World leaders at the United Nations have approved the first-ever declaration on sea level rise. The General Assembly adopted it by consensus at a high-level meeting in New York in late September. The United States did not block it.

That made the outcome a rare win for multilateral climate action. The declaration sets out how the world will handle rising seas. Its most striking feature concerns island nations.

Under the agreement, low-lying states will continue to exist as political entities even if their land disappears under water. Some island nations face near-total inundation over the coming century. Melting ice sheets and glaciers are pushing seas higher.

The text also refers to climate change and climate aid for developing countries. The deal matters because global climate cooperation has been under strain. The US left the Paris agreement in President Trump’s second term.

Washington also opposed a carbon tax on cargo ships. Against that backdrop, a unanimous text with climate references stands out. For island states, the declaration offers legal and political security.

Their statehood, maritime zones and rights will survive even as the seas rise.