By Dr Eugenia Recio, University of Eastern Finland

As the climate crisis intensifies, UN Secretary-General António Guterres warns we have transitioned from global warming to “global boiling.” International agreements like the 1992 UNFCCC and the 2015 Paris Agreement demonstrate a collective intent to address the climate emergency. Yet, there remains a gap between projected emissions and the emission reduction targets that science requires to prevent the most severe climate impacts, with emissions predicted to exceed 2010 levels by 9% in 2030. The UN General Assembly (UNGA) has requested an advisory opinion from the International Court of Justice (ICJ) to clarify the responsibilities of States in safeguarding the climate for current and future generations. This policy brief explores how other international courts might inform the ICJ’s stance on climate-related State obligations.

The UN Convention on the Law of the Sea (UNCLOS) defines how nations should use and protect the oceans. While it does not directly address climate change, it sets a general obligation of States to protect and preserve the marine environment, along with provisions concerning the prevention, reduction, and control of pollution of the marine environment (UNCLOS Part XII, particularly articles 192 and 194). In 2019, the Intergovernmental Panel on Climate Change (IPCC) issued a report stating linkages and negative effects of climate change on the ocean, including ocean warming, sea level rise, and ocean acidification. Greenhouse gases (GHGs) could therefore fall within the definition of marine polution in UNCLOS.

The International Tribunal for the Law of the Sea (ITLOS) serves as a judicial body to adjudicate maritime disputes and interpret UNCLOS provisions. On 12 December 2022, the Commission of Small Island States on Climtate Change and International Law (COSIS) submitted a request for an advisory opinion to ITLOS. The request asks the Tribunal to clarify the specific obligations of States under UNCLOS to prevent, reduce, and control pollution of the marine environment in relation to climate change.

Addressing COSIS’ request, ITLOS gathered a wide range of perspectives from States and organizations by 16 June 2023. Fifty-three submissions reveal differing views on the allocation of responsibility. While some advocate for collective mitigation obligations, including GHG emissions reduction, others argue that UNCLOS should reflect differentiated responsibilities and capabilities – a principle reflected in the UNFCCC. Yet, some posit that specific climate change obligations should remain under the ambit of existing climate agreements rather than be dealt with under UNCLOS.

Public hearings started on 11 September 2023, and the advisory opinion is expected to be released on 21 May 2024. Although not legally binding, an advisory opinion does have legal authoritative effects. Its delivery will be one of the first times an international court addresses the legal interplay between States’ responsibilities concerning climate change, the marine environment, and small island States.

The increasing awareness of how climate change affects human rights calls for clear definitions of State responsibilities. The Inter-American System on Human Rights has played a pivotal role in framing climate change as a critical matter of rights protection. In 2017, to address a request by Colombia, the Interamerican Court on Human Rights (IACtHR) issued an advisory opinion recognizing the right to a healthy environment as a human right. Additionally, it acknowledged the extraterritorial obligations of States under the American Convention on Human Rights, opening a legal pathway for individuals to seek recourse against States for environmental harm across borders, including climate-related damages.

More recently, in 2023, Chile and Colombia submitted to the IACtHR a request for an advisory opinion. The request seeks to “clarify the scope of State obligations, in its individual and collective dimension, to respond to the climate emergency.” The applicants inquired into the nature of State responsibilities in managing climate emergencies, particularly the duty to prevent and mitigate the impacts on human rights, actions to comply with the Paris Agreement, adaptation and mitigation measures, and the management of climate-induced loss and damage. Other issues raised in the request concern: duties inherent to the right to life; the rights of children and new generations; and States’ common but differentiated responsibilities.

The Court extended an invitation to stakeholders to contribute with observations. The submission period, initially closing on 18 August, was extended twice – first to 18 October and finally to 18 December 2023. This extension led to a diverse array of inputs, including from nine States. Workshops for non-governmental organizations (NGOs) and civil society, including for children, are being held in Barbados, from 23-25 April 2024, and in Brazil, on 24 May and from 27-29 May. With one of the most inclusive participation efforts by any international tribunal, the Court garnered over 265 submissions representing over a thousand individuals and entities, setting the stage for an advisory opinion that is expected to leave a strong legal footprint.

On 9 April 2024, the European Court of Human Rights (ECtHR) also set an important precedent that binds all European Courts by delivering three key rulings on climate change and human rights. In the case of Verein KlimaSeniorinnen Schweiz and Others v. Switzerland, the Court ruled that States are obligated to shield individuals from adverse effects of climate change and that States’ climate policies are subject to human rights standards, requiring effective and timely measures to protect individual rights.

The proceedings before ITLOS, the ECtHR, and the IACtHR show the growing need to clarify responsibilities of States to catalyze climate action. Some of the emergent trends include the recognition of a diverse range of claimants, the acknowledgment of the link between the enjoyment of fundamental rights and climate change mitigation and adaptation measures, and the opening of participation in the proceedings to a wide variety of stakeholders. Although not binding on the ICJ, the outcomes of these proceedings, if delivered before the beginning of 2025, might exert an influence on the anticipated ICJ advisory decision. More importantly perhaps, these proceedings reveal an urgent need for legal clarity the ICJ opinion is expected to deliver.

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This Policy Brief is part of a project that seeks to raise awareness and build momentum and knowledge around the ICJ advisory opinion on obligations of States in respect of climate change and to promote a better understanding of the implications of the advisory opinion among sustainable development decision makers. This work is funded by the Foundation for International Law for the Environment (FILE).