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The ITLOS Advisory Opinion on Climate Change: Key Findings and Considerations for Deep Seabed Mining26 June 2024

Introduction

On 21 May 2024, the International Tribunal for the Law of the Sea (“ITLOS”) issued a landmark Advisory Opinion confirming that the parties to the United Nations Convention on the Law of the Sea (“UNCLOS”) are obliged to take measures to combat marine pollution caused by climate change.

"It is also likely to play an influential role in the burgeoning range of climate change legal actions occurring in domestic courts and internationally."

While not legally binding, the Advisory Opinion clarifies several important aspects of UNCLOS’ environmental obligations and its interaction with broader international environmental law. It is also likely to play an influential role in the burgeoning range of climate change legal actions occurring in domestic courts and internationally. The Advisory Opinion also has relevance for the International Seabed Authority’s (the “ISA” or Authority”) ongoing work to settle regulations for the next phase of deep seabed mining activities.

The Request

The Advisory Opinion was requested by the Commission of Small Island States on Climate Change and International Law (“COSIS”), an international organisation established under an international agreement in 2021 to “promote and contribute to the definition, implementation, and progressive development of rules and principles of international law concerning climate change, including, but not limited to, the obligations of States relating to the protection and preservation of the marine environment and their responsibility for injuries arising from internationally wrongful acts in respect of the breach of such obligations”.

In December 2022, COSIS requested ITLOS to provide an Advisory Opinion on two questions:

What are the specific obligations of State Parties to the United Nations Convention on the Law of the Sea (‘UNCLOS’), including under Part XII:

(a)  to prevent, reduce and control pollution of the marine environment in relation to the deleterious effects that result or are likely to result from climate change, including through ocean warming and sea level rise, and ocean acidification, which are caused by anthropogenic greenhouse gas emissions into the atmosphere?

(b)  to protect and preserve the marine environment in relation to climate change impacts, including ocean warming and sea level rise, and ocean acidification?

Subsequent to COSIS’s request to ITLOS, advisory opinions on climate change have also been sought from the Inter-American Court of Human Rights (“IACtHR”) and the International Court of Justice (“ICJ”). These proceedings have also been accompanied by a multitude of cases brought against governments and companies in domestic legal systems.

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"Anthropogenic GHG emissions are 'pollution of the marine environment' for the purposes of UNCLOS."

The key findings

In an extensive opinion, the Tribunal closely examined Part XII of UNCLOS (titled “Protection and Preservation of the Marine Environment”) and clarified and confirmed its application in relation to greenhouse gases (“GHGs”) in the context of climate change.

Its key factual and legal findings included that:

  • anthropogenic GHG emissions are “pollution of the marine environment” for the purposes of UNCLOS, as they meet each of the criteria established in Article 1(1)(4) of UNCLOS. Namely anthropogenic GHG emissions are (a) “a substance or energy”; (b) that is introduced by humans, directly or indirectly, into the marine environment; and (c) will result in or are likely to result in “deleterious effects”. This analysis drew heavily on the “authoritative assessments” of the Intergovernmental Panel on Climate Change which “reflect the scientific consensus”;
  • States Parties are under an obligation to take “all measures…that are necessary to prevent, reduce and control” GHG pollution “from any source” under Article 194(1) of UNCLOS. This includes an obligation to take measures with a view to “eventually preventing such pollution from occurring at all”, although the Tribunal noted that “this obligation does not entail the immediate cessation of marine pollution from anthropogenic GHG emissions”. The Tribunal also found that there is also a separate and potentially more stringent due diligence obligation to prevent transboundary pollution and damage in the form of GHG emissions, under Article 194(2) of UNCLOS;
  • this obligation is an obligation of due diligence not of result. The mere occurrence of GHG pollution would not mean the State was in breach, provided it had done “whatever it can in accordance with its capabilities and available resources” to properly regulate the relevant activities. This could include measures such as instituting legislation, regulations, administrative procedures and enforcement mechanisms. The Tribunal also made clear that meeting the obligations in the Paris Agreement or other international environmental law treaties is not necessarily sufficient to satisfy what is required under UNCLOS;
  • the precise measures that need to be taken “should be determined objectively” but would vary for each State depending on their “scientific, technical, economic and financial capabilities”. While UNCLOS does not explicitly contain the principle of common but differentiated responsibilities and respective capabilities (“CBR-RC”), these flexibilities provide similar allowances for developing States in particular. The Tribunal also emphasised the obligations under UNCLOS to provide scientific and technical assistance and preferential treatment to developing States to assist them “in their efforts to address marine pollution from anthropogenic GHG emissions”; and
  • UNCLOS imposes a number of procedural obligations in relation to GHG emissions, including to monitor the risks and effects of such pollution and conduct and publish environmental impact assessments (“EIAs”) on activities that “may cause substantial pollution to the marine environment or significant and harmful changes thereto through anthropogenic GHG emissions”.

