Legal Analysis Request for an Advisory Opinion from the International Tribunal for the Law of the Sea

The document argues that greenhouse gas emissions constitute pollution under UNCLOS, thereby obligating State Parties to reduce emissions in line with the Paris Agreement's temperature goals. It examines the request for an advisory opinion by the Commission of Small Island States (COSIS) to the International Tribunal for the Law of the Sea (ITLOS), asserting that the duty of due diligence must be informed by the best available science to prevent ocean warming, acidification, and sea level rise.

• The Commission of Small Island States on Climate Change and International Law (COSIS), established on 31 October 2021, requested an advisory opinion from ITLOS on 12 December 2022 regarding State obligations to prevent, reduce, and control marine pollution resulting from anthropogenic greenhouse gas emissions.
• Under UNCLOS Article 1(1)(4), 'pollution of the marine environment' is defined broadly to include the introduction of substances or energy that result or are 'likely to result' in deleterious effects, which the briefing argues encompasses global warming and ocean acidification.
• The duty of due diligence under international law is a variable concept that evolves over time and must be updated in light of new scientific knowledge to remain sufficient.
• The briefing asserts that UNCLOS is a dynamic instrument and should be interpreted through 'systemic integration,' meaning its obligations are informed by other international regimes, specifically the UNFCCC and the Paris Agreement.
• Scientific evidence shows that the world's oceans have absorbed approximately 30% of anthropogenic carbon dioxide and 93% of the extra energy from the enhanced greenhouse effect, leading to ocean warming, acidification, and sea level rise.
• Sea level rise is described as irreversible, with projections that levels will rise between 15 to 30 centimetres by 2050, potentially causing habitat contraction and threatening global peace and security through forced relocation and resource conflict.
• The briefing identifies that land-based activities are primary contributors to marine pollution via the atmosphere, citing that GHG emissions from plastics alone are projected to increase to approximately 6.5 GtCO2e by 2050.

APA

Main-Klingst, L., & Marjanac, S. (2023). Legal Analysis Request for an Advisory Opinion from the International Tribunal for the Law of the Sea. ClientEarth. https://www.clientearth.org/media/belnknjc/itlosao_legal-briefing_final3.pdf

Chicago

Main-Klingst, Lea, and Sophie Marjanac. Legal Analysis Request for an Advisory Opinion from the International Tribunal for the Law of the Sea. ClientEarth, 2023. https://www.clientearth.org/media/belnknjc/itlosao_legal-briefing_final3.pdf.

Wikipedia

{{cite report |last1=Main-Klingst |first1=Lea |last2=Marjanac |first2=Sophie |title=Legal Analysis Request for an Advisory Opinion from the International Tribunal for the Law of the Sea |publisher=ClientEarth |date=June 2023 |url=https://www.clientearth.org/media/belnknjc/itlosao_legal-briefing_final3.pdf |access-date=23 October 2026 |via=Climate Insights Directory}}

BibTeX

@techreport{mainklingst2023legal, author = {Main-Klingst, Lea and Marjanac, Sophie}, title = {{Legal Analysis Request for an Advisory Opinion from the International Tribunal for the Law of the Sea}}, institution = {ClientEarth}, year = {2023}, month = jun, url = {https://www.clientearth.org/media/belnknjc/itlosao_legal-briefing_final3.pdf}, urldate = {2026-10-23}, note = {Indexed by Climate Insights Directory} }