NEW YORK / RankWire.AI / – United Nations Secretary-General António Guterres cautioned that the accelerating increase in sea levels heightens dangers for coastal populations and economies worldwide. He delivered these remarks during a UN General Assembly high-level session in New York on September 24. Guterres highlighted that approximately 770 million individuals reside less than five metres above the high-tide line. In 2024, the global average sea level rose by 5.9 millimetres, marking the highest annual rise ever recorded. The session concentrated on the threats confronting low-lying nations, coastal urban centers, and communities at risk.
The World Meteorological Organization has observed a notable acceleration in global sea-level increase during the satellite era. The annual growth rate climbed from 2.1 millimetres during 1993-2002 to 4.7 millimetres in 2015-2024. WMO data indicates that 2024 experienced the highest global mean sea level within the satellite record. Warming oceans cause seawater expansion, while melting glaciers and ice sheets add water to the oceans. These combined effects increase the vulnerability of coastal regions to flooding, erosion, and saltwater intrusion.
Projections from the Intergovernmental Panel on Climate Change suggest further rises across all assessed emissions pathways within this century. Under a very low emissions scenario, the global mean sea level may increase between 0.28 and 0.55 metres by 2100. Conversely, a very high emissions scenario estimates a likely range of 0.63 to 1.01 metres. These estimates are based on the average from 1995-2014 as the baseline. Guterres urged governments to cut emissions while enhancing efforts to shield communities from climate-related threats.
Sea-level rise accelerates globally
During the September 24 meeting, the General Assembly adopted a political declaration on sea-level rise through consensus. The declaration addresses scientific understanding, funding, resilience strategies, international cooperation, and legal concerns associated with rising seas. It emphasizes the need for stronger early-warning systems and more predictable financing for vulnerable nations. General Assembly President Khalilur Rahman highlighted the rapid pace of global sea-level rise during the session, noting that ports handle more than 80% of international merchandise trade, thereby linking coastal risks to global supply chains.
Special attention focused on small island developing states and low-lying coastal zones, which face severe threats from rising seas. Such increases can damage homes, roads, power infrastructure, farmland, and freshwater supplies, while also stressing coastal ecosystems. The declaration also considers risks to livelihoods, cultural heritage, and communities experiencing recurrent coastal flooding. Countries discussed international cooperation as they respond to the physical and legal consequences of changing coastlines. This meeting followed a 2024 decision by the General Assembly to bolster international efforts against sea-level rise.
UN emphasizes resilience and climate mitigation in new declaration
Guterres called for action in three key areas: reducing emissions, safeguarding communities, and closing legal gaps caused by rising seas. He advocated for accelerated deployment of renewable energy and enhanced energy efficiency measures as part of global emission reduction strategies. Adaptation efforts should include resilient infrastructure, effective warning systems, and support for vulnerable coastal populations. The United Nations has recognized sea-level rise as a significant obstacle to development, food security, and economic stability. Coastal impacts can also hinder transport networks and disrupt international commerce.
Scientific evaluations forecast continued sea-level rise throughout the 21st century as oceans warm and land-based ice melts. According to the IPCC, sea levels will keep rising for centuries to millennia because both oceans and ice sheets react slowly to climate warming. The WMO has also issued warnings that ocean warming and sea-level rise could produce effects lasting hundreds of years. The new UN declaration offers a unified framework covering resilience, financial support, scientific understanding, and international legal frameworks. Its adoption underscores the prominence of sea-level rise among core climate issues addressed during the General Assembly’s 2026 high-level meetings.