ICJ Issues Climate Change Advisory Opinion on States' Duties

Climate activists voice their opinion outside the International Court of Justice (ICJ) in The Hague.

The International Court of Justice (ICJ) in The Hague, Netherlands, issued its advisory opinion on the obligations of states regarding climate change, as read out by the President of the Court, Judge Iwasawa Yuji, on Wednesday.

The UN’s principal judicial body ruled that states have an obligation to protect the environment from greenhouse gas (GHG) emissions and must act with due diligence and cooperation to fulfil this obligation.

This includes the commitment under the Paris Agreement on climate change to limit global warming to 1.5°C above pre-industrial levels.

The Court further ruled that if states breach these obligations, they incur legal responsibility and may be required to cease the wrongful conduct, offer guarantees of non-repetition, and make full reparation depending on the circumstances.

The Court based its reasoning on Member States’ commitments to both environmental and human rights treaties.

Firstly, Member States are parties to a variety of environmental treaties – including those on the ozone layer, the Biodiversity Convention, the Kyoto Protocol, the Paris Agreement, and many more – which oblige them to protect the environment for people worldwide and future generations.

Additionally, because “a clean, healthy and sustainable environment is a precondition for the enjoyment of many human rights,” and since Member States are parties to numerous human rights treaties – including the UN’s Universal Declaration of Human Rights – they are required to ensure the enjoyment of such rights by addressing climate change.

In September 2021, the Pacific Island state of Vanuatu announced that it would seek an advisory opinion from the Court on climate change. This initiative was inspired by the youth group Pacific Island Students Fighting Climate Change, which underscored the need to act, particularly in small island states.

After lobbying other UN Member States, the General Assembly adopted a resolution on 29 March 2023 requesting an advisory opinion from the ICJ on two questions:

What are the obligations of states under international law to ensure the protection of the environment?

What are the legal consequences for states under these obligations when they cause harm to the environment?

The UN Charter allows the General Assembly or the Security Council to request the ICJ to provide an advisory opinion. Although such opinions are not legally binding, they carry significant legal and moral authority and help clarify and develop international law by defining states’ legal obligations.

This is the largest case ever seen by the ICJ, based on the number of written statements (91) and states that participated in oral proceedings (97).

The ICJ, informally known as the “world court”, settles legal disputes between UN Member States and gives advisory opinions on legal questions referred to it by UN organs and agencies.

It is one of the six principal organs of the UN – alongside the General Assembly, the Security Council, the Economic and Social Council (ECOSOC), the Trusteeship Council, and the Secretariat – and is the only one not based in New York.