Island Nations Hope for Court’s Help on Climate’s Effects

A group of small island nations threatened by frequent storms and rising seas is for the first time appearing before an international court to seek its help, hoping for a decision that excessive greenhouse gases are pollutants that violate international law.

If the group’s request is successful, the court’s opinion could lead to wide-ranging claims for damages.

Hearings in the case opened on Monday at the request of nine Pacific and Caribbean island nations that have joined. The sessions at the International Tribunal for the Law of the Sea in Hamburg, Germany, are expected to last for two weeks and have drawn wide attention.

Representatives of more than 40 countries, including large emitters of greenhouse gases including China, India and members of the European Union, have asked to participate via oral or written interventions. Arguments will revolve around the 1982 United Nations Convention on the Law of the Sea, the legal framework that covers uses of the oceans and their resources, including the obligation to protect the marine environment. The convention has been ratified by 168 nations, although the United States is not one of them.

But the convention, negotiated in the 1970s, does not mention emissions of greenhouse gases and their effects on the warming and acidification of the oceans, and on sea-level rise.

For the tribunal, this will be a test case: The Oceans Court, as it is also called, has ruled on issues like fisheries, rights of passage, and seabed mining and pollution, but it has never heard a case on greenhouse gases and their impact on climate change and the oceans.

Leaders of the island nations argue that they did not create the problems and account for only 1 percent of carbon emissions but bear the catastrophic effects. Some atolls have already disappeared underwater, coasts are eroding, and some land has become uninhabitable as fresh water for drinking and planting crops has turned saline. They believe broader disaster looms.

At this stage, the island nations are not suing for damages but are seeking a so-called advisory opinion on what legal obligations countries have to prevent damaging the oceans. The key question is whether the judges, as they interpret the law on protection, will take into account the broad scientific consensus on the impact of greenhouse gases on the climate and the marine environment.

Experts say the answer could affect claims for damages in both international and national courts.

If the judges conclude that the causes of ocean warming can be defined as marine pollution, Alan Boyle, an emeritus professor of international law at the University of Edinburgh, has said that “would open the way to bringing successful proceedings for claims here or in other international courts.”

“The islands could hold major emitters of greenhouse gases responsible for damage by their failure to implement the Paris climate accord,” he said.

Experts say the tribunal’s opinion could also affect national jurisdictions, where activists are increasingly taking on governments and coal, oil and gas companies for climate damage and have achieved successes in several countries, including Australia, Germany and the Netherlands.

The problems of the island states vary: Volcanic islands in the Caribbean have suffered infrastructure damage because of the growing number of hurricanes. Low-lying atolls, mainly in the Pacific, have lost landmass from erosion and flooding, and fresh water for crops and drinking because of salinity. Some residents have had to move elsewhere.

David Freestone, who co-wrote a 2021 World Bank report on the legal dimensions of sea-level rise, said the tribunal could also clarify other crucial questions stemming from the radical impacts of changes in the oceans.

Countries are asking how the range of their territorial waters is affected when land is eroded or goes underwater. Low-lying islands may shrink or expand. And, Mr. Freestone said, they are asking about their vast exclusive economic zones and vital fishing rights. “After much debate, the jury is still out,” he said. “An authoritative modern tribunal of Law of the Sea specialists could clarify such ambiguities.”

The group of small islands pleading before the Hamburg tribunal has also asked the International Court of Justice to weigh in on what legal obligations governments have “in respect of climate change” and what the consequences might be if they failed to meet those obligations.

Lawyers believe that the judges in Hamburg will respond first, perhaps within a few months, and that their opinion will carry special weight because of their expertise as judges on the Law of the Sea tribunal.