First-ever UN Declaration on Sea Level Rise, and India’s Coastal Vulnerability

Syllabus: GS3/ Environment

Context

• The United Nations General Assembly adopted the first-ever UN Declaration on Sea Level Rise, which recognises rising sea levels as an existential threat.

Status of Global Sea-Level Rise

• Sea-level rise refers to an increase in the average height of the ocean surface relative to a reference point on land or the Earth’s geocentric reference system.
• Low-lying island nations are particularly vulnerable because much of their land lies only a few metres above sea level, exposing them to coastal erosion, flooding, saltwater intrusion and the loss of habitable land.
  • In 2015, the low-lying Republic of Kiribati said that climate change effects were threatening its existence as a nation. 
• Global mean sea level is rising at an accelerating rate. The WMO estimates that the rate increased from 2.1 mm per year during 1993–2002 to 4.7 mm per year during 2015–2024.

Leading Causes of Sea Level Rise

•  The global warming-driven melting of glaciers (accumulation of ice and snow that slowly flows over land) and ice sheets (glaciers which cover more than 50,000 square km of land).
• The thermal expansion of seawater, a process by which water expands as it warms up.
  •  With global temperatures rising, oceans are becoming warmer, and as a result, the volume of water is increasing as well. 
  • Thermal expansion of seawater is responsible for one-third to half of global sea level rise, according to the National Aeronautics and Space Administration (NASA).
• Fluctuations in land water storage: Global sea level is also affected by reservoir storage and groundwater removal.

Impacts 

• Rising sea levels. Waves and storm surges can reach further inland, accelerating the erosion of shorelines and damaging residences, roads, ports, and other infrastructure.
• Saltwater intrusion : The incursion of seawater into coastal aquifers and farmland, thus decreasing the supply of fresh water and perhaps affecting the agricultural output.
• Coastal ecosystems under jeopardy: Rising sea levels, warmer waters, and changing salinity are rapidly threatening reefs of coral, mangrove forests, tidal marshes and estuaries.
• Displacement and Migration: Groups may be compelled to migrate due to shortage of useable land creating concerns of livelihoods, land rights, citizenship and human rights.

Can a Country Retain Statehood Despite Losing Its Territory?

• Under the 1933 Montevideo Convention, a state is defined using four main criteria: a permanent population, a defined territory, a government, and the capacity to enter into relations with other states.
  • However, these criteria do not fully address the continuity of an existing state whose territory becomes uninhabitable or submerged due to sea-level rise.
• The International Law Commission (ILC), in its 2025 report, recognised the legal basis for preserving statehood, drawing on territorial integrity, self-determination, sovereign equality and legal stability. 
• The 2026 UN Declaration on Sea Level Rise affirms a presumption of continued statehood, indicating that the loss of territory due to sea-level rise does not automatically result in the loss of statehood.

Implications for India

• India welcomed the UN Declaration on Sea Level and supported stable marine zones and continuity of statehood, while maintaining the notion of Common but Differentiated Responsibilities and Respective Capabilities (CBDR-RC).
  • In the face of rising sea levels, fixing maritime boundaries preserves India’s territorial seas and those of fragile island states. 
  • It also strengthens India’s historic involvement with the Pacific island countries through the FIPIC (2014) and the Infrastructure for Resilient Island States (IRIS) program (2021).
• Large and Vulnerable Coastline: India has a coastline of approximately 11,098 km, along with numerous offshore islands.
  • Its coastal geography includes highly populated urban and industrial centres, deltas, estuaries, mangroves, beaches and low-lying islands.
• Importance of Island Territories: Lakshadweep in the Arabian Sea and the Andaman and Nicobar Islands in the Bay of Bengal extend India’s maritime presence and influence.
  • Stability of maritime boundaries therefore has implications for India’s EEZ, marine resources and strategic interests.
• Human Displacement: The Sundarbans illustrates the interaction between sea-level rise, coastal erosion, cyclones, salinity and human displacement.
  • Islands such as Ghoramara have experienced substantial land loss, while the disappearance of Lohachara demonstrates how erosion and inundation can permanently alter inhabited landscapes.

Policy Framework in India

• Coastal Regulation Zone Notification, 2019: It regulates development activities along India’s coastal stretches.
  • It seeks to balance coastal conservation, livelihood requirements and regulated development.
• Coastal states and Union Territories prepare Coastal Zone Management Plans (CZMPs) to regulate development according to coastal vulnerability and environmental conditions.
• The Survey of India has prepared a coastal hazard line incorporating factors such as shoreline changes and sea-level rise.
• International Engagement: India launched the Infrastructure for Resilient Island States (IRIS) initiative at COP26 in Glasgow in 2021. 
  • It seeks to support small island developing states in developing climate-resilient infrastructure.

Way Ahead

• Sea-level rise is no longer merely an environmental challenge; it is increasingly a question of human security, territorial integrity, international law and economic resilience.
• For India, the priority should be to translate this international commitment into risk-sensitive coastal planning, resilient infrastructure, ecosystem restoration, protection of vulnerable communities and a credible framework for climate-induced displacement.

Source: IE