Key Facts and Data Points

  • Location & Size: West Antarctica; ~120 km wide, covering ~1.9 lakh sq. km.
  • Sea‑Level Risk: Holds enough ice to raise global sea level by >0.5 m if it collapses completely.
  • Current Contribution: Accounts for ~4 % of annual global sea‑level rise.
  • Ice Discharge: Nearly doubled over the past three decades.
  • Collapse Timeline: Scientific assessments suggest a possible large‑scale collapse within 200–900 years.
  • Geographical Vulnerability: Bedrock slopes downward inland below sea level, allowing warm ocean water to melt the glacier from below.
  • Ice Shelf Role: Acts as a brace; thinning or fracturing accelerates glacier flow.

Background and Context

Thwaites Glacier is part of the West Antarctic Ice Sheet (WAIS). Its grounding line sits on a retrograde slope, making it highly susceptible to basal melting driven by intruding warm Circumpolar Deep Water. Recent satellite and airborne radar observations show accelerated thinning, grounding‑line retreat, and increased iceberg calving.

Significance for India / Governance / Policy

  • Coastal Vulnerability: A 0.5 m rise would exacerbate flooding, erosion, and storm surges along India's extensive coastline, affecting megacities like Mumbai, Chennai, and Kolkata.
  • Disaster Management: Highlights the need for robust Coastal Zone Management and National Disaster Management Plan updates.
  • Climate Commitments: Reinforces India's obligations under the Paris Agreement and the National Action Plan on Climate Change (NAPCC), especially the National Mission for Sustaining the Himalayan Ecosystem and National Mission for a Green India.
  • International Cooperation: Underlines the importance of scientific collaboration (e.g., IPCC, SCAR) and technology transfer for polar research.

Related Constitutional / Legal Provisions

  • Article 48A of the Constitution (Directive Principle) – protection and improvement of the environment.
  • Environment (Protection) Act, 1986 – empowers the government to regulate emissions and climate‑related impacts.
  • National Climate Change Action Plan (NCCAP) – integrates sea‑level rise projections into sectoral policies.

Implications for UPSC

  • Prelims: Factual data on glacier size, contribution to sea‑level rise, and timeline.
  • Mains: Analytical questions on policy response, coastal management, and international climate negotiations.

References