Energy and climate change: The most significant (marine) climate change decision yet?

Continuing the theme of a number of recent court judgment regarding state and party obligations concerning climate change issues, the International Tribunal for the Law of the Sea (“ITLOS”) has recently delivered its advisory opinion (the “Opinion”) regarding State obligations under the United Nations Convention on the Law of the Sea (“UNCLOS”) in relation to the prevention, reduction and control of pollution of the marine environment that result or are likely to result from climate change.

The Opinion arrived only a few weeks following the ECtHR’s milestone judgment in Verein KlimaSeniorinnen Schweiz and Others v. Switzerland (application no. 53600/20) where the European Court of Human Rights (the “ECtHR”) interpreted States obligations concerning climate change under the European Convention on Human Rights. For CMS commentary on Verein KlimaSeniorinnen Schweiz please click here.

The Opinion was delivered in response to two questions submitted to ITLOS by the Commission of Small Island States on Climate Change and International Law (the “Commission”):

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

The Commission was created under an Agreement for the establishment of the Commission (the “COSIS Agreement”) entered into on 31 October 2021. At the time of the filing, the Commission comprised of six States from the Caribbean and Pacific, including Antigua and Barbuda, Tuvalu, Palau, Niue, Vanuatu and St. Lucia. Subsequently, St. Vincent and the Grenadines, St. Kitts and Nevis, and the Bahamas acceded to the COSIS Agreement.  All members of the Commission are also parties to UNCLOS.

Decision

Jurisdiction  

ITLOS first considered its jurisdiction to respond to the questions put by the Commission and confirmed that it had jurisdiction to provide an advisory opinion on the basis of Article 21 of the ITLOS Statute and Article 138 of its Rules. Article 21 of the ITLOS Statute provides that “The jurisdiction of the Tribunal comprises all disputes and all applications submitted to it in accordance with this Convention and all matters specifically provided for in any other agreement which confers jurisdiction on the Tribunal.” ITLOS found that the COSIS Agreement, which expressly authorised the Commission to request advisory opinions from ITLOS, constituted such an “other agreement” conferring advisory jurisdiction on ITLOS and a request for an opinion was transmitted by a body authorised to do so.

ITLOS’s discretion to refuse to proffer an advisory opinion was also considered. Ultimately, ITLOS elected to use its discretion to give the Opinion taking account of the facts that the questions were ‘clear and specific’, the request was ‘compatible with its judicial functions’ and a vast majority of the participating States party to UNCLOS expressed support for an advisory opinion.

Answers to the substantive questions

Having dealt with preliminary jurisdiction considerations, ITLOS then turned to the questions posed by the Commission:

Question a: whether anthropogenic greenhouse gas emissions into the atmosphere constitute pollution of the marine environment as defined by Article 1, paragraph 1, subparagraph 4, of the Convention, and if so, what are the obligations of State Parties to the Convention under Part XII to prevent, reduce, and control such pollution

ITLOS observed that Article 1(4) of UNCLOS sets out three criteria to determine what constitutes pollution of the maritime environment: ”(1) there must be a substance or energy; (2) this substance or energy must be introduced by humans, directly or indirectly, into the marine environment; and (3) such introduction must result or be likely to result in deleterious effects.”

ITLOS concluded that anthropogenic GHG emissions (i.e. those caused by human activities) meet these three criteria – such emissions alter the physical, chemical and biological properties of the marine environment, result in adverse effects on marine life and human health and also interfere with the legitimate uses of the sea.  ITLOS referred by way of example to the consequences of CO2 dissolving into seawater leading to ocean warming and ocean acidification in support of that conclusion.

ITLOS then considered the proper interpretation of a number of specific UNCLOS provisions relevant to the State Parties’ obligations to prevent, reduce and control marine pollution caused by such emissions:

1. The obligation to ‘protect and preserve the marine environment’ (Article 192): ITLOS interpreted this Article as placing constraints on the State Parties’ sovereign right to exploit natural resources pursuant to Article 193, which is itself qualified by an obligation to do so “in accordance with their duty to protect and preserve the marine environment”. According to ITLOS, those two articles together illustrate the importance that UNCLOS attaches to protection of the marine environment.

2. The obligation to take all necessary measures to prevent, reduce and control pollution of the marine environment “from any source’’ (whether land-based, sea-based or airborne) (Article 194): ITLOS stated that this obligation does not entail the immediate cessation of anthropogenic GHG emissions; it is an obligation of conduct rather than an obligation of result. It requires State Parties to deploy “best efforts” to control marine pollution, in accordance with their respective capabilities.

This means State Parties must exercise “due diligence” in relation to the activities under their jurisdiction and control and their impact on the marine environment, having regard to the global temperature goal under the Paris Agreement of limiting the temperature increase to 1.5°C above pre-industrial levels and the timeline for emission pathways to achieve that goal.

The obligation of “due diligence” requires States to put in place a national system, including legislation, administrative procedures and an enforcement mechanism necessary to regulate the activities in question, and to exercise adequate vigilance to make such a system function efficiently, with a view to achieving the intended objective. Importantly, while “due diligence” is a “variable concept”, in the context of climate change mitigation, ITLOS observed that the standard of due diligence is stringent, given the risk of irreversible harm to the marine environment. Crucially, the steps to be taken must be “as far-reaching and efficacious as possible to prevent or reduce the deleterious effects of climate change and ocean acidification on the marine environment”. Where a State fails to comply with this obligation, international responsibility would be engaged for that State.

Crucially, ITLOS found that the obligation under Article 194 would not be satisfied simply by complying with the obligations and commitments under the Paris Agreement. What constitutes “necessary” measures under Article 194 must be determined objectively, based on the best available science on climate change, which in this context ITLOS considered are the reports issued by the Intergovernmental Panel on Climate Change (“IPCC").  Further, to determine what measures are necessary, States must be guided by the precautionary approach. The lack of full scientific certainty cannot be relied on by States as a justification for not taking all necessary measures.

