Legal Memorandum Advisory Opinion on Climate Change Delivered by the International Tribunal for the Law of the Sea: Relevance for the International Court of Justice Climate Advisory Proceedings

The memorandum examines the ITLOS advisory opinion, which establishes that anthropogenic greenhouse gas (GHG) emissions constitute marine pollution under UNCLOS. It highlights the 'stringent' due diligence required of States to protect the marine environment, the role of the best available science (specifically IPCC reports), and the principle that the Paris Agreement does not supersede UNCLOS obligations. The document also discusses the necessity of environmental impact assessments that account for cumulative and socio-economic impacts, and cautions against marine geoengineering that might transform pollution types.

• The ITLOS Tribunal concluded that anthropogenic greenhouse gas (GHG) emissions into the atmosphere meet the three cumulative criteria of UNCLOS Article 1(1) (4) and therefore constitute "pollution of the marine environment".
• Under UNCLOS Article 192, States have a legal obligation to protect and preserve the marine environment from climate change and ocean acidification, which requires a "stringent" standard of due diligence given the risk of irreversible harm.
• The ITLOS AO establishes that the Paris Agreement and UNCLOS are separate agreements with distinct obligations; consequently, complying with the Paris Agreement alone is insufficient to fulfill a State's obligations under UNCLOS Article 194(1) to prevent, reduce, and control marine pollution.
• The standard of due diligence for States is determined objectively and must be informed by the best available science, specifically the works of the Intergovernmental Panel on Climate Change (IPCC).
• The Tribunal determined that environmental impact assessments (EIAs) for planned activities that may cause substantial marine pollution through GHG emissions must include cumulative impacts and may include socio-economic impacts.
• Regarding equity, the ITLOS AO asserts that while all States must make mitigation efforts, those with greater capabilities must do more, though this cannot be used as an excuse to postpone the implementation of necessary measures.
• The Tribunal cautioned that marine geoengineering could violate UNCLOS Article 195 if it results in transforming one type of pollution into another, or Article 196 regarding the use of technologies under a State's jurisdiction.

APA

Center for International Environmental Law (2024). Legal Memorandum Advisory Opinion on Climate Change Delivered by the International Tribunal for the Law of the Sea: Relevance for the International Court of Justice Climate Advisory Proceedings. https://www.ciel.org/wp-content/uploads/2024/07/Final_-Legal-Memorandum_-Relevance-of-ITLOS-climate-AO-for-the-ICJ-AO_CIEL_July-2024.pdf

Chicago

Center for International Environmental Law. Legal Memorandum Advisory Opinion on Climate Change Delivered by the International Tribunal for the Law of the Sea: Relevance for the International Court of Justice Climate Advisory Proceedings. 2024. https://www.ciel.org/wp-content/uploads/2024/07/Final_-Legal-Memorandum_-Relevance-of-ITLOS-climate-AO-for-the-ICJ-AO_CIEL_July-2024.pdf.

Wikipedia

{{cite report |author=Center for International Environmental Law |title=Legal Memorandum Advisory Opinion on Climate Change Delivered by the International Tribunal for the Law of the Sea: Relevance for the International Court of Justice Climate Advisory Proceedings |date=July 2024 |url=https://www.ciel.org/wp-content/uploads/2024/07/Final_-Legal-Memorandum_-Relevance-of-ITLOS-climate-AO-for-the-ICJ-AO_CIEL_July-2024.pdf |access-date=17 August 2026 |via=Climate Insights Directory}}

BibTeX

@techreport{centerforinternationalenvironmentallaw2024legal, author = {{Center for International Environmental Law}}, title = {{Legal Memorandum Advisory Opinion on Climate Change Delivered by the International Tribunal for the Law of the Sea: Relevance for the International Court of Justice Climate Advisory Proceedings}}, institution = {Center for International Environmental Law}, year = {2024}, month = jul, url = {https://www.ciel.org/wp-content/uploads/2024/07/Final_-Legal-Memorandum_-Relevance-of-ITLOS-climate-AO-for-the-ICJ-AO_CIEL_July-2024.pdf}, urldate = {2026-08-17}, note = {Indexed by Climate Insights Directory} }