In every scenario, several mega-cities across continents face escalating dangers from rising sea levels. Prominent urban centers like Cairo, Lagos, Maputo, Bangkok, Dhaka, Jakarta, Mumbai, Shanghai, Copenhagen, London, Los Angeles, New York, Buenos Aires, and Santiago are cited as being at heightened risk, according to the Secretary-General of the United Nations. The remarks were delivered in a Security Council session focused on the peace and security implications of sea level rise (at the United Nations, 2024 update).
This concern was voiced during a Security Council meeting convened to assess how climate impacts are shaping global stability and national security in the United States and beyond. The Secretary-General emphasized that the pace of sea level rise has accelerated in recent decades, marking this era as exceptionally climate-sensitive compared with any period in the last 3,000 years. He framed the trend as both a direct hazard and a catalyst that intensifies other threats, already generating new forms of instability and conflict around the world.
Rising waters threaten not only lives but also vital access to water, food, and essential medical services. Saltwater intrusion threatens agricultural lands, fisheries, and coastal tourism, potentially erasing entire regional economies and undermining livelihoods in vulnerable sectors.
The Secretary-General noted that for certain communities and nations, the problem is acute and may worsen if the most dire forecasts from scientific bodies come true.
All countries may perish
The combination of sea level rise and saltwater intrusion risks rendering some of the world’s largest river deltas uninhabitable. Examples include the Mekong Delta in Southeast Asia and the Ganges-Brahmaputra delta in South Asia, where millions depend on deltaic ecosystems for food, water, and income.
The Secretary-General warned that low-lying communities and entire nations could face permanent displacement. He described a future shaped by large-scale migrations, intensified competition for fresh water, land, and other essential resources, and the potential for renewed regional tensions.
He stressed that the danger is greatest for nearly 900 million people living in vulnerable coastal zones, a figure he framed as roughly one in every ten people worldwide.
To address these grave risks, the international community was urged to act decisively in three interlocking areas: sharply reduce global warming, protect the most at-risk communities, and reform international law to safeguard those displaced by climate impacts. The call was for practical measures that can curb emissions, strengthen resilience, and provide fair, humane protection for climate migrants.
In short, the message was clear: without urgent, coordinated action, sea level rise will continue to reshape both the map of human settlements and the fabric of global security. The moment demands not only scientific clarity but political will and collaborative diplomacy to safeguard communities, economies, and futures around the world. The emphasis remains on mitigation, adaptation, and inclusive legal frameworks that recognize and defend the rights of the displaced.