Pranav Ganesan, PhD candidate at the University of Zurich
Introduction
The ICJ, in its advisory opinion on the Obligations of States in respect of Climate Change (AO), makes several notable findings which are worth unpacking and assessing. In this blogpost, I will comment upon some of the Court’s findings related to the interpretation of states’ obligations arising from the 2015 Paris Agreement (Part IV.B of the AO).
Much of the Court’s engagement with the provisions of the climate treaties, in the part of the judgment answering the first question concerning the international obligations of States to protect the climate system and other parts of the environment, was limited to identifying whether they contained procedural or substantive obligations, and obligations of conduct or obligations of result. The most interesting findings of the Court were:
- That between the two temperature limits specified in the Paris Agreement (PA), viz. 2°C and 1.5°C (art. 2.1(a)), keeping the global average temperature increase below 1.5°C is the ‘primary temperature goal’ (para. 224); and
- That Paris Agreement Parties’ discretion to determine the substantive content of their nationally determined contributions (NDCs) is limited (para. 245).
In order to arrive at these conclusions, the Court resorted to the rules of interpretation as under the 1969 Vienna Convention on the Law of Treaties (VCLT).
1.5°C as the Primary Goal
Regarding the 1.5°C temperature limit, the Court considered the Glasgow Pact, as a ‘subsequent agreement’ between the parties to the Paris Agreement regarding its interpretation. Subsequent agreements between all parties to a treaty regarding its interpretation or application must be ‘taken into account’ together with the treaty’s context for the purposes of interpretation (VCLT, Art. 31(3)(a)). In other words, they must be thrown into the ‘crucible’ of all things that inform a treaty provision’s interpretation (see Declaration of Judge Tladi, para. 13). Readers may recall that the Conference of Parties (COP) held at Glasgow in the year 2021 aimed to keep the 1.5°C goal alive. The Glasgow Pact reaffirms Article 2.1(a) of the Paris Agreement, and then:
‘Recognizes that the impacts of climate change will be much lower at the temperature increase of 1.5 °C compared with 2 °C and resolves to pursue efforts to limit the temperature increase to 1.5 °C’ (para. 21, emphasis in the original).
The ICJ also relied on the 2023 UAE Consensus which ‘encourages Parties to come forward in their next nationally determined contributions with ambitious, economy-wide emission reduction targets, covering all greenhouse gases, sectors and categories and aligned with limiting global warming to 1.5 °C, as informed by the latest science, in the light of different national circumstances’ (Decision 1/CMA.5, para. 39).
Why is specifying the primacy of 1.5°C important? The mention of two different temperature limits in the Paris Agreement (a comprise formulation considering intractable disagreements between negotiating states) has been a source of some confusion. Mayer has argued that Article 2.1(a) can be explained as prescribing 2°C as the ‘real’ objective, with the States realizing that ‘achieving it is only possible if each of them implements the level of mitigation action that it sees as consistent with a 1.5°C target.’ Rajamani and Werksman have noted that: ‘[a]lthough there are differences in impacts between a 1.5°C temperature rise and a 2°C temperature rise, because the [PA’s] temperature goal is a single goal with two textually inseparable elements—the 1.5° C aspirational goal and the ‘well below 2°C’ goal—the implications of missing the goal are the same in relation to the implementation of the Agreement.’ The implications of missing the goal, according to the above authors, do not include state responsibility for individual Parties as Article 2.1 does not create legally binding obligations. However, there is no confusion as to the provision’s relevance for interpretation (which I shall get to in the next section).
Other international courts which have engaged with this provision have not been as clear about the primacy of the 1.5°C goal under the PA. In its KlimaSeniorinnen judgment, although the European Court of Human Rights noted as a general consideration that ‘the relevant risks are projected to be lower if the rise in temperature is limited to 1.5°C above pre-industrial levels’ (para. 436), it did not make normative statements suggesting 1.5°C as a quantitative temperature goal. In its findings as to the content of positive obligations under Article 8 of the European Convention on Human Rights (ECHR), it held that mitigation measures to be undertaken by ECHR parties must be aimed at preventing ‘a rise in global average temperature beyond levels capable of producing serious and irreversible adverse effects on human rights’ (para. 546). Admittedly, the Court’s factual finding regarding a +1.5°C warmer world could be taken together with this latter finding to imply that if the 1.5°C is crossed, the conclusion that human rights are seriously and irreversibly affected becomes obvious. Alternatively, the conspicuous absence of any mention of the 1.5°C threshold in the court’s conclusions as to ECHR parties’ positive obligations could be taken to imply that determination of what constitutes an unsafe level falls within each state party’s margin of appreciation as reduced by the consensus reflected in the PA and subsequent COP decisions (on the reduced margin of appreciation, see para 543). Under this line of reasoning, the Court could be seen as having shied away from putting forward its position on the issue of whether a consensus had arisen as to whether the lower of the two temperature goals is primary.
The International Tribunal on the Law of the Sea took a different route its advisory opinion where it was tasked with interpreting obligations under the 1982 UN Convention on the Law of the Sea related to addressing the deleterious effects of climate change on the marine environment. Regarding Article 194(1), the Tribunal interpreted the content of the duty to prevent, reduce and control marine environmental pollution via greenhouse gas emissions as requiring parties to undertake the necessary emission reduction measures while taking into account the 1.5°C goal in the PA (para. 243). It did so based on the ‘broad agreement within the scientific community that if global temperature increases exceed 1.5°C, severe consequences for the marine environment would ensue’ (para. 241). In other words, the ITLOS did not explicate that it regarded 1.5°C as the ‘primary goal’ under Article 2.1 of the Paris Agreement, although the advisory opinion could be understood as implying so. With the ICJ’s AO, this has now been made clear.
