Background
In May 2024, the International Tribunal for the Law of the Sea (ITLOS) issued a landmark advisory opinion on climate change, responding to a request from the Commission of Small Island States on Climate Change and International Law (COSIS). This advisory opinion sought to clarify the obligations of states under the United Nations Convention on the Law of the Sea (UNCLOS) in the context of climate change and ocean acidification, emphasizing the urgent threats faced by small island states.
Key Findings of the Advisory Opinion
Climate Change as Marine Pollution:
ITLOS concluded that anthropogenic greenhouse gas (GHG) emissions fall under the definition of “pollution of the marine environment” as outlined in Article 1(1)(4) of UNCLOS. This categorization obligates states to take all necessary measures to prevent, reduce, and control such pollution. The Tribunal stressed that climate change impacts, including rising temperatures and ocean acidification, significantly threaten marine ecosystems.
State Obligations Under UNCLOS:
The advisory opinion highlighted several key obligations for states under UNCLOS:
- Due Diligence: States are required to exercise stringent due diligence to regulate activities that emit GHGs, including implementing legislation, administrative procedures, and enforcement mechanisms. This duty includes both public and private sector activities.
- Environmental Impact Assessments (EIAs): States must conduct comprehensive EIAs for any planned activities that may harm the marine environment, considering both specific and cumulative impacts of GHG emissions.
- Precautionary Approach: States should adopt a precautionary approach in their efforts to prevent, reduce, and control marine pollution from GHG emissions, ensuring actions are taken even in the face of scientific uncertainty.
Rejection of Lex Specialis Argument:
The Tribunal dismissed arguments that compliance with the Paris Agreement alone suffices to meet UNCLOS obligations. ITLOS clarified that the Paris Agreement is not lex specialis to UNCLOS, meaning it does not override or replace the broader obligations under UNCLOS regarding marine pollution.
Support for Developing States:
Developed states have legally binding obligations to support developing states, including small island states, in building capacity, transferring technology, and providing financial resources to address climate change impacts on the marine environment.
Implications and Next Steps:
The advisory opinion from ITLOS serves as a critical legal precedent, emphasizing the stringent obligations of states to combat marine pollution caused by GHG emissions under UNCLOS. This opinion reinforces the need for robust national and international measures to mitigate climate change impacts on marine ecosystems.
Implications of the opinion:
Based on the ITLOS Advisory Opinion, states are expected to:
- Enhance legislative and regulatory frameworks to control GHG emissions.
- Implement effective EIAs for activities potentially impacting the marine environment.
- Strengthen international cooperation, particularly in supporting vulnerable states through capacity building and technology transfer.
Conclusion
This advisory opinion is anticipated to influence global climate policies and actions, driving greater alignment of national efforts with international legal standards to protect the marine environment from the adverse effects of climate change.
