The ITLOS Advisory Opinion: A win for the oceans, a win for the fight against climate change
By Jasmine Rowe and Henrieke Bünger
On the 21st of May 2024, climate history was made when the first ground-breaking Advisory Opinion on the specific obligations of States in regard to climate change was issued by the International Tribunal for the Law of the Sea (ITLOS). As such, the judgement provided key interpretations of the role of the United Nations Convention on the Law of the Sea (UNCLOS) in the face of ambitious climate action. The ITLOS Advisory Opinion is the first of a trilogy of advisory opinions being issued by important international courts and tribunals - including the Inter-American Court of Human Rights (IACtHR) and the International Court of Justice (ICJ) - clarifying the respective State obligations under existing legislation towards climate change. While the legal nature of advisory opinions is non-binding, it provides an authoritative interpretation of existing international obligations.
The request for the Advisory Opinion was brought by the Commission of Small Island States on Climate Change and International Law (COSIS), consisting of the States of Antigua and Barbuda, Tuvalu, the Republic of Vanuatu, Palau, St Lucia and Niue. COSIS was called into existence after the seeming failure of COP26, when small and developing island States joined forces in embarking on the endeavour of clarifying international legal obligations towards the protection from climate change. Given their existential threat by sea level rise and global warming, small and developing island States are spearheading the continuing efforts to seek international support and climate justice.
The ITLOS Advisory Opinion is setting the scene for the forthcoming interpretations and is, thus, of crucial importance in setting a benchmark for the other courts. Hence, this blog aims to analyse certain key aspects and their potential influence in regard to the question of applicable law, the scope of States obligations, and the incorporation of climate science in the courtroom. Additionally, points of contention will be highlighted, such as the absence of the important interlinkage between climate change and human rights and the role of non-State actors in the international sphere.
The questions raised by COSIS
ITLOS was asked to interpret the specific obligations of State Parties to UNCLOS arising from Article 192 to protect and preserve the marine environment and their obligation under Article 194 to prevent, reduce, and control marine pollution. The Tribunal was asked to clarify these responsibilities in relation to the potential effects of climate change such as ocean warming, sea level rise, and ocean acidification resulting from human-induced greenhouse gas emissions. Important to note here is the fact that no court had previously recognised anthropogenic GHGs as a form of pollution. This recognition, however, is a precondition for further responsibilities to derive from the interpretation of the existing obligations at issue in this request, thus marking the Advisory Opinion’s groundbreaking nature.
Crucial Interpretations in the ITLOS Advisory Opinion
Definition of ‘pollution’
In light of the foregoing, a crucial outcome of the Opinion relates to the definition of ‘pollution’ of the marine environment, which States are under an obligation to prevent, reduce and control in line with Article 194 of UNCLOS. ITLOS concluded that anthropogenic GHG emissions constitute a form of pollution within the meaning of Article 1(1)(4) of UNCLOS, which establishes the inextricable link between human-caused emissions and the imminent impact that such have on the marine environment (paras. 178-179). Thus, the interpretation of the respective obligations stemming from UNCLOS, henceforth, inherently incorporate the reduction of GHG emissions as a core element of compliance (para. 178).
Specific obligations under Article 194(1) UNCLOS
While mitigation was mentioned as being part of the necessary measures to prevent pollution of the marine environment, the Tribunal did not call for an immediate cessation of GHG pollution of the marine environment under Article 194. Instead, it acknowledged the accumulation of excessive GHGs in the atmosphere which will continue to harm the environment even after the cessation of emissions. It stated that compliance with the UNCLOS obligations requires States to take measures ‘with a view to reducing and controlling existing marine pollution from such emissions and eventually preventing such pollution from occurring at all’ (para. 199. Emphasis added). While thus giving some leeway for States’ respective capabilities to be taken into account, it does set a more strict obligation in stating that pollution through emissions must ultimately come to a halt.
The relationship between UNCLOS and the UNFCCC regime
In an effort to resist more stringent obligations relating to climate change under UNCLOS, some State Parties had contended that merely complying with the emission targets under the Paris Agreement was sufficient (para. 220). In this regard, the Paris Agreement sets out the overarching temperature goal of keeping global warming to ‘well below 2 degrees’ while pursuing efforts to limit such to 1.5 degrees was sufficient. The IPCC’s Sixth Assessment Report, however, has stressed the major differences of effects on the environment resulting from a temperature rise of 2 degrees as opposed to 1.5. Hence, the Tribunal’s reiteration of the 1.5 degree target and the separation of relevant obligations under UNCLOS from the UNFCCC regime is a crucial step allowing ITLOS to take a more stringent approach to climate change obligations (para. 209). Notably, the targets under the Paris Agreement are of a voluntary nature and the Convention, therefore, leaves considerable discretion to Member States as opposed to the legally binding nature of the provisions laid down in UNCLOS at issue in these proceedings.
