The world's highest court covering the oceans said Tuesday that excessive greenhouse gases are pollutants that can cause irreversible damage to the marine environment. The groundbreaking advisory opinion was unanimous, and experts say it could lead to broader damages claims against polluting nations.
The opinion of the court, the International Tribunal for the Law of the Sea, is not binding, but states that from a legal perspective, nations must take all necessary measures to reduce, control and prevent marine pollution caused by gas emissions man-made greenhouse.
Given the jurisdiction of the Court, sometimes called the Court of Oceans, the opinion is likely to influence how other international and national courts address the growing dangers posed by greenhouse gases that cause ocean warming and acidification.
As the world warms, the oceans absorb a significant amount of the excess heat, which has the potential to alter ocean currents and the marine ecosystem and contribute to coral bleaching, among other dangers. Acidification, which is also harmful to marine life and can alter marine food webs, occurs when ocean waters absorb carbon dioxide, the main greenhouse gas warming the world.
The request for an advisory opinion was made by a group of small island nations already affected by rising sea levels. The Court's opinion applies to the more than 165 countries that have ratified the United Nations Convention on the Law of the Sea, which includes major polluters such as China, Russia and India, but not the United States.
The opinion issued Tuesday by the 21 justices effectively expanded the definition of marine pollution to include greenhouse gases. The convention, negotiated in the 1970s, does not mention these emissions and their adverse effects on the world's oceans, which is based on more recent scientific data.
“We didn't know how bad these emissions were in the 1970s,” said David Freestone, co-author of a 2023 World Bank report on the legal dimension of sea level rise that followed court hearings and arguments. “At the time, people were worried about acid rain.”
The key questions addressed by the court were whether excessive greenhouse gases constituted “pollution of the marine environment” – the justices said yes; and if countries can be held accountable – again, yes.
The leaders of the island nations who sued argue that existing climate agreements have not made enough progress to prevent lasting damage to the oceans. They say that although they contribute only a small part to global emissions, they are already bearing the brunt of the catastrophic effects of climate change.
“This is truly an epic race between David and Goliath,” Payam Akhavan, the lead attorney for the group prosecuting the case, said at a recent news conference. He said some of the world's smaller nations are invoking the power of international law against big polluters.
China and Saudi Arabia, a major oil exporter, strongly contested the islands' request during hearings in the case last year, saying the court did not have sufficient authority to set new rules. But the justices said Tuesday that the court had jurisdiction.