Climate Action

Key Takeaways

• Anthropogenic greenhouse gas emissions amount to pollution of the marine environment for the purposes of the United Nations Convention on the Law of the Sea (UNCLOS).
• Compliance with the United Nations Framework Convention on Climate Change (UNFCCC) and the Paris Agreement is not sufficient to discharge a State’s obligations to protect and preserve the marine environment from the adverse effects of climate change.
• States have a ‘stringent’ duty of due diligence under which they have to put in place legislation, administrative procedures, and enforcement mechanisms to regulate activities emitting greenhouse gases, including from the private sector.

Introduction

On 21 May 2024, the International Tribunal for the Law of the Sea (ITLOS) handed down its advisory opinion in Request for an Advisory Opinion submitted by the Commission of Small Island States on Climate Change and International Law (Request for Advisory Opinion submitted to the Tribunal) (ITLOS Advisory Opinion).

In this two-part series, we will unpack the ITLOS Advisory Opinion. In Part I, we outline the arguments States advanced in the written and oral proceedings of the ITLOS Advisory Opinion, and the Tribunal’s key findings. In Part II, we discuss the potential implications for governments and the private sector arising from the ITLOS Advisory Opinion, and where to next.

Our previous article, Climate Change in the Spotlight: The Advisory Opinion Proceedings of the International Courts, also provides a high-level overview of the ITLOS and ICJ advisory opinion proceedings and considers the potential implications of each at both international and domestic levels.

Background to the Advisory Opinion

On 12 December 2022, the Tribunal received a request from the Commission of Small Island States on Climate Change and International Law, comprising of Antigua and Barbuda, Niue, Palau, Saint Lucia, Tuvalu, and Vanuatu (COSIS) to render an advisory opinion. Per the COSIS Agreement, COSIS’s mandate is “to promote and contribute to the definition, implementation, and progressive development of rules and principles of international law concerning climate change”.

COSIS referred the following questions to ITLOS for an advisory opinion:

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

1. 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?
2. to protect and preserve the marine environment in relation to climate change impacts, including ocean warming and sea level rise, and ocean acidification?

From 11 to 25 September 2023, the 21 Members of the Tribunal heard oral arguments from 35 States Parties to UNCLOS and three intergovernmental organisations. This was in addition to the written submissions received from 34 States Parties and nine intergovernmental organisations. A further 10 statements from various international bodies were filed.

While 43 participants may not seem a large grouping, a total of 45 States and four international organisations made written statements in the 2004 International Court of Justice (ICJ) advisory opinion on the Legal Consequences of the Construction of a Wall in the Occupied Palestinian Territory – being the former advisory opinion proceeding with the highest engagement. It is clear from the turn out at ITLOS that climate change sits high on the agenda of the international community.

This has only recently been dwarfed by the first written round of the ICJ’s climate change advisory opinion where 79 written statements were received from 83 States,¹ including from seven Least Developed Countries (LDCs), 18 Small Island Developing States (SIDS), and four States that are both LDCs and SIDS. The ICJ also received statements from 12 intergovernmental organisations, meaning a total of 91 written statements were received.

What were the arguments States made?

As a threshold issue, the overwhelming majority of States argued that anthropogenic greenhouse gas (GHGs) emissions fall within the definition of ‘pollution of the marine environment’ under article 1(1)(4) of UNCLOS. This is important as an inclusive definition empowers the Tribunal to consider the impacts of such emissions on the marine environment.

In terms of substantive obligations, two UNCLOS provisions formed the foundation of almost every States’ submission, being articles 192 and 194 of UNCLOS. Article 192 imposes a general obligation on States to protect and preserve the marine environment. Article 194 requires States to take all measures necessary to prevent, reduce, and control pollution of the marine environment from any source, using the best practicable means at their disposal. Several States also made submissions on whether the ‘duty to cooperate’ forms part of States Parties’ obligations under UNCLOS, and the extent of the operation of the principle ‘common but differentiated responsibilities’ (being a shared responsibility to respond to climate change where the nature of obligations imposed are influenced by a State’s respective capabilities and level of development).

