UNGA Declaration on Sea-Level Rise: Global Risks, Adaptation and Coastal Resilience

Subject: GS 03: Environment

Context: Recently, the United Nations General Assembly (UNGA) adopted a declaration recognising the cumulative and irreversible risks of sea-level rise and calling for stronger international cooperation, science-based adaptation and coordinated disaster-risk reduction. 

Best Online Coaching for UPSC

About the Declaration

• UNGA Adoption: The declaration was adopted by acclamation during the high-level segment of the 81st UN General Assembly on 24 September 2026.
• Science-Based Action: It calls for adaptation and mitigation based on the best available science and knowledge, with stronger coordination among UN specialised agencies.
• Global Observation: It supports coordinated scientific observation, data collection and exchange through the Global Ocean Observing System (GOOS) and Global Sea Level Observing System (GLOSS).
• Institutional Basis: The declaration builds on earlier UNGA action, including Decision 78/558 on “Enhancing action on sea-level rise”.

Its Significance

• Human Exposure: Around 770 million people live less than five metres above the high-tide line, making coastal populations particularly vulnerable.
• Economic Security: Rising seas threaten ports, infrastructure, agriculture, trade and coastal livelihoods.
• Threat Multiplier: Higher baseline sea levels intensify storm surges, cyclones, high tides, coastal flooding and erosion.
• Food and Water Security: Saltwater intrusion can contaminate freshwater aquifers and agricultural land, particularly in low-lying coastal areas.
• Disaster Risk Reduction: The declaration strengthens the focus on risk assessment, early warning, anticipatory action and long-term adaptation.
• Global Trade: Coastal disruption can affect ports, transport networks and supply chains, transmitting local climate risks into the wider global economy.

Geophysical Drivers for Sea Level Rise

• Ocean Warming: Rising ocean temperatures cause thermal expansion of seawater, contributing to long-term sea-level rise.
• Ice-Mass Loss: Melting of glaciers and Greenland and Antarctic ice sheets is an increasingly important contributor.
• Accelerating Trend: Global mean sea level has accelerated since satellite observations began in 1993 and was around 11 cm higher at the end of 2025 than in January 1993, according to the WMO State of the Global Climate 2025.
• Regional Variability: Local relative sea-level rise can be higher or lower than the global average because of factors such as land subsidence, uplift, ocean circulation and coastal geomorphology.

UPSC Course Fees Online

Challenges that need to be Addressed

• SIDS Vulnerability: Small Island Developing States (SIDS) face disproportionate risks to territory, freshwater, infrastructure, livelihoods and habitability.
• Maritime Governance: Sea-level rise raises questions concerning baselines, maritime zones and Exclusive Economic Zones (EEZs) under the United Nations Convention on the Law of the Sea (UNCLOS).
• Climate Displacement: Permanent inundation, erosion and salinisation can increase internal displacement and planned relocation pressures.
• Data Gaps: Vulnerable regions continue to face shortages of tide-gauge observations, local projections, technical capacity and interoperable data. The GLOSS Implementation Plan 2026, for instance, highlighted gaps in the global observing network.
• Adaptation Finance: Developing countries face significant gaps between adaptation needs and available international finance, limiting resilient infrastructure and planned adaptation.

Global Examples and Reports

• Bangladesh: The country’s Ganges-Brahmaputra-Meghna delta demonstrates the interaction of sea-level rise, river flooding, salinity and high population exposure.
• Small Island States: Saint Kitts and Nevis faces risks of saltwater intrusion into freshwater aquifers, while São Tomé and Príncipe face coastal erosion and salinisation.
• New York: The UNGA President’s address highlighted projections of substantial sea-level rise for New York City, illustrating risks even for advanced coastal cities.
• WMO State of the Global Climate 2025: Records the approximately 11 cm rise in global mean sea level since January 1993 and identifies sea-level rise as a key climate indicator.
• GLOSS Implementation Plan 2026: Highlights the importance of tide gauges, GNSS and satellite altimetry for sustained global sea-level monitoring.

India’s Relevance

• 1990–2018 – Coastal Erosion: The National Centre for Coastal Research (NCCR) assessed that 33.6% of India’s mainland coastline was under varying degrees of erosion, while 26.9% was accreting and 39.6% remained stable.
• 2019 – CRZ Framework: The Coastal Regulation Zone (CRZ) Notification, 2019 established a regulatory framework for development and conservation in ecologically sensitive coastal areas.
• 2020s – INCOIS Vulnerability Mapping: The Indian National Centre for Ocean Information Services (INCOIS) developed Coastal Vulnerability Index (CVI) maps based on parameters such as sea-level change, shoreline change, coastal elevation, slope, geomorphology, wave height and tidal range.
• 2020s – Coastal Risk Assessment: INCOIS undertook assessments of projected climate-change-induced extreme sea levels and coastal vulnerability at selected Indian locations.
• 2023 – MISHTI: The Mangrove Initiative for Shoreline Habitats & Tangible Incomes (MISHTI) was launched to promote mangrove restoration, strengthening nature-based coastal protection while supporting local livelihoods.

Way Forward

• Strengthen Observation and Data: Expand tide gauges, satellite altimetry and vertical land-motion monitoring, linking national observations with GOOS and GLOSS.
• Enhance Early Warning: Integrate INCOIS, meteorological observations and local vulnerability assessments into multi-hazard early-warning and anticipatory-action systems.
• Climate-Resilient Planning: Incorporate local sea-level projections into urban planning, ports, drainage systems, coastal infrastructure and land-use decisions.
• Scale Nature-Based Solutions: Expand mangrove, wetland and coral-reef restoration as natural buffers against coastal hazards.
• Strengthen Coastal Regulation: Integrate climate-risk and sea-level projections into Coastal Zone Management Plans and enforce risk-sensitive development norms.
• Mobilise Climate Finance: Improve access to adaptation finance, technology and capacity building, particularly for SIDS, Least Developed Countries and vulnerable coastal regions.

Click to Explore UPSC Offline Coaching

Conclusion

Sea-level rise is now a multi-dimensional threat to development, infrastructure, food security and maritime governance. The UNGA declaration calls for anticipatory, science-based and ecosystem-based coastal resilience through stronger international cooperation.

News Source: WMO

Check Out UPSC CSE Books

Visit PW Store