Just a few days before the ICJ gave its AO, the Inter-American Court on Human Rights (IACtHR) gave its advisory opinion on the ‘obligations of States in responding to the climate emergency.’ The IACtHR not only identified an obligation to regulate climate mitigation under the 1969 American Convention on Human Rights and 1988 San Salvador Protocol, but also went into detail as to what action states must take to comply with the same (para. 322 et seq). In this regard, it found there to be a ‘significant international consensus’ on keeping the global average temperature increase from exceeding beyond 1.5°C above pre-industrial levels. However, it added that even achieving this goal ‘does not eliminate the risk hovering over millions of people in the region’ (para. 326). As I had argued in a previous blogpost, there is nothing special about 1.5°C and 2°C, since they were merely a product of political compromise. Thus, the fact that the PA mentions these numbers does not necessarily lead to the conclusion that human rights law should be apathetic to the devastating impacts suffered by individuals and groups in a +1.4°C or +1.3°C warmer world. The threshold of warming that puts populations and ecosystems at ‘serious’ risk may vary from region to region. And the Inter-American Court affirmed this view. Still, since it had to specify a standard or otherwise risk leaving scope for ambiguity, the Court held that states must determine a mitigation target, based inter alia, ‘on a temperature increase of no more than 1.5ºC’ (para. 326). Again, the Court did not interpret Article 2.1(a) of the PA itself but rather used the provision, the international consensus and specific findings of the IPCC as to the risks of global warming exceeding the 1.5°C mark to help arrive at ‘a minimum starting point’ for what should inform national mitigation targets (para. 326). What is more, the language used by the Inter-American Court suggests no tolerance even for a limited overshoot above 1.5°C, in contrast to what seems to be suggested by the text of the UAE Consensus (see Decision 1/CMA.5, para 27).
Ultimately, the ECtHR, ITLOS and IACtHR avoided wading into the thicket of constructive ambiguity created by the mention of two temperature goals in Article 2.1(a) of the PA. Of course, they were only tasked with interpreting the ECHR, UNCLOS and ACHR respectively, and referring to the PA as a relevant instrument for interpretive purposes (VCLT, art. 31(3)(c)). Answering an interpretive question pertaining to an external treaty provision could have invited criticisms about the courts overstepping their jurisdiction. Moreover, the three courts in question may have chosen the ‘better safe than sorry’ approach, avoiding getting the interpretation of the PA wrong (before the ICJ could give its AO). Going forward, other courts may rely upon the findings in the AO about Article 2.1(a) PA, as well as its approach of using COP decisions as interpretive tools.
The Content of NDCs
The primacy of ‘national determination’ of mitigation contributions under the Paris Agreement (also called the ‘bottom-up approach’) has led to concerns about the toothlessness of the treaty. Indeed, while Article 4.2 creates a binding obligation on Parties to prepare and communicate NDCs, the committee tasked with reviewing compliance with this obligation cannot comment on their substantive (in)adequacy (Decision 20/CMA.1, Annex, para. 23). Moreover, the wording of Article 4.2 does not directly suggest that these NDCs must be highly ambitious or determined with concern for those most vulnerable to the effects of global warming. However, the ICJ held that ‘[t]he content of the NDCs is equally relevant’ to the formal preparation, communication and maintenance of successive NDCs ‘to determine compliance’ (para. 236).
The Court’s interpretation of Article 4.2 PA was based on other provisions of the Paris Agreement as well as COP Decisions. The following provisions were cited as providing support to the Court’s interpretation: Article 2 (setting out the Parties’ collective goals and manner of implementation of the PA), Article 3 (defining NDCs); Article 4.3 (setting out the normative expectation of progression and highest possible ambition); Article 14.3 (linking the outcomes of the global stocktake with NDCs) and Article 4.8 (linking information to be communicated through NDCs with COP decisions). Additionally, the Court relied on a requirement under the Paris Rulebook (adopted during the 2018 Katowice COP) that Parties must explain how they consider their contribution to be fair and ambitious, and how it contributes to the objectives of the 1992 UN Framework Convention on Climate Change and Paris Agreement as set out in Article 2 of both treaties (Decision 4/CMA.1, Annex I, paras. 6-7). The Court’s reasoning on limited state discretion in determining the content of their NDCs is reminiscent of its reasoning in the Whaling judgment, relating to the question of whether the International Whaling Convention gives parties absolute discretion to determine whether their conduct falls within the ‘purposes of scientific research’ exception (see paras. 56-61). In both instances, the Court balanced the discretion-preserving intent suggested by the wording of the provisions against the treaties’ other-regarding object and purpose. And why is the ICJ’s finding that Parties’ discretion to self-regulate climate mitigation is not absolute important? As Judge Tladi noted in his declaration, this means that the ambitiousness (or sufficiency) of NDCs is ‘open to scrutiny, including judicial scrutiny’ (para. 17, emphasis added).
Concluding Remarks
This blogpost has highlighted two key findings of the ICJ regarding provisions of the PA. Parties must align the mitigation contributions they communicate with the 1.5°C goal as well as other standards under the PA such as progression, highest possible ambition, and the principle of common but differentiated responsibilities and respective capabilities (CBDR-RC). Given that objectives specified in NDCs need to be implemented with due diligence through domestic measures (PA, art. 4.2 second sentence), these findings will embolden domestic courts in reviewing such measures.