While all States considered the role of articles 192 and 194 in their submissions, three groups of arguments formed:

1. COSIS’s position – States’ obligations in UNCLOS should be read to include the 1.5°C temperature goal agreed to in the Paris Agreement

COSIS took a firm position on the content of States’ obligations regarding emissions reduction and protection of the marine environment. COSIS argued that articles 192 and 194 of UNCLOS impose clear and specific obligations on States to take action in response to climate change, including an obligation to take all necessary measures aimed at reducing GHG emissions from all sources to limit the average global temperature rise to 1.5°C. COSIS’s argument relied heavily on the climate science findings in the Intergovernmental Panel on Climate Change (IPCC) reports, including emphasising the need to have States’ specific legal obligations under UNCLOS to be benchmarked against the 1.5 °C temperature goal in article 2 of the Paris Agreement.

COSIS submitted that States may be required to go further than commitments made in the Paris Agreement (and other climate change treaties) in order to comply with their obligations under UNCLOS.

2. Middle position – States’ obligations under UNCLOS should be read in light of / informed by commitments made under climate change treaties

This category of States recognised that where there are multiple obligations that relate to a single issue, these obligations should be, to the extent possible, interpreted in a way to give rise to a single set of compatible obligations. On that basis, States’ obligations under UNCLOS should be read in light of commitments made in later treaties such as the UNFCCC and the Paris Agreement. States in this category stopped short of suggesting that the obligations in the UNFCCC and Paris Agreement could be imported to circumscribe States’ obligations under UNCLOS. Some States further recognised that environmental obligations under UNCLOS may go beyond those contained in the UNFCCC and the Paris Agreement.

3. Hard-line against COSIS position – States’ obligations under UNCLOS and the climate change treaties are separate

A number of States adopted a position in direct contrast with COSIS. These States argued the climate change treaties (eg, the UNFCCC and the Paris Agreement) constitute a specialised regime to regulate GHG emissions. On that basis, compliance with those agreements should mean compliance with States’ obligations under UNCLOS to protect and preserve the marine environment from the effects of anthropogenic GHG emissions. These States were clear that non-binding commitments made under the climate change treaties, namely commitments to the goal of limiting global temperature increase to well below 2°C, should not be imported into UNCLOS as specific legal obligations on States.

The Tribunal’s findings

The ITLOS Advisory Opinion is a positive step for greater climate action. In assessing States’ obligations under UNCLOS, the Tribunal concluded that States have a ‘stringent’ duty of due diligence, under which they have to put in place legislation, administrative procedures, and enforcement mechanisms to regulate activities emitting GHGs – including from the private sector.

The Tribunal also dismissed several key arguments that some developed States were advancing including that compliance with the Paris Agreement was sufficient to discharge a States’ obligations under UNCLOS in respect of GHG emissions. The Tribunal also affirmed that developed States have legally binding obligations to support developing States in terms of capacity building, scientific expertise, technology transfer, and financing.

However, when the Tribunal’s findings are read more closely, the Tribunal’s conclusions are cautious and in some sections are simply a recitation of the provisions of UNCLOS. While the operative clause of the advisory opinion was unanimous, several Tribunal Members issued separate declarations which highlighted key points that the Tribunal may not have fulsomely addressed. This section provides a high-level overview of the Tribunal’s findings on the key issues.

ACCEPTING THE SCIENCE BEHIND CLIMATE CHANGE

The Tribunal acknowledged that “climate change is central to the Request and the questions contained therein necessarily have scientific aspects” and that the participants in the proceedings had “submitted or referred to abundant materials on scientific issues” ([46]). Most of the participants in the proceedings referred to reports of the IPCC, recognising them as authoritative assessments of the scientific knowledge on climate change, and that none of the participants challenged the authoritative value of these reports ([51]). The Tribunal relied heavily on the IPCC’s findings in relation to climate science, suggesting it endorsed the relevance and evidential basis of the IPCC’s 2023 Synthesis Report.

