Climate-related litigation continues to expand worldwide, with courts increasingly treating climate action as a legal obligation rather than a political choice, according to the “Global Trends in Climate Change Litigation: 2026 Snapshot” released by the Grantham Research Institute on Climate Change.
The report shows that 249 new climate cases were filed globally in 2025, bringing the total number of climate lawsuits since 1986 to more than 3,600 across 62 countries.
The United States remains the most active jurisdiction, accounting for 151 new cases in 2025 and more than 2,000 cases overall.
The study notes that international courts, including the International Tribunal on the Law of the Sea (ITLOS), the Inter-American Court of Human Rights and the International Court of Justice (ICJ), have reinforced the view that governments have legal responsibilities to address climate change.
