Advisory opinion

A court’s answer to a legal question put to it by a body entitled to ask, rather than a ruling in a dispute between parties. It sets out the court’s view of what the law requires and is authoritative, but it does not bind states in the way a judgment binds the parties to a case.

Why it matters in the room

Three international courts have answered questions on climate change: the International Tribunal for the Law of the Sea (21 May 2024), the Inter-American Court of Human Rights (OC-32/25, dated 29 May 2025 and made public on 3 July 2025) and the International Court of Justice (23 July 2025). Their reading of what states owe under existing law is now part of the legal background to talks on NDCs (as of October 2026).