World "Ocean Court" Issues Groundbreaking Decision Affirming States Must Slash GHG Emissions To Protect Marine Environment

Countries must step up climate action and take all necessary measures to reduce greenhouse gas emissions in line with the best available science in order to help protect and preserve the marine environment, an international tribunal has determined.

The highly anticipated advisory opinion from the International Tribunal for the Law of the Sea (ITLOS), delivered on May 21 in Hamburg, Germany, marks the first time that an international court has weighed in on the question of states’ responsibilities to combat climate change as a matter of ocean protection. It is the first of three advisory opinions to be issued from international tribunals that are expected to clarify states’ legal obligations to address climate change under international law, which observers say will help inform global climate negotiations under the UNFCCC regime and can provide persuasive authority in climate accountability court proceedings.

Developed in response to a request from a coalition of nine small island states, the advisory opinion from ITLOS affirms that climate action is a legal duty; under the UN Convention on the Law of the Sea (UNCLOS) – a legally binding ocean treaty established in 1982 – countries have specific obligations to mitigate ocean pollution and adverse effects on the marine environment from anthropogenic greenhouse gas emissions. Such emissions, including from sources on land or through the atmosphere or at sea, constitute pollution of the marine environment, the tribunal found. This determination gives rise to the obligations to reduce marine pollution stemming from climate change, such as ocean acidification, and for states to work both individually and cooperatively to implement their obligations.

Legal experts responded to the advisory opinion highlighting its significance and historic nature.

Lea Main-Klingst, a lawyer with UK-based environmental law charity ClientEarth, said that the small island states spearheading the request for the opinion “have succeeded in a world first.” The tribunal’s decision, she said, “has made it clear that states worldwide must reduce their emissions to protect our ocean.”

“The ITLOS advisory opinion marks a significant step forward in international environmental law and the protection of our oceans,” Louise Fournier, legal counsel for climate justice and liability at Greenpeace International, said in a statement. “It sets a clear legal precedent for addressing climate change through existing international frameworks and reinforces States’ responsibilities to act on climate change.”

Advisory opinions are not themselves legally binding, but they are considered highly influential and can provide states and courts with important guidance, experts say. The opinion in this case clarifies obligations under the UNCLOS treaty – considered the “Constitution of the Ocean” – which is binding for the 169 countries that have ratified it (the United States has not ratified it, making it not formally party to the Convention). Countries that fail to meet their obligations to effectively address climate change under the Law of the Sea Convention, the tribunal suggests, could be held liable.

These obligations, detailed in the tribunal’s unanimous opinion, include:

• Taking “all necessary measures” to prevent, control and reduce marine pollution from anthropogenic GHG emissions, taking into account the best available science and particularly the goal of limiting global temperature rise to no more than 1.5°C, and taking measures to ensure that emissions under states’ control do not damage other states’ environments;
• Adopting laws and regulations to mitigate emissions and enforcing them, and cooperating “continuously, meaningfully and in good faith” in endeavors to prevent, reduce and control pollution of the marine environment from anthropogenic GHG emissions;
• Providing assistance, such as capacity-building and funding, to vulnerable developing states to aid their efforts in climate mitigation;
• Monitoring, reporting and conducting environmental impact assessments for activities anticipated to adversely affect the marine environment;
• Protecting and preserving the marine environment from climate change impacts and ocean acidification, including protecting marine environment habitat and other threatened forms of marine life from harmful climate impacts and conserving living marine resources, which requires a precautionary and ecosystem-based approach.
  Additionally, the tribunal found that states’ mere participation in the UN climate negotiations and adoption of the Paris Climate Agreement may not suffice to satisfy these obligations, implying additional actions are needed. That includes regulating business activities that significantly contribute to GHG emissions, suggesting that the tribunal’s decision may have far-reaching implications for corporate climate polluters and their enablers.
  
  “Because business must follow where governments lead, companies and financial institutions are going to feel a knock-on effect from this development, too – no matter where they operate,” Main-Klingst said.
  
  High-ranking officials from the small island states leading this historic international legal initiative said the advisory opinion could be instrumental to efforts to hold big climate polluters accountable.
  
  “This is a historic moment for small island developing nations in their quest for climate justice; an important step in holding major polluters accountable, for the sake of all humankind,” Tuvalu High Commissioner to Fiji H.E. Eselealofa Apinelu said in a press release.
  
  “Small Island States are fighting for their survival. Some will become uninhabitable in the near future because of the failure to mitigate greenhouse gas emissions. We demand that the major polluters respect international law, and stop the catastrophic harm against us before it’s too late,” Gaston Browne, prime minister of Antigua and Barbuda, said.
  
  Tuvalu and Antigua and Barbuda were co-leads on this ITLOS advisory opinion initiative, submitted in December 2022 by the Commission of Small Island States on Climate Change and International Law (COSIS), a group formed in 2021 that includes Tuvalu, Antigua and Barbuda, Vanuatu, Palau, Saint Vincent and the Grenadines, Saint Kitts and St Nevis, Saint Lucia, Niue, and the Bahamas. These and other low-lying small island states are especially vulnerable to climate impacts like sea level rise, and their very existence in many ways is deeply intertwined with the sea. The advisory opinion comes at a time when atmospheric GHG concentrations have reached record levels, ocean temperatures have been off the charts, and another massive coral reef bleaching event is devastating marine ecosystems. Oceans are the world’s largest carbon sink, absorbing much of the thermal energy from heat-trapping greenhouse gas emissions, resulting in deleterious marine impacts.
  
  The ITLOS advisory opinion is the first of three highly-anticipated advisory opinions on climate change from international tribunals; advisory opinions from the Inter-American Court of Human Rights and the International Court of Justice (ICJ) are forthcoming.
  
  “The momentum from today is only set to grow,” said Main-Klingst, “as 2024 is a year of serious legal reckoning on climate change in international courts.”