UPSC Mains 2023 GS3 Q18: model answer

The IPCC's Sixth Assessment Report projects global sea level could rise by about a metre by 2100 under high-emission scenarios, due to thermal expansion of warming seas and melting ice. The Indian Ocean is warming faster than average.

Impact on India

• Coastal cities: Mumbai, Kolkata, Chennai, Kochi and Surat face frequent flooding and storm surges.
• Deltas: the Sundarbans, Ganga-Brahmaputra, Mahanadi and Godavari deltas would lose land; islands like Ghoramara are already shrinking.
• Salinity: seawater intrusion into groundwater and farmland harms crops and drinking water.
• Livelihoods: fishers and coastal farmers displaced; climate migration to cities.
• Infrastructure: ports, refineries, power plants and naval bases at risk.
• Islands: Lakshadweep and parts of Andaman and Nicobar face erosion.
• Ecosystems: mangroves, coral reefs and turtle nesting beaches lost.

Impact on other Indian Ocean countries

• Maldives: most islands are about a metre above sea level, so its very existence is at stake.
• Bangladesh: large parts of its low coast could flood, displacing millions.
• Sri Lanka, Myanmar and Thailand: coastal cities and the Irrawaddy delta.
• Indonesia: Jakarta is sinking; the capital is being moved to Nusantara.
• Small island states: Seychelles, Mauritius and Comoros.

Regional effects

• Cross-border climate migration and pressure on India's borders.
• Shrinking baselines raise questions over maritime zones.

Response

• Mangrove belts (MISHTI), coastal zone planning and resilient infrastructure.
• Climate finance and the loss and damage fund for vulnerable states.
• India's leadership through CDRI, IORA and support to island neighbours.

Sea-level rise is a shared Indian Ocean threat that needs shared adaptation.