SYLLABUS

GS-2: Important International Institutions, Agencies, and Fora—Their Structure and Mandate.

GS-3: Conservation; Disaster and disaster management.

Context: The UN General Assembly (UNGA) recently adopted the UN Declaration on Sea-Level Rise during its 81st session, recognising sea-level rise as an accelerating global challenge requiring coordinated international action.

More on the News

• First UN declaration specifically on sea-level rise: The Political Declaration brings together climate, development, disaster-risk reduction, human rights and international-law dimensions.
• Nature and framework: It is a political declaration that reinforces existing frameworks, particularly UNCLOS, UNFCCC and the Paris Agreement, rather than creating a new treaty.
• SIDS leadership: It recognises decades of advocacy by Small Island Developing States (SIDS) and refers to the 1989 Malé Declaration, the 2021 and 2023 Pacific Islands Forum declarations, and the 2021 and 2024 Alliance of Small Island States (AOSIS) declarations.

Understanding Sea-Level Rise

Why is Sea Level Rising?

• Sea-level rise (SLR) is the long-term increase in the average level of the world's oceans. The present rise is primarily driven by global warming, through two major processes:
  Thermal expansion: Oceans absorb much of the excess heat from global warming; as seawater warms, it expands and occupies greater volume.
  Melting of land-based ice: Warming accelerates the melting of glaciers and ice sheets, adding freshwater to the oceans.
• The Declaration similarly identifies ocean warming and melting ice sheets and glaciers as the primary drivers and notes that the phenomenon is accelerating.

Current Trend and Key Data

• Global mean sea level rose by an average of 4.7 mm per year during 2014–2023, while the annual rise reached 5.9 mm in 2024, the highest annual increase recorded.
• By the end of 2025, global mean sea level was around 11 cm higher than in January 1993, when the satellite record began, demonstrating the long-term acceleration of the trend.
• Around 770 million people, or nearly one-tenth of humanity, live in coastal areas less than five metres above the high-tide line, making them particularly exposed to rising seas.
• Without significant adaptation and mitigation, risks facing coastal cities and communities are projected to increase at least tenfold by 2100.

Impacts of Sea-Level Rise

• Physical and environmental: Increased coastal flooding, storm surges, erosion, permanent inundation, loss of habitable land and degradation of coastal ecosystems.
• Water and food security: Saltwater intrusion can contaminate freshwater sources and agricultural land, while impacts on coastal ecosystems affect fisheries and aquatic food systems.
• Economic and infrastructure: Rising seas threaten buildings, ports, transport networks, energy and water systems, healthcare facilities, tourism and insurance markets. The UN report estimates that existing coastal infrastructure damage has exceeded $1.8 trillion.
• Human rights and displacement: Risks extend to adequate housing, safe drinking water, sanitation, food, health and education. Without urgent adaptation, up to 1.2 billion people could face displacement by 2050, according to the UN special report.

Key Highlights of the Declaration

• Knowledge, data and early warning: Calls for stronger scientific observation, data collection, modelling, risk assessments and multi-hazard early-warning systems, including through the Global Ocean Observing System and Global Sea Level Observing System. It also recognises traditional, Indigenous and local knowledge and calls for capacity-building and technology transfer.
• Adaptation, finance and resilience: Calls for enhanced public and private finance, particularly for developing countries, SIDS and LDCs; timely and predictable access to finance; nature-based solutions; and integration of SLR projections into critical infrastructure planning.
• Livelihoods, human mobility and cultural heritage: Seeks to integrate SLR risks into social protection and national development planning and recognises its implications for livelihoods, ocean-based economic activities, vulnerable groups, cultural heritage and human mobility.
• Maritime zones: Affirms that once established under UNCLOS, States can maintain their maritime zones despite physical changes resulting from SLR, while retaining the ability to update them.
• Continuity of statehood: Affirms a presumption in favour of continued statehood and recognises continuity of statehood, sovereignty, sovereign rights and responsibilities, and UN membership, consistent with international law.
• Human rights and legal dimensions: Emphasises legal stability, certainty and predictability, takes note of the 2025 ICJ Advisory Opinion on the Obligations of States in respect of climate change and calls for protection of persons affected by SLR.

Significance of the Declaration

• Makes SLR a multidimensional governance issue: Connects climate change with adaptation, disaster risk reduction, finance, development, human rights and international law, rather than treating it only as an environmental problem.
• Provides greater certainty for island states: Its positions on maritime zones and continued statehood address major legal concerns arising from physical changes to island territories. This is particularly significant for SIDS.
• Strengthens anticipatory action: Emphasis on observation, risk assessment, early warning and long-term planning can shift responses from post-disaster relief towards preparedness and resilience.
• Protects development and human well-being: The Declaration recognises that SLR can erode development gains and affect livelihoods, infrastructure, health, food systems and cultural heritage, particularly in vulnerable developing countries.

Challenges

• Implementation gap: Translating the Declaration's political commitments and principles into national policies, financing and coordinated international action will require sustained implementation.
• Large adaptation-finance gap: Developing countries are estimated to need $310–365 billion annually for adaptation by 2035, while international public adaptation finance stood at only $26 billion in 2023.
• Scientific and capacity constraints: Significant gaps remain in sustained ocean observations, data and risk-assessment capacity, particularly in oceans, SIDS and vulnerable coastal regions.
• Legal protection cannot prevent physical impacts: Continuity of statehood and stability of maritime zones do not eliminate land loss, inundation, ecosystem degradation, displacement or threats to habitability.

Way Forward

• Strengthen science-led adaptation: Expand sustained ocean observation, modelling, risk assessment, climate information and multi-hazard early-warning systems, especially in vulnerable regions.
• Bridge the finance and capacity gap: Provide adequate, predictable and simplified access to adaptation finance, technology transfer and capacity-building for developing countries, particularly SIDS and LDCs.
• Build resilient and people-centred coasts: Integrate SLR projections into infrastructure and development planning, combine engineered measures with nature-based solutions, and protect livelihoods, human rights and cultural heritage.
• Ensure sustained international follow-up: Translate the Declaration's principles on maritime zones, statehood, human mobility and institutional support into practical action, while continuing multilateral coordination.