(Brussels, May 21, 2024) – The advisory opinion of the International Tribunal for the Law of the Sea’s (ITLOS) not only reinforces legally binding obligations of states to protect oceans and marine biodiversity, but will also protect livelihoods and the human rights of present and future generations across the globe, Climate Rights International said today. The opinion, announced today in Hamburg, was requested by Antigua and Barbuda, Tuvalu, and the Commission of Small Island States on Climate Change and International Law (COSIS).

“Small island states have contributed the least to climate change, yet they face its most devastating impacts,” said Lotte Leicht, Advocacy Director at Climate Rights International. “The opinion by the Tribunal, which unanimously affirmed the obligation of states to take all necessary measures to reduce pollution from anthropogenic greenhouse gas emissions, is a wake-up call for the largest emitting states, which must now face up to their responsibilities for the climate emergency and take measures to restore degraded marine habitats and ecosystems.”

The ITLOS judges unanimously confirmed that human-caused greenhouse gas (GHG) emissions constitute pollutants of the marine environment under the United Nations Convention on the Law of the Sea (UNCLOS), causing significant harm to the oceans, which are the world’s largest carbon sink. The Tribunal held that all states have an obligation under the Convention to take all necessary measures to prevent, reduce and control marine pollution from such emissions.

In their advisory opinion, ITLOS judges also detailed states’ legal and transboundary obligations to act based on the best available science, follow the precautionary principle, and maintain the global temperature rise to no more than 1.5°C as stipulated in the Paris Agreement. Judges clarified that states must exercise due diligence to prevent and mitigate climate change through their policies, actions, and laws, including by regulating corporate activities. States are liable for their failures to meet these legal obligations.

The ITLOS advisory opinion follows a landmark ruling on April 9 by the European Court of Human Rights holding that parties to the European Convention on Human Rights have a positive obligation to protect individuals from serious adverse effects on their life, health, well-being, and quality of life arising from the harmful effects and risks caused by climate change, and will set the stage for an upcoming advisory opinion by the International Court of Justice requested by the United Nations General Assembly.

“For too long, states have ignored scientific evidence and treated climate change as a secondary soft policy issue,” said Leicht. “Now, courts are making it clear that states are legally required to take comprehensive and urgent climate action to deal with this existential threat. Governments are legally obligated to protect the planet and its people, not only within their own jurisdictions, but globally, from the adverse effects of climate change.”