In News:

On World Day for Glaciers (March 21, 2025), the United Nations World Water Development Report 2025 revealed that glaciers globally are retreating at an alarming rate, with the Hindu Kush Himalaya (HKH) region witnessing the most severe impact — glacier loss accelerated by 65% between 2011–2020 compared to the previous decade.

Key Facts about Hindu Kush Himalaya (HKH) Region

• Geographical Spread: Extends over 3,500 km across 8 countries — Afghanistan, Bangladesh, Bhutan, China, India, Myanmar, Nepal, and Pakistan.
• Population Impact:
  • 240 million people live in the HKH region.
  • An additional 1.65 billion people downstream depend on its waters for drinking, agriculture, hydropower, and sanitation.
• Glacial Reservoir: Known as the “Third Pole” or “Water Tower of Asia”, the HKH stores more ice than anywhere outside the Arctic and Antarctic.
• River Systems: Source of 10 major river basins, including the Ganges, Indus, Brahmaputra, and Mekong.

Projected Glacier Loss (HKH and Global)

Temperature Rise (°C)                    HKH Glacier Volume Loss by 2100

1.5°C to 2°C                                      30%–50%

Above 2°C                                      ~45% (from 2020 baseline)

• Global Glacier Loss: Mountain glaciers may lose 26%–41% of total mass globally by 2100, affecting 1.1 billion people in mountain regions.

Disaster Risks from Glacier Melt

• Glacial Lake Outburst Floods (GLOFs):
  • Trigger flash floods and landslides.
  • Have caused over 12,000 deaths globally in the past 200 years.
  • In the HKH region alone, GLOFs are linked to over 7,000 deaths in the last 190 years.
  • Risk of GLOFs may triple by 2100.
• Glacial Lakes: Rapid warming is expanding the number and area of glacier-fed lakes, increasing hazard potential.

Cryosphere and Climate Change

• Hydrological Changes: Melting glaciers alter water runoff patterns, with varied impacts across river basins — increasing monsoon runoff in some while reducing dry-season flows in others.
• Hydropower Challenges:
  • Glacial melt initially boosts hydropower potential but may be offset by increased evaporation and reduced glacier mass over time.
  • Many hydropower and cryptocurrency mining projects are unregulated and stress fragile mountain ecosystems.
• Mountain-Based Industries: Lithium mining in the Andes, for instance, uses up to 2,000 m³ of water per tonne, intensifying water stress.

Governance and Cooperation Gaps

• Weak Water Governance: Mountain regions, including the HKH, lack effective transboundary cooperation due to mutual distrust and poor data sharing.
• Transboundary Action Plan (HKH):
  1. Enhance cooperation at all levels.
  2. Prioritize rights and knowledge of mountain people.
  3. Limit global warming to 1.5°C.
  4. Fast-track SDG implementation in mountain areas.
  5. Strengthen ecosystem resilience and biodiversity.
  6. Promote regional data sharing and scientific collaboration.

UN Actions and Global Recognition

• International Year of Glacier Preservation (IYGP): 2025
• Decade of Action on Cryospheric Science: 2025–2034 — to advance global efforts in glacier conservation, data collection, and sustainable development in cryosphere-dependent regions.