"The Advisory Opinion also entails a range of more specific considerations for governments and companies involved in deep seabed mining activities in areas beyond the limits of national jurisdiction or negotiations under Part XI of UNCLOS."

Considerations and relevance for Part XI and deep seabed mining activities in the Area

In addition to the important findings of the Tribunal in relation to anthropogenic GHG emissions set out above, the Advisory Opinion also entails a range of more specific considerations for governments and companies involved in deep seabed mining activities in areas beyond the limits of national jurisdiction (the “Area”) or negotiations under Part XI of UNCLOS.

First, the Advisory Opinion confirmed that UNCLOS is to be interpreted as a “living instrument” that is informed by consideration of “coordination and harmonization between the Convention and external rules”. While this finding was specifically focused on Part XII of UNCLOS, the Tribunal referred to broader principles of treaty interpretation when finding that UNCLOS and external rules (including treaty and customary law) must be interpreted consistently “to the extent possible”. In the context of Part XI of UNCLOS, this confirms the appropriateness of considering other areas of international law, including International Investment Law when interpreting and applying its provisions (some of which are often general in nature and lack specificity).

Second, the Advisory Opinion made use of the Authority’s existing regulations governing exploration activities in the Area and considered they represented “the practice of the States Parties to the Convention and of the Authority”. This confirms that the contents of the Authority’s regulations will be relevant to understanding and interpreting Part XI itself. Thus, States in particular should be careful to ensure the contents of these regulations would not have improper implications for the application of, or be ultra vires to, Part XI.

Third, the Tribunal offered guidance on the scope of the term “marine environment”, a term used throughout Part XI and the definition of which is under negotiation as part of the drafting of regulations governing exploitation activities in the Area. The Tribunal considered that the “marine environment” combines “spatial and material components”, “encompasses certain spaces beyond the maritime zones” established by UNCLOS, and includes ecosystems and living organisms. These findings provide further indicia to inform the current negotiations of the definition of this term for the regulations governing exploitation activities in the Area.

Fourth, the Tribunal opined on how States are to determine what “measures…are necessary” to prevent, reduce and control pollution of the marine environment under Article 194(1).  In particular, the Tribunal found that this should be objectively determined and that “the science is particularly relevant in this regard” (although not determinative in and of itself). It also found that international rules and standards are a relevant factor. While these findings are not directly applicable to the obligation in Part XI to take “[n]ecessary measures…with respect to activities in the Area to ensure protection for the marine environment from harmful effects” (Article 145), they will likely inform how this language is interpreted and applied and underlines the importance of science to inform relevant decision making by States and international organisations like the ISA acting on their behalf.

"ITLOS’s Advisory Opinion on climate change is a major development in on-going efforts to respond to climate change, in particular legal efforts to force action on the part of governments."

Fifth, the Tribunal considered that States “must apply the precautionary approach” in regard to GHG pollution as part of their obligation to protect the marine environment. This builds on the Seabed Disputes Chamber’s earlier opinion that there was a “trend towards making [the precautionary approach] part of customary international law” and noting that it was “an integral part of the general obligation of due diligence”.

Sixth, the Tribunal’s consideration of UNCLOS’s obligations in regard to EIAs confirms the work being done by the Authority on these assessments in the context of deep seabed mining (including in the negotiation of regulations and preparation of standards and guidelines). The Advisory Opinion sets out that EIAs are not precluded from considering the cumulative impacts of activities on the environment, particularly in the context of GHG emissions. It also confirms that EIAs can include assessment of socio-economic impacts.

Conclusion

ITLOS’s Advisory Opinion on climate change is a major development in on-going efforts to respond to climate change, in particular legal efforts to force action on the part of governments. It clarifies key aspects of UNCLOS and its relationship to broader customary international law principles and confirms that GHG emissions must be treated as a form of marine pollution. The Advisory Opinion also provides guidance on how Part XI of UNCLOS should be interpreted and applied.

States and companies should be alive to the implications of the Advisory Opinion for their own regulatory frameworks and operations, as well as negotiations of regulations governing deep seabed mining. The Advisory Opinion may also be used to inform and bolster other domestic and international litigation efforts against companies and governments in regard to their climate change impacts and obligations.

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