By Ayyoub (Hazhar) Jamali, postdoctoral researcher at the University of Zurich
Summary:
On 12 December 2022, the Co-Chairs of the Commission of Small Island States on Climate Change and International Law formally requested an advisory opinion from the International Tribunal for the Law of the Sea (ITLOS). This request sought to clarify the obligations of State Parties under the United Nations Convention on the Law of the Sea (UNCLOS) in relation to addressing the effects of climate change on the marine environment. The request underscored the significant challenges that small island states face due to climate change, particularly concerning ocean warming, sea level rise, and ocean acidification caused by anthropogenic greenhouse gas (GHG) emissions.
The Commission posed two key questions to ITLOS:
- What are the specific obligations of State Parties under UNCLOS, particularly Part XII, to prevent, reduce, and control pollution of the marine environment caused by climate change? This includes addressing ocean warming, sea level rise, and ocean acidification resulting from human-generated GHG emissions.
- What responsibilities do State Parties have under UNCLOS to protect and preserve the marine environment from the impacts of climate change?
The Advisory Opinion:
Question 1: Obligations to Prevent, Reduce, and Control Pollution
The Tribunal first addressed whether anthropogenic GHG emissions qualify as ‘pollution of the marine environment’ under Article 1, paragraph 1, subparagraph 4, of UNCLOS. In doing so, it analysed the three cumulative criteria outlined in the Convention’s definition. The Convention defines pollution as the human introduction of substances or energy into the marine environment that results or is likely to result in harmful effects. The Tribunal finds that GHGs, as gases, meet the first criterion of being substances. Furthermore, it concludes that anthropogenic GHG emissions are produced by humans and can directly or indirectly introduce substances and energy, such as heat, into the marine environment, satisfying the second criterion. The third criterion is that the introduction of these substances or energy must result or be likely to result in deleterious effects. The Tribunal finds that anthropogenic GHG emissions lead to ocean acidification and global warming, which harm marine life and ecosystems, thus satisfying the third criterion. Therefore, the Tribunal recognises anthropogenic GHG emissions as pollution of the marine environment based on the cumulative fulfilment of all three criteria (paras. 159-179).
The Tribunal held that under Article 194, paragraph 1, State Parties have specific obligations to take all necessary measures to prevent, reduce, and control marine pollution from GHG emissions. These measures must be guided by the best available science and international standards, including the United Nations Framework Convention on Climate Change (UNFCCC) and the Paris Agreement, which aim to limit global temperature increase to 1.5°C above pre-industrial levels. The scope and content of these measures may vary according to States’ capabilities and available resources. Measures should include significant reductions in GHG emissions (para. 258).
Additionally, under Article 194, paragraph 2, States are required to ensure that GHG emissions within their jurisdiction do not harm other States or spread beyond their national borders. This transboundary obligation is particularly stringent due to the high risk of serious and irreversible harm from such emissions. The Tribunal emphasised that States must adopt laws and regulations to control pollution from land-based sources, vessels, and atmospheric sources, per Articles 207, 211, 212, 213, and 222 of UNCLOS. These regulations should align with internationally agreed rules and standards (para. 260).
The Tribunal also argued that the Paris Agreement is not considered a lex specialis to the UNCLOS. It emphasised that while both the UNFCCC and the Paris Agreement are primary legal instruments addressing climate change, they do not modify or limit the obligations under UNCLOS. Specifically, Article 194, paragraph 1, of UNCLOS imposes a distinct and stringent obligation on States to take all necessary measures to prevent, reduce, and control marine pollution from GHG emissions. Compliance with the Paris Agreement does not suffice to meet this obligation under UNCLOS. Instead, the Paris Agreement complements UNCLOS by providing relevant international rules and standards, but it does not supersede or replace the specific obligations set forth in UNCLOS. The Tribunal concluded that the principle of lex specialis derogat legi generali is not applicable in this context, as the Paris Agreement and UNCLOS serve different legal functions and address separate aspects of environmental protection (paras. 219-224).
The Tribunal also underscored the importance of international cooperation under Articles 197, 200, and 201. It held that States are obligated to work together through competent international organisations to prevent marine pollution from GHG emissions. This cooperation includes formulating and elaborating rules, conducting scientific research, and sharing information on the risks and remedies of marine pollution from GHG emissions. Furthermore, under Articles 202 and 203, States must assist developing and vulnerable States through capacity-building, technology transfer, and financial aid (paras. 321-322, 367).
Question 2: Responsibilities to Protect and Preserve the Marine Environment
In response to the second question, the Tribunal indicated that Article 192 of UNCLOS imposes a broad obligation on States to protect and preserve the marine environment from any harm or threat, including those posed by climate change and ocean acidification. This obligation includes taking preventive measures to anticipate risks and mitigate their impacts. When the marine environment has been degraded, States may be required to undertake restoration efforts (paras. 384-386).
The Tribunal further explained that under Article 194, paragraph 5, States have a specific obligation to protect rare or fragile ecosystems and the habitats of threatened or endangered species from climate change impacts. This protection requires proactive and precautionary measures (para. 406).
Additionally, Articles 61 and 119 mandate States to conserve living marine resources threatened by climate change, using the best available science and considering environmental and economic factors. This includes applying the precautionary approach and an ecosystem-based approach to management (paras. 414, 418).
The Tribunal noted that Articles 63 and 64 obligate States to consult and cooperate with each other to coordinate effective conservation measures for shared stocks, considering the impacts of climate change and ocean acidification. Article 118 further requires States to cooperate in conserving living marine resources in the high seas (para. 423)
Lastly, the Tribunal emphasised that under Article 196, States are required to prevent, reduce, and control pollution from non-indigenous species introduced due to climate change, which may cause significant marine environmental changes. This obligation also necessitates the application of the precautionary approach to mitigate the adverse effects of such introductions (para. 436).
Conclusion:
The ITLOS’s advisory opinion provided a detailed interpretation of the obligations of State Parties under UNCLOS in the context of climate change. It confirmed that anthropogenic GHG emissions constitute pollution of the marine environment and that States have a duty to take all necessary measures to prevent, reduce, and control such pollution, guided by the best available science and international standards, including the UNFCCC and the Paris Agreement. It emphasised that the Paris Agreement is not considered a lex specialis to the UNCLOS. The Tribunal emphasised the importance of international cooperation, stringent regulatory measures, and proactive strategies to mitigate the adverse impacts of climate change on the marine environment. States are also required to assist developing and vulnerable nations in their efforts to combat these impacts. Additionally, the Tribunal highlighted the broad obligation to protect and preserve the marine environment from climate change, including the protection of rare ecosystems and the conservation of living marine resources.