Why in News?
Sea-level rise (SLR) has transformed from a climate concern into a humanitarian, developmental, economic and geopolitical challenge, affecting coastal settlements, ecosystems, infrastructure and national sovereignty.
As per WMO, global mean sea-level rise accelerated from 2.1 mm/year (1993–2002) to 4.7 mm/year (2015-2024); 2024 recorded the highest annual rise in the satellite era.
According to UN, even under lower-emission pathways, sea levels will continue rising for centuries because of ocean warming and ice-sheet responses.
Example: Tuvalu, Kiribati and Maldives face simultaneous risks of inundation, erosion, freshwater stress and livelihood loss.
Statehood, Maritime Rights and Climate Justice
International-law dilemma: The Montevideo Convention, 1933 identifies permanent population, defined territory, government and capacity for international relations as traditional elements of statehood.
Continuity of statehood: The 2026 UN Declaration on Sea Level Rise supports a presumption that States retain their sovereignty and international legal personality despite climate-induced territorial loss.
Maritime stability: The declaration supports stability of established maritime zones under UNCLOS, protecting maritime entitlements despite physical coastline retreat.
- Example: For Pacific island States, stable maritime zones safeguard access to fisheries and other marine resources even if parts of their land become uninhabitable.
Climate justice: India's advocacy of Common but Differentiated Responsibilities and Respective Capabilities (CBDR-RC) emphasises greater responsibility and financial contribution from countries with higher historical emissions and greater capacity.
India’s Vulnerability and Strategic Stakes
India has approximately 11,098 km of coastline and 1,298 offshore islands and islets, making coastal resilience important for both development and maritime security.
Strategic significance: Lakshadweep and the Andaman & Nicobar Islands strengthen India's maritime presence across the Arabian Sea and Bay of Bengal; stable maritime zones therefore protect strategic and economic interests.
NCCR/MoES assessment: Around 33.6% of India's mainland coastline was eroding, 26.9% accreting and 39.5% stable during the assessed period.
- Example: The Sundarbans faces interacting risks from SLR, erosion, cyclones and land subsidence.
Ghoramara Island: Its area reportedly declined from approximately 7.2 sq km in 1972 to 3.6 sq km in 2022, demonstrating long-term land loss and displacement.
2025 peer-reviewed assessment: Nearly 45 million Indians could be at risk from SLR by 2050, indicating substantial potential exposure to displacement and livelihood disruption.
Infrastructure and Governance Challenges
Urban exposure: Mumbai, Kolkata, Chennai and Surat face risks to dense settlements, transport, drainage, ports, industries and other critical infrastructure.
Scientific evidence: A 2025 assessment reported observed SLR between 1987–2021 of approximately 4.44 cm in Mumbai, 2.73 cm in Haldia and 2.38 cm in Visakhapatnam.
CRZ challenge: The Coastal Regulation Zone (CRZ) Notification, 2019 primarily uses the High Tide Line as a regulatory reference, while future SLR and erosion require more dynamic planning.
Hazard-line approach: Survey of India hazard-line mapping incorporates coastal hazards and shoreline changes and can support more climate-resilient land-use planning.
Displacement gap: India lacks a comprehensive statutory framework specifically addressing gradual climate-induced displacement, including land rights, rehabilitation and livelihood restoration.
- Example: Relocated communities in the Sundarbans have faced challenges involving secure tenure and livelihood continuity.
Comparative example: Fiji’s Climate Change Act, 2021 provides a framework for planned climate-related relocation.
Way Forward
Dynamic coastal regulation: Integrate projected SLR, erosion rates and storm-surge risks into coastal setbacks and infrastructure design; progressively strengthen hazard-line-based planning.
Planned relocation: Enact a national framework ensuring land titles, housing, livelihood restoration, social protection and community participation.
Nature-based adaptation: Restore mangroves, wetlands, dunes and coral reefs alongside targeted coastal protection infrastructure.
Resilient infrastructure: Apply climate projections to ports, roads, railways, drainage, power systems and coastal urban planning.
Early warning and monitoring: Expand tide gauges, satellite observation, shoreline mapping and multi-hazard warning systems.
Finance: UNEP estimates developing countries' adaptation needs at over $310 billion annually by 2035, compared with about $26 billion in international public adaptation finance in 2023.
International cooperation: India should continue advocating CBDR-RC, adequate and predictable adaptation finance, technology transfer and stable maritime entitlements, while strengthening domestic coastal resilience.
