The International Tribunal for the Law of the Sea declared that excessive greenhouse gases are pollutants causing irreversible harm to the marine environment. This non-binding but unanimous opinion could lead to broader claims for damages against polluting nations. The tribunal stated that nations are legally obligated to take necessary measures to reduce, control, and prevent marine pollution from human-made greenhouse gas emissions. This ruling could influence how other courts address the dangers posed by these gases. The opinion expands the definition of marine pollution to include greenhouse gases, a concept not addressed in the 1970s United Nations Convention on the Law of the Sea. Small island nations, impacted by rising sea levels, sought this advisory opinion, arguing that existing climate accords have not done enough to prevent lasting damage to the oceans. Despite opposition from major polluters, the tribunal asserted its jurisdiction to set new rules.