Thus, it is of pivotal importance that the Tribunal interpreted the relationship between the UNFCCC, specifically the Paris Agreement, and UNCLOS, clarifying that the Paris Agreement does not in fact constitute lex specialis, and thus does not supersede State responsibilities towards climate change under UNCLOS. Instead, States have separate and independent obligations towards climate change arising from the interpretation provided by the Tribunal (paras. 223-224). In this regard, the objectives stipulated in the Paris Agreement complement the aims set out under provisions of UNCLOS, as the Tribunal clarified explicitly when analysing the obligation under Article 194(1) (para. 200).
The utilisation of climate science
On the role of climate science within the assessment of the obligations under UNCLOS, ITLOS stated that the assessment of whether States have taken all necessary measures to prevent the pollution of the marine environment must be ‘determined objectively’ in light of the ‘best available science’ (para. 243). In the Courtroom, ITLOS President Hoffmann expressly emphasised that States cannot determine these measures as they deem fit and further provided a broad interpretation of the term ‘necessary’ including ‘mitigation measures, central to which is the reduction of the release of GHG emissions into the atmosphere’ (minutes 27-31 of reading). The Tribunal added that this primarily includes the work of the IPCC, which reflects the scientific and State consensus (para. 208). This part of the Opinion constitutes an important step towards legitimising the scientific consensus and the use of climate science in climate litigation, which has been called into question by critics in previous climate litigation. Nevertheless, ITLOS clarified that in line with the precautionary principle, States cannot circumvent taking actions necessitated by the provisions and, thus, avoid international responsibility in cases of scientific uncertainty (para. 242).
Available means and the CBDR principle
ITLOS clarified that: ‘the reference to available means and capabilities should not be used as an excuse to unduly postpone, or even be exempt from, the implementation of the obligation to take all necessary measures’ (para. 226). Thus, it recognised the different capacities of State Parties, while additionally affirming that States may not rely on a lack of means in order to delay action in the first place. The Tribunal further explicitly established a link with the Common but Differentiated Responsibilities Principle, which forms a fundamental principle recognised under the UNFCCC and the Paris Agreement (para. 227). Consequently recognised the difference in scope of measures necessary by developing States in accordance with obligations under Article 194, as opposed to developed States who should ‘continue taking the lead’ (para. 229). This may materialise in regards to technical assistance for instance, whereby the Tribunal stated that ‘scientific, technical, educational and other assistance to developing States that are particularly vulnerable to the adverse effects of climate change is a means of addressing an inequitable situation’ (para. 327).
Nature of the obligation
On the nature of the obligation in Article 194(1) UNCLOS, the Tribunal interpreted it to be an obligation of conduct and, thus, a due diligence obligation (para. 233). As such, it must be considered in light of scientific and technological information, relevant international rules and standards and crucially, the high risk of serious harm to the environment and urgency of this issue (paras. 235-239 and 243). The Tribunal explicitly referenced the scientific consensus according to which GHG emissions and climate change pose a significant risk. Consequently, the Tribunal found that a stringent due diligence standard was to be applied. In this regard, the Tribunal further elaborated that an obligation of due diligence requires States to develop and implement ‘national legislation, administrative procedures and an enforcement mechanism’ (para. 235). Thus, while obligations of result are ordinarily more stringent, this interpretation not only forces States to take all necessary steps to comply with the provision, but the Tribunal additionally backed this obligation with the precautionary principle, as mentioned above (paras. 235, 242 and 243). Moreover, this obligation extends to transboundary impacts of pollution and States are required to prevent GHG emissions that harm the marine environment of other States, in accordance with Article 194(2) UNCLOS (para. 245).
Enforcement of obligations
Given that legal obligations must be enforced in order to be truly effective, it is of relevance that ITLOS highlighted States’ obligation to enforce their respective laws on the prevention of damage to the marine environment, which incurs international responsibility in case of infringements (para. 283). Furthermore, the Tribunal highlighted the necessity of carrying out monitoring practices and conducting environmental impact assessments in order to discern the potential detrimental impact of a planned activity on the marine environment, which has been recognised as customary international law (para. 352).
Obligation to ‘protect and preserve’
On the general obligation of States to protect and preserve the marine environment in accordance with Article 192, the Tribunal held that this obligation extends to all forms of degradation of the marine environment, including by way of the detrimental impacts of climate change, such as ocean warming, sea level rise, and the acidification of the oceans (para. 400). Notably, this provision further comprises the obligation to restore deteriorated habitats of the marine environment (para. 400). Thus, the obligation does not simply require States to cease and prevent polluting activities but to take further actions, in view of improving the state of the marine environment.
