, analytical, or map-based.
General Awareness (Geography, Environment, Current Affairs). Factual questions on organizations (ICIMOD, WGMS), locations, or key findings.
General Awareness (Current Affairs, Environmental Issues). Focus on key reports, organizations, and their implications.
General Awareness (Geography, Environment). Factual questions on mountain ranges, rivers, and environmental phenomena.
General Awareness (Geography, Environmental Security). Understanding of strategic geographical regions and their environmental challenges.
Previously Asked (PYQs)
Expected Questions
- ★UPSC may ask: 'Discuss the implications of rapid glacial melt in the Hindu Kush Himalayan region on India's water security and disaster management strategies.' or 'Analyze the challenges in monitoring Himalayan glaciers and the significance of 'benchmark glaciers'.'
- ★SSC may ask: 'Which organization recently reported significant ice loss in Himalayan glaciers?' or 'Which region is often referred to as the 'Third Pole'?'
Topic Frequency
High for UPSC (Environment, Geography), Medium for SSC/Railway (General Awareness).
Key Terms
A vast mountain system in Asia, often called the 'Third Pole', containing the largest ice mass outside the polar regions.
A sudden release of water from a glacial lake, often caused by the failure of a natural dam.
The net change in a glacier's mass over a period, indicating whether it is growing or shrinking.
International Centre for Integrated Mountain Development, an intergovernmental organization focused on sustainable development in the HKH region.
An international service that collects and disseminates standardized data on glacier fluctuations.
Must Remember
- •The HKH region is the 'Third Pole' and a critical water tower for Asia.
- •Significant ice loss has occurred in Himalayan glaciers over the past 50 years.
- •ICIMOD and WGMS are key organizations involved in glacier monitoring.
- •GLOFs are a major hazard associated with glacier melt.
Exam Tips
- •Focus on the geographical extent of the HKH region and the countries it covers.
- •Understand the environmental and socio-economic implications of glacier melt.
- •Memorize the roles and headquarters of key international organizations like ICIMOD and WGMS.
- •Be prepared for map-based questions related to mountain ranges and river basins.