NEW YORK / RankWire.AI / – United Nations Secretary-General António Guterres issued a warning that the rapid acceleration of sea-level rise poses increasing dangers for coastal communities and economies across the globe. Speaking during a high-level session at the UN General Assembly in New York on September 24, Guterres emphasized that approximately 770 million individuals reside less than five metres above the high-tide line. The year 2024 saw the highest annual global mean sea level increase on record, with a rise of 5.9 millimetres. The gathering emphasized the risks faced by low-lying nations, coastal urban centers, and vulnerable populations.
The World Meteorological Organization has documented a notable acceleration in worldwide sea-level rise during the satellite observation era. The rate of increase climbed from 2.1 millimetres per year in 1993-2002 to 4.7 millimetres per year in 2015-2024. Data from WMO indicate that 2024 registered the highest global mean sea level within the satellite record. The warming of oceans leads to water expansion, while melting glaciers and ice sheets contribute additional water to the seas. These combined processes heighten the risks of coastal flooding, erosion, and saltwater intrusion.
Projections from the Intergovernmental Panel on Climate Change (IPCC) indicate further increases in sea levels across all assessed emissions scenarios this century. Under a very low emissions pathway, global mean sea level could rise between 0.28 to 0.55 metres by 2100, whereas a very high emissions pathway may see rises from 0.63 to 1.01 metres. These estimates are based on the 1995-2014 average as a reference. Guterres called on governments to reduce emissions and simultaneously implement measures to shield communities from climate-related hazards.
Worldwide acceleration of sea-level rise
During the September 24 gathering, the General Assembly adopted a political declaration on sea-level rise through consensus. This declaration addresses the scientific understanding, financing challenges, resilience strategies, international cooperation, and legal issues related to rising seas. It emphasizes the need for enhanced early-warning systems and more predictable financial support for at-risk nations. Highlighting the urgency, General Assembly President Khalilur Rahman pointed out the increasing pace of global sea-level rise during the session. He also underscored that ports facilitate over 80% of global merchandise trade, linking coastal risks directly to international supply chains.
Special attention was given to small island developing states and low-lying coastal regions, which face significant threats from rising waters. Such increases threaten homes, roads, electrical infrastructure, agriculture, and freshwater supplies, while also putting pressure on coastal ecosystems. The declaration also considers risks to livelihoods, cultural sites, and communities repeatedly affected by coastal flooding. Discussions centered on international cooperation as nations confront the physical and legal repercussions of evolving coastlines. This meeting follows a 2024 decision by the General Assembly to bolster global efforts against sea-level rise.
UN focus on resilience and climate mitigation strategies
Guterres urged action across three key areas: reducing greenhouse gas emissions, safeguarding communities, and closing legal gaps created by rising seas. He emphasized the importance of expanding renewable energy sources and improving energy efficiency as part of global efforts to cut emissions. Effective adaptation strategies include resilient infrastructure, reliable warning systems, and support for communities increasingly exposed to coastal hazards. The United Nations recognizes sea-level rise as a major obstacle to development, food security, and economic stability. Disruptions caused by rising seas can also impact transportation networks and international trade.
Scientific evaluations predict that sea levels will continue to climb throughout the 21st century as ocean temperatures rise and land-based ice melts. The IPCC notes that sea-level rise will persist for centuries to millennia because oceans and ice sheets respond slowly to warming. Additionally, WMO has warned that ocean warming and sea-level rise produce effects that may last for hundreds of years. The new UN declaration offers a unified approach addressing resilience, financial support, scientific research, and international legal frameworks. Its adoption elevates sea-level rise as a core issue in the climate agenda during the UN General Assembly’s high-level meetings in 2026.