International Court Backs Need to Protect Oceans and Island Nations from Climate Impacts

May 21, 2024 | 2:31 pm
International Tribunal for the Law of the Sea in Hamburg, GermanyITLOS.ORG
L. Delta Merner
Lead Scientist, Science Hub for Climate Litigation

In a historic development, a recent opinion by the International Tribunal for the Law of the Sea (ITLOS) recognizes global warming emissions as a marine pollutant. While nonbinding, the unanimous advisory opinion offers important support for small island nations facing climate impacts and raises the bar for other nations to reduce their global warming emissions to protect the world’s oceans.


Back in December, 2022, a group of small island nations, under the Commission of Small Island States on Climate Change and International Law, submitted a request to the tribunal (pictured above in Hamburg, Germany). They sought to clarify the obligations of state parties under the United Nations Convention on the Law of the Sea (UNCLOS), specifically regarding their duties to prevent, reduce, and control pollution of the marine environment in the context of climate change.

This week, the tribunal released its decision, which marks a significant step forward in the fight against climate change, especially for vulnerable small island countries that are disproportionately affected by rising sea levels and ocean acidification.

Five key highlights

Here are five critical features of the opinion that have potentially far-reaching implications for international environmental policy and marine protection. The opinion:

  • Recognizes global warming emissions as marine pollution. The opinion unequivocally found that human-caused global warming  emissions constitute pollution of the marine environment. This aligns marine protection efforts with broader climate change mitigation strategies and reinforces the need for comprehensive policies that address the root causes of ocean degradation.
  • Lays out polluting nations’ obligations. The court mandates that nations take all necessary measures to prevent, reduce, and control marine pollution from global warming emissions. This sets a stringent standard of “due diligence,” acknowledging the high risks of serious and irreversible harm to marine ecosystems. The opinion also clearly explains that this obligation extends beyond national borders, emphasizing the transboundary nature of both marine and climate pollution, and the need for international cooperation.
  • Brings together international climate agreements. The tribunal highlights the importance of harmonizing national policies with international climate agreements, such as the UNFCCC and the Paris Agreement. This directive ensures that efforts to protect the marine environment are consistent with global temperature goals and emission reduction pathways.
  • Supports vulnerable nations. The decision underscores the need for developed nations to assist vulnerable developing countries, particularly small island countries, in addressing marine pollution. This includes capacity building, technology transfer, and preferential treatment in funding and technical assistance.
  • Calls for comprehensive monitoring and reporting. The decision calls for continuous surveillance, monitoring, and environmental impact assessments to track the effects of global warming emissions on the marine environment. It recommends that nations publish these findings, ensuring transparency and accountability in their environmental policies.

The next challenge: implementation

While the advisory opinion by the international court provides an important legal framework for addressing the impacts of climate change on the marine environment, its nonbinding nature presents a challenge for effective implementation. To ensure that this decision can truly protect our oceans and climate, we need to consider larger global systems and opportunities for ensuring compliance.

Moving forward, nations must begin to incorporate the directives from this decision into their own national laws and regulations. This includes adopting stringent measures to reduce global warming emissions, implementing robust monitoring systems, and conducting thorough environmental impact assessments.

The tribunal’s decision lends important weight to the notion that developed nations have a moral and legal obligation to support vulnerable small island countries. This support should include financial aid, technological assistance, and capacity-building initiatives to help these nations adapt to and mitigate the impacts of climate change. As a global community, we have fallen short on this so far and must prioritize equitable global support.

Finally, continuous scientific research is crucial for understanding the pathways, risks, and remedies of marine pollution from global warming emissions. Countries should invest in data collection, scientific research, and fostering a robust exchange of knowledge to develop effective mitigation and adaptation strategies.

While there is no doubt much to be done, this new international advisory opinion is a historic decision that reinforces the interconnectedness of climate change and marine protection. It sets a high standard of due diligence and calls for comprehensive, international efforts to safeguard our oceans. It also sets an important precedent in international law; I am looking forward to seeing how the Interamerican Court of Human Rights and the International Court of Justice will build upon this decision to help ensure meaningful global action to address climate change.

Right now, nations must urgently and committedly implement the directives in this opinion to protect our marine environment and climate for future generations and countries need to work together through international organizations and diplomatic conferences to establish global and regional rules, standards, and best practices. I hope to see these follow-on mandates from this advisory opinion prominently discussed at the U.N. climate change talks in Azerbaijan (COP29) later this year.