ICJ issues advisory opinion on climate change obligations

THE HAGUE - The International Court of Justice (ICJ) on Wednesday delivered here its advisory opinion on the legal obligations of states concerning climate change, following a request from the UN General Assembly.

The advisory opinion, read out by ICJ President Yuji Iwasawa in a public session, said that key climate treaties, including the UN Framework Convention on Climate Change, the Kyoto Protocol, and the Paris Agreement, impose "binding obligations" on state parties.

The obligations include taking measures to mitigate greenhouse gas emissions, adapt to climate change, cooperate under the principle of common but differentiated responsibilities and respective capabilities, and fulfill commitments on finance and technology transfer.

The ICJ further stated that "customary international law" obliges states to "ensure the protection of the climate system and other parts of the environment from anthropogenic greenhouse gas emissions".

"States have a duty to prevent significant harm to the environment by acting with due diligence ... in accordance with their common but differentiated responsibilities and respective capabilities," it said.

The court also emphasized that similar obligations arise under other treaties such as the Vienna Convention for the Protection of the Ozone Layer, the Convention on Biological Diversity, the UN Convention to Combat Desertification, and the UN Convention on the Law of the Sea. International human rights law also requires states to protect the climate and environment to ensure the enjoyment of human rights.

The court said that "a breach" by a state of these obligations constitutes "an internationally wrongful act entailing the responsibility of that state". This includes the duties to cease the wrongful act, prevent its recurrence, and make reparation under preconditions including "a sufficiently direct and certain causal nexus can be shown between the wrongful act and injury".

The ICJ issued this non-binding advisory opinion at the request of the UN General Assembly. On March 29, 2023, the UN General Assembly adopted a resolution requesting the court to provide an advisory opinion on legal obligations related to climate change, focusing on two core issues: first, the international legal obligations of states in protecting the climate system and the environment; and second, the legal consequences arising from a state's failure to fulfill those obligations.