The International Court of Justice (ICJ) issued its landmark advisory opinion on climate change in July
2025 (the AO), following a request by the UN General Assembly to clarify States’ legal duties to protect
the climate system and the consequences of causing climate harm. A UN General Assembly Resolution
to welcome and operationalise the AO was adopted in May 2026 with 141 States voting in favour, with
only 8 against, and 28 abstentions, reflecting the opinion’s international authority.
The AO equips negotiators with a strong legal basis to advance their positions and negotiate decisions
that align with international law. Adopted unanimously by the ICJ judges, it provides an authoritative
interpretation of States’ existing legal obligations regarding climate change; it does not create new law.