ITLOS also stated that the duty to take all necessary measures is to be exercised in accordance with States’ respective capabilities and therefore the level of action expected from different States would vary depending on their means, stages of economic development and other specific circumstances.

3. Obligations to support developing States (Articles 202 and 203): The obligation for developed states to provide scientific and technical assistance to developing states with preventing marine pollution from GHG emissions (Article 202) and the obligation to assist particular States vulnerable to climate change by granting them preferential treatment to funding, technical assistance and specialised services from international organisations (Article 203) were both emphasised by ITLOS, which also noted that small island states, such as those who submitted the questions, are disproportionately suffering the devastating effects of such pollution.

4. ITLOS also noted the obligations to:

1. adopt laws and regulations to prevent, reduce and control marine pollution from GHG emissions that originate onshore or atmospherically, taking into account internationally agreed rules and recommended practice (Articles 207 and 212);
2. adopt laws and regulations to prevent such pollution emanating from vessels registered to that state or flying the flag of that state and ensuring compliance of those vessels with international rules (Articles 211 and 217);
3. enforce their laws and regulations and take measures necessary to achieve relevant international rules and standards (Articles 213 and 222);
4. cooperate with one another to prevent, reduce and control marine pollution emanating from GHG emissions (Articles 197, 200 and 201); and
5. monitor and produce reports and environmental assessments on marine pollution from anthropogenic GHG emissions (Articles 204, 205 and 206).

Question b: protecting and preserving the marine environment in relation to climate change impacts

At the outset of its consideration of Question b, ITLOS noted that Question b was “independent, but complimentary to the first” (in the words of the Commission).

Taking a similar approach to that of Question a, ITLOS went on to identify various legal obligations within UNCLOS that require States to protect and preserve the marine environment. Importantly, ITLOS acknowledged that the States’ obligation to protect and preserve the marine environment (Article 192) calls for both anticipatory and restorative action, and encompasses any type of harm or threat to the marine environment, including climate change impacts and ocean acidification.

Comments

It remains to be seen what the true impact of the Opinion will be and whether and how it will be adopted by national courts and other international tribunals. However, we make the following observations:

1. By its Opinion, ITLOS has reminded the 168 States and 1 international organisation that are parties to UNCLOS of their legal obligation to protect ocean against effects of climate change, including by taking measures to reduce GHG emissions. While ITLOS did not consider the legal consequences arising from the breach of States’ obligations under UNCLOS relevant to climate change, it noted that for States failing to comply with their obligations to use all necessary measures to protect the marine environment from the deleterious effect of climate change, their international legal responsibility would be engaged. That appears to pave the way for future international proceedings between States or groups of States based on alleged failure to comply with the relevant UNCLOS provisions and the ensuing consequences. In doing so, ITLOS appears to have established a legal framework for climate change litigation specific to marine pollution.
    
2. ITLOS’s observation that States are constrained in exploiting their natural resources by their obligation to protect the marine environment is significant, as it appears to prioritise environmental protection over sovereignty to exercise economic rights in the context of climate mitigation.
    
3. Crucially, ITLOS was clear that compliance with the Paris Agreement is not sufficient for States to comply with their obligations under Art.194 to take all necessary measures to protect the marine environment. This means that submitting nationally determined contributions (NDCs) as required by the Paris Agreement does not of itself amount to taking “all necessary measures”. ITLOS further stated that the Paris Agreement cannot be considered as lex specialis vis-à-vis UNCLOS when it comes to climate mitigation in the context of the duty to protect the marine environment.  Therefore, it is not within States’ exclusive prerogative to determine what the “necessary” measures are; if the measures they adopt are not bold enough to pass the objective test of what “all necessary measures” means under UNCLOS, they would have breached their obligations under UNCLOS and their legal responsibility under international law could be engaged.
    
4. ITLOS’s view that the obligation to take “all necessary measures” is to be determined objectively is key, as it adds an extra layer to what the Paris Agreement requires. ITLOS considered that it is not enough for States to submit NDCs that they see fit, rather they must strive to adopt GHG mitigation measures which are the most efficient available to them to achieve the 1.5 degree target based on their respective capabilities.  Considering these findings, States may consider implementing more rigorous legislation relating to regulation of GHG emissions, along with stricter enforcement mechanisms to ensure compliance.
    
5. ITLOS’s ruling that obligations of the relevant State would depend upon its capabilities this may open the door for small developing and least developed States to argue that far bolder action is required from developed States and potentially to seek to invoke their international legal responsibility on that basis.
    
6. The general trend appears to be towards decisions requiring States to go further, faster, in their efforts to address climate change and environmental issues.  It seems likely that these recent high-profile decisions will encourage more litigation by climate change groups seeking to ensure that progress is accelerated.
    
7. More generally, it seems these international courts and tribunals are prepared to set themselves as ‘gate keepers’ to monitor implementation by states of international obligations in relation to climate change issues.  This may encourage further claims by campaigners in international forums. 
    
8. The timing of the Opinion is notable in the context of the similar requests for advisory opinions in relation to climate change obligations are also pending at the International Court of Justice (“ICJ”) and the Inter-American Court of Human Rights. Compared to ITLOS, whose role is to adjudicate on disputes concerning the international law of the sea, the ICJ has competency over the entirety of international law and so its opinion will be of even greater significance. The expectations from the ICJ advisory opinion vary, but now that the ITLOS Opinion has set what seems to be a high bar in terms of States’ obligations to prevent climate change under UNCLOS, there will likely be equally high expectations of the ICJ’s advisory opinion, which is anticipated in early 2025.