ANTHROPOGENIC GHGs FALL WITHIN THE DEFINITION OF POLLUTION OF THE MARINE ENVIRONMENT

The Tribunal concluded that anthropogenic GHGs constitute ‘pollution of the marine environment’ as defined article 1(1)(4) of UNCLOS ([161]). An overwhelming majority of States accepted this position in both the written and oral stages of the proceedings.

REJECTION OF THE CLIMATE CHANGE TREATIES AS LEX SPECIALIS (SPECIALISED REGIME) TO UNCLOS

The Tribunal considered that UNCLOS, the COSIS Agreement, and other relevant rules of international law not incompatible with UNCLOS are the applicable law in the proceedings ([127]). The Tribunal also recognised that the UNFCCC and the Paris Agreement were the “primary legal instruments in addressing the global problem of climate change, [and] are relevant in interpreting and applying the Convention with respect to marine pollution from anthropogenic GHG emissions” ([222]).

However, the Tribunal rejected the use of the lex specialis rule stating that the “Paris Agreement is not lex specialis to the Convention and thus, in the present context, lex specialis derogat legi generali has no place in the interpretation of the Convention” ([224]).

OBLIGATIONS UNDER ARTICLE 194 OF UNCLOS

Article 194 of UNCLOS focuses on States’ obligations to take measures to prevent, reduce, and control pollution of the marine environment. The Tribunal found that the measures to be taken should be determined objectively, taking into account, inter alia, the best available science and relevant international rules and standards contained in climate change treaties such as the UNFCCC and the Paris Agreement, in particular the global temperature goal of limiting the temperature increase to 1.5°C above pre-industrial levels and the timeline for emission pathways to achieve that goal ([222]). The Tribunal made clear that compliance with the UNFCCC and the Paris Agreement did not discharge a State’s obligation under article 194(1) ([220]).

The Tribunal also found that States’ obligations under article 194 were one of due diligence and the standard for due diligence is stringent given the high risks of serious and irreversible harm to the marine environment. The obligation of due diligence may vary according to States’ capabilities and available resources ([226]-[229]). It is therefore the conduct of a State, not the result which would be entailed by the conduct, that will determine whether the State has complied with its obligation under article 194(1) of UNCLOS ([233]).

However, it is important to note that in assessing the standard of due diligence required, the Tribunal concluded that the “the standard of due diligence States must exercise in relation to marine pollution from anthropogenic GHG emissions needs to be stringent…. implementing the obligation of due diligence requires even the latter State [States with fewer means] to do whatever it can in accordance with its capabilities and available resources to prevent, reduce and control marine pollution from anthropogenic GHG emissions” ([241]). States must apply the precautionary approach in their exercise of due diligence to prevent, reduce, and control marine pollution from anthropogenic GHG emissions ([242]).

Related to the concept of due diligence is the carrying out an environmental impact assessments from any planned activity, whether carried out by the public or private sector, that may cause harm to the marine environment. The Tribunal considered how cumulative impacts should be assessed noting:

“Concerning the content of an environmental impact assessment, the Tribunal considers that the broad wording of article 206 of the Convention does not preclude such assessment from embracing not only the specific effects of the planned activities concerned but also the cumulative impacts of these and other activities on the environment. In the context of pollution of the marine environment from anthropogenic GHG emissions, planned activities may not be environmentally significant if taken in isolation, whereas they may produce significant effects if evaluated in interaction with other activities. Moreover, the broad wording of article 206 does not preclude the assessment from including the socio-economic impacts of the activities concerned ([365]) (emphasis added).”

Further, article 194(2) also encompasses an obligation to ensure activities under a State’s jurisdiction or control do not cause damage by pollution to another State (also known as transboundary harm). While the Tribunal concluded that article 194(2) was also an obligation of due diligence it stressed that “[w]ith respect to transboundary pollution affecting the environment of other States, the standard of due diligence can be even more stringent” relative to the standard under article 194(1) ([256]).

Tied to article 194 are articles 207 to 212 of UNCLOS which address States’ obligations to adopt national laws and regulations and establish international rules and standards to prevent, reduce and control marine pollution from six different sources including land-based sources, seabed activities, activities in the Area, dumping, vessels, and pollution from or through the atmosphere.

