This opinion critically analyses the ‘advisory opinion’ of the International Court of Justice (ICJ) which concerns the obligations of States in respect of climate change (2025), and in doing so, identifies issues that remain unresolved with the advisory opinion. This opinion also considers the principle of erga omnes, which is briefly mentioned in the ‘advisory opinion’ and also discusses climate change obligations that have the character of erga omnes, that is, obligations that are owed by a State to members of the international community as a whole. It is suggested that the ICJ has missed opportunities to clarify the relationship between the obligation(s) concerning climate change, the principle of erga omnes, consent and customary international law. It is also argued that the list of obligations that were considered jus cogens by the International Law Commission could be expanded, in the context of climate change, and notes that these types of obligations are also owed to members of the international community as a whole (erga omnes).
