The prime ministers of two small island nations that face ongoing impacts from rising sea levels will appear at legal hearings at an international court in Hamburg, Germany, on Monday, and seek an advisory opinion on the obligations of countries to combat climate change.

Prime Ministers Kausea Natano of Tuvalu and Gaston Browne of Antigua and Barbuda will give evidence at the International Tribunal for the Law of the Sea, which will consider whether carbon emissions absorbed by the ocean should be considered marine pollution, and what obligations nations have to protect the marine environment.

The tribunal will issue an advisory opinion, which is not legally binding, but offers an authoritative statement on legal matters that could guide countries as they craft climate protection law.

The prime ministers, representing the Commission of Small Island States on Climate Change and International Law (COSIS), will argue that countries have an obligation to protect the marine environment under the UN convention on the Law of the Sea, including from greenhouse gas emissions.

“We come here seeking urgent help, in the strong belief that international law is an essential mechanism for correcting the manifest injustice that our people are suffering as a result of climate change," said Tuvalu's Natano.

Excessive carbon pollution results in damage to the oceans, including coral bleaching and acidification.

Low-lying island states like Tuvalu and Vanuatu are also at risk of becoming submerged by water by the end of the century due to slow-onset climate impacts.

Small island nations have also sought legal clarity on nations' climate obligations in other courts. Vanuatu led a campaign to ask the International Court of Justice (ICJ) to issue an advisory opinion on countries' obligations to address climate change.

The UN General Assembly in March voted to refer the case to the ICJ, which will issue an opinion in 2024.