OBLIGATIONS UNDER ARTICLE 192 OF UNCLOS

Article 192 of UNCLOS imposes a general obligation on States to protect and preserve the marine environment. The Tribunal concluded that where the marine environment has been degraded, this may require restoring marine habitats and ecosystems. This obligation is one of due diligence. The standard of due diligence is stringent, given the high risks of serious and irreversible harm to the marine environment from climate change impacts and ocean acidification ([385], [399]).

Importantly, the Tribunal acknowledge that the term ‘preservation’ may include restoring marine habitats and ecosystems. The term ‘restoration’ is not used in article 192 of UNCLOS but flows from the obligation to preserve the marine environment where the process of reversing degraded ecosystems is necessary in order to regain ecological balance ([386]).

THE DUTY TO COOPERATE & OBLIGATIONS TO PROVIDE TECHNICAL & FINANCIAL ASSISTANCE

Almost all the participants in the proceedings shared the view that countering the effects of anthropogenic GHG emissions on the marine environment necessarily requires international cooperation ([295]).

In relation to marine pollution from anthropogenic GHG emissions, the Tribunal concluded that the duty to cooperate is an integral part of the general obligations under articles 194 and 192 of UNCLOS given that the global effects of these emissions necessarily require States’ collective action ([299]). The Tribunal also stressed that article 197 of UNCLOS “does not oblige States to achieve a normative outcome but to participate meaningfully in the formulation and elaboration of rules, standards and recommended practices and procedures for the protection and preservation of the marine environment” ([307]).

The Tribunal acknowledged that most of the participants in the proceedings were of the view that assistance to developing States is indispensable in combating pollution of the marine environment from anthropogenic GHG emissions ([325]). Articles 202 and 203 of UNCLOS do not refer to the principle of CBDR-RC. However, the obligation of assistance to developing States under these articles has some elements underlying this principle in that States with lesser capabilities need assistance from States that are better placed in order to meet their environmental responsibilities ([326]). The Tribunal concluded articles 202 and 203 of UNCLOS set out specific obligations to assist developing States, in particular vulnerable developing States, in their efforts to address marine pollution from anthropogenic GHG emissions ([339]).

Conclusion

The ITLOS Advisory Opinion is a step forward for greater climate action, allowing UNCLOS to effectively respond to the global phenomenon of climate change. Having unpacked the Tribunal’s key findings, it is important to consider how those findings may be used to advance mitigation of GHG emissions and the climate justice agenda. Part II of this series discusses the potential implications for governments and the private sector arising from the ITLOS Advisory Opinion, and where to next.

DLA Piper’s Experience

DLA Piper was proud to appear before ITLOS in its climate change advisory opinion on a pro bono basis for the Democratic Republic of Timor-Leste in the most significant legal proceeding to date in relation to climate change. Our advocacy in the ITLOS Advisory Opinion resulted in DLA Piper being shortlisted for the Innovation in Responsible Business Award at the FT Innovative Lawyers Asia Pacific 2024 Awards.

The DLA Piper team at ITLOS comprised Stephen Webb (Partner, Brisbane), Gitanjali Bajaj (Partner, Sydney), The Hon. John Middleton AM KC as Senior Counsel (former judge of the Federal Court of Australia and Senior Advisor at DLA Piper, Melbourne), Eran Sthoeger Esq. as Junior Counsel (New York), and Claire Robertson (Solicitor, Brisbane).

DLA Piper is also advising the Governments of Timor-Leste, Tonga, and Solomon Islands in separate submissions in the ICJ climate change advisory opinion.

DLA Piper has a depth of experience in high profile public international law matters of historical significance. DLA Piper is a leader in understanding and advising on legal liability and the legal risks associated with the impacts of climate change. We advise governments and the private sector on climate change related matters, including being the provider of legal services for COP26 – United Nations Framework Convention on Climate Change Conference of the Parties. On commercial projects, the firm has been ranked No. 1 for turnover of closed renewable projects and M+A deals closed for a number of years now. If you would like further information about the advisory opinions proceedings before the international courts, please contact Stephen Webb or Gitanjali Bajaj.