International Tribunal for the Law of the Sea Advisory Opinion on Climate Change and International Law Led by Small Island State Leaders

On May 21, 2024, the International Tribunal for the Law of the Sea (ITLOS) delivered its Advisory Opinion on climate change and international law, in a case led by two courageous leaders of Small Island States, Prime Minister Gaston Browne of Antigua and Barbuda and former Prime Minister Kausea Natano of Tuvalu.

ITLOS is an international court established under the United Nations Convention on the Law of the Sea (UNCLOS). It adjudicates disputes arising out of the interpretation and application of UNCLOS. The tribunal has jurisdiction over a wide range of maritime issues, including the protection and preservation of the marine environment, and it has the discretionary authority to issue advisory opinions.

In 2021, at the COP Meeting in Glasgow, Browne and Natano, frustrated by the grindingly slow pace of countries to make substantial progress to curb Climate Change or to address its impacts on small islands, which are greatest victims while being the least perpetrators, decided to move outside the COP to seek justice in international law. The two leaders co-founded the Commission of Small Island States on Climate Change and International Law (COSIS) as a vehicle for safeguarding the legal rights of their countries and their survival.

COSIS assembled a group of international and experienced lawyers, headed by Professor Payam Akhavan to plead the case before ITLOS. Regrettably, despite approaches to all small island states, only seven others joined COSIS. The seven that joined were Palau, Naru, The Bahamas, Vanuatu, St. Kitts and Nevis, St. Vincent and the Grenadines, and St. Lucia.

Nonetheless, Browne and Natano persisted. They established COSIS as an international organization with the UN and established Antigua and Barbuda as the depository for the treaty. By December 2022, COSIS submitted its request to ITLOS, essentially seeking an advisory opinion on the specific obligations of States, regarding the prevention, reduction, and control of marine environmental pollution stemming from climate change, as well as the protection and preservation of the marine environment in the context of climate change impacts.

These matters have significantly impacted small island states. Scientific evidence shows that climate change—caused by CO2 emissions from the world’s largest industrial nations—has repeatedly and severely damaged them.

There is little doubt that the stalled negotiations at COP concerning compensation for ‘loss and damage’ garnered a new momentum at the meeting in 2022, precisely because of the COSIS case before ITLOS which attracted the defensive participation of many of the big polluting nations. The sudden, but severely limited decision at COP in 2022 to establish a Committee to examine the modalities for a Fund, was an effort to stave off further legal action by SIDS. As it turned out, the COP meeting in 2023, received insufficient pledges to ensure the fund’s success.

The cost of loss and damage for developing countries is projected to reach $400 billion per year by 2030 and the initial pledges made at COP28 are considered paltry in comparison to the scale of the challenge. Furthermore, the definition of “vulnerability” and the eligibility criteria for accessing the fund are still being negotiated.

In any case, the ITLOS unanimous Advisory Opinion is a game changer. It is a significant event in the legal landscape related to climate change precisely because it will shape actions around climate change at both the international legal level and within the corporate sector. It will immediately affect the 168 States that are Parties to UNCLOS, but even states that are not party to UNCLOS, such as the US, recognize many of its provisions as forming part of customary international law.

The Advisory Opinion delivered by ITLOS includes several critical points. It concluded that States Parties to the UNCLOS Convention have specific obligations under article 194 “to take all necessary measures to prevent, reduce, and control marine pollution from anthropogenic GHG emissions and to endeavour to harmonize their policies in this connection”; provides guidance as to states’ obligations in relation to climate change under UNCLOS; found that states have a due diligence obligation to protect and preserve the marine environment from the deleterious effects of climate change; the obligations of states to assist developing states; and affirms that where there are threats of serious or irreversible damage, lack of full scientific certainty shall not be used as a reason for postponing cost-effective measures to prevent environmental degradation.

Importantly, oil companies and others have been brought into the legal ambit. The opinion underscores the evolving regulatory landscape concerning climate responsibility, and points to heightened scrutiny and regulatory enforcement concerning greenhouse gas emissions and environmental preservation.

The further significance of the ITLOS Advisory Opinion is that it will be cited in national, regional and international courts on all matters related to climate change. Immediately, it will be taken into account by the Inter-American Court on Human rights, which is currently considering a case, brought in January 2023 by Chile and Colombia, for an Advisory Opinion to address the climate emergency within the framework of international human rights law. Similarly, the International Court of Justice (ICJ) is now considering a request from the UN General Assembly, prompted by Vanuatu, to provide an Opinion on the obligations of states regarding Climate Change. The ICJ will undoubtedly consider the ITLOS Opinion before rendering its own Opinion by January 2025.

So, the ITLOS opinion has put a juggernaut in motion. The matter of the impact of Climate Change is no longer a matter for negotiation between powerful nations and weak states at COP – the stage is enlarged from a gladiatorial arena to include the precincts of law. The playing field is less uneven, and small island states are now imbued with a sense of hope and optimism.

But both industrial nations and their companies, which profit worldwide, will fight back to preserve their advantages. Having seen that the law is on their side, all of the small states, including those that did not join the COSIS effort, should bind together to secure their own advantage, which the ITLOS Opinion has provided.