States’ obligations towards non-State actors
In regards to responsibilities of non-State actors, the Tribunal affirmed that States’ obligations laid down in Articles 192 and 194 mandate that they must ensure that non-State actors under their jurisdiction and control comply with the measures they have put in place to protect and preserve the marine environment (para. 396). Since this obligation is one of due diligence, States are required to exercise appropriate oversight and enforcement to prevent harm from non-State activities. Consequently, they can be held responsible if they fail to exercise due diligence and appropriate oversight over the actions of private actors.
Discussion: possible points of contention
Despite the progressive interpretations provided by the Tribunal highlighted above, certain aspects of the international debate around climate change were not sufficiently touched upon or entirely absent.
Human Rights and climate change
Of particular concern is the lack of reference to human rights. The Tribunal merely mentioned that: ‘climate change represents an existential threat and raises human rights concerns’ (para. 66). ITLOS did not elaborate further on the role of human rights concerns that are evoked by sea level rise or how this connects to the obligations under UNCLOS. In light of the fact that the procedure for the Advisory Opinion was set in motion by small island States, the resulting threat for human rights was arguably one of the main motivators for the request in the first place. Submitting parties, such as the United Nations Special Rapporteurs on Human Rights and Climate Change, Toxics and Human Rights and Human Rights and the Environment, specifically emphasised the role of human rights which must be considered within the interpretation of UNCLOS. The submission explicitly references the right to life, which is at stake in the face of climate change and should, therefore, inform the interpretations of UNCLOS (para. 24).
Lack of specific enforcement measures
In this regard, while the Tribunal highlighted the necessity for enforcement measures in order to ensure compliance with the respective obligations under UNCLOS, it did not identify specific enforcement measures. However, in its assessment of the requirements under Article 194 as an obligation of conduct, it also made clear that the standard of diligence ‘is stringent, given the high risks of serious and irreversible harm’ that it must be ‘determined objectively’ (para. 243). Thus, it set a high standard for States’ due diligence obligations and arguably put considerable pressure on States to ensure effective enforcement.
Determining specific obligations towards climate change
In a similar vein, the Tribunal did not elaborate further upon specific ways by which States could meet the obligation to prevent the pollution of the marine environment through GHG emissions. Arguably, the Court, therefore, did not concretise the specific obligations to the reduction and eventual cessation of polluting activities, thus seemingly avoiding politically contested topics, such as the phasing out of fossil fuels. Instead, the Tribunal vaguely noted that: ‘the IPCC defines the term “anthropogenic” as “[r]esulting from or produced by human activities” which “include the burning of fossil fuels, deforestation, land use and land use changes …, livestock production, fertilisation, waste management, and industrial processes”(...)’ (para. 54). Thus, the Tribunal did not explicitly push for concrete actions to be undertaken by State Parties.
On the other hand, the Tribunal’s balancing act concerning the legitimacy of the Advisory Opinion and potential pushback from State Parties must be taken into account. Additionally, climate science and the IPCC reports in particular could bridge this gap, whereby States must avail themselves of these knowledge bases and best available science to coordinate effective action against such pollution (para. 54). For this gap-filling function of climate science to become more effective, the Tribunal could have remarked on the increasing importance of attribution science to establish links between States’ conduct and climate change.
The role of the ITLOS Advisory Opinion for the ICJ Opinion
The Advisory Opinion is not only impactful for the 168 State Parties. In fact, many provisions of the Convention are considered customary international law and, thereby, applicable beyond its scope. Thus, the interpretation of UNCLOS may contribute in shaping the corpus of international law as such. Considering the uncertainty surrounding the interplay of legal regimes applicable to climate change within international law, the ITLOS Opinion has crucially clarified that States’ obligations on climate change exist outside of the UNFCCC Framework.
The Advisory Opinion has been issued at a time in which climate change and the resulting sea level rise has never been more threatening. In this regard, climate lawsuits and the issuance of advisory opinions by international courts represents a valuable tool to hold States accountable. Interpretations on the role of climate science in courtrooms and the clarification of the interlinkage of the manifold legal regimes applicable to climate change are, thus, of vital importance. Based on the foregoing, it may be confidently stated that the Advisory Opinion provides a strong foundation for the following Opinions, in view of strengthening the protection against climate change across all regulatory landscapes. The Tribunal solidified important arguments on which other courts may build upon. While the world is eagerly awaiting the outcomes of the remaining two advisory opinions, there is hope that these courts will elevate international obligations towards climate change further, providing especially small and developing island States with a strong tool to push for urgently required action.
Note about the authors:
Jasmine Rowe is a Master’s student in the field of Environmental Law in Europe at the University of Utrecht. She previously obtained a Bachelor degree in International and European Law, which sparked a particular interest in climate litigation and the way in which citizens increasingly mobilise the courts in order to hold States accountable.
Henrieke Bünger holds a LL.M in Environmental Law and a LL.B in International and European Law, focusing throughout on corporate accountability and climate litigation. She has since contributed to the advancement of legal research in these fields and has worked extensively in climate justice advocacy as well as youth engagement.