Disaster Passing as Miracle? A Critical Take on the ICJ’s Climate Advisory Opinion

I – Introduction

George Monbiot – one of Britain’s most prominent public intellectuals and environmental campaigners – once remarked of the Paris Agreement: ‘by comparison to what it could have been, it’s a miracle. By comparison to what it should have been, it’s a disaster’. Judged narrowly through the lens of climate diplomacy and against the spectacular failure of the Copenhagen summit, the Agreement’s mere existence was heralded as a triumph. Yet behind the applause and self-congratulation, Monbiot warned, lurked an instrument marred by ’squalid retrenchments’, one that tolerates the continued expansion of fossil-fuel production and evades the structural causes of climate change.

A decade on, the International Court of Justice long-anticipated Advisory Opinion on climate change is eliciting effusive praise. Headlines celebrate it as a ‘historic legal victory’ for climate justice, a ‘landmark decision’, and even a ruling that ‘ends the era of climate impunity’. In this post, I wish to argue that these hyperbolic reactions are not only misguided but also counterproductive and potentially dangerous. Like Monbiot, I worry that we have become so accustomed to the chronic underperformance of international environmental law – decades of delay, diplomatic theatre, and weak regulation – that we have lost the ability to distinguish genuine progress from mediocrity. What is, on close inspection, a weak opinion – riddled with omissions, inconsistencies and banalities – passes as a miracle.

This post proceeds as follows. Part II highlights a handful of the ICJ’s pronouncements that might be cast as ‘wins’ for the climate, while emphasizing their inherent limitations. The post then goes on to outline the opinion’s main weaknesses, including its unduly narrow framing of the question posed by the General Assembly (Part III) and areas where the Court’s answers are, at best, unhelpful and, at worst, regressive (Part IV). I conclude with a few thoughts on the hazards of sugar-coating international law’s deficiencies and overstating the transformative potential of climate litigation.

II – A few (qualified) wins for the climate?

The Court’s opinion contains a handful of climate ‘wins’, some symbolic and others modestly substantive.

Symbolically, the unanimity of the Court is notable. Unanimous decisions are a rare feat in international proceedings. That the ICJ adopted the entire operative part of the opinion without dissent sends a signal of collective recognition of the threat posed by climate change and the role international law has to play in tackling it.

Yes this symbolic triumph is fragile. Eleven judges issued separate opinions or declarations, many voicing dissatisfaction with the opinion’s lack of ambition, vagueness, or narrow scope. Judge Yusuf’s scathing critique – describing the opinion as ‘rooted in extreme formalism and completely detached from the empirical realities and scientific findings relating to the causes and consequences of climate change – is a dissent in all but name.

More fundamentally, the Court’s much-touted unity was achieved at the expense of depth and relevance. As noted by Judge Aurescu, on most substantive issues the Court’s reasoning is ‘excessively and unnecessarily cautious and minimalist’. The Court’s avoidance of hard questions – such as whether the continued expansion of fossil-fuel production is compatible with States’ due diligence obligations – undermines the opinion’s normative potential, a point to which I return below.

Substantively, the Court clarified the Paris Agreement’s temperature goal. The Agreement famously enshrines a dual target: to hold temperature increases ‘well below 2°C above pre-industrial levels’ while ‘pursuing efforts’ to limit the rise to 1.5°C. This compromise formulation left interpretative uncertainty over which figure sets the benchmark for assessing State action. The ICJ, relying on recent COP decisions referencing 1.5°C as the singular target and construing these as ‘subsequent agreements’ under Article 31(3)(a) VCLT, concluded that 1.5°C is now ‘the parties’ agreed primary temperature goal’ (para. 224). While not revolutionary – ITLOS and the Inter-Amercian Court of Human Rights have reached similar conclusions in their own climate change opinions – this represents the most authoritative confirmation to date of 1.5°C as the operative benchmark.

The opinion is also notable for its firm rejection of some of the most extravagant arguments advanced by major emitters, for instance that traditional rules on transboundary pollution don’t apply to climate change, that climate treaties are the exclusive source of relevant obligations, or that the Paris Agreement grants States unfettered discretion over the ambition of their climate policies.

The attraction of these positions for large emitters is easy to understand. The Paris Agreement established a weak governance architecture: its obligations are largely procedural, it contains no binding quantitative targets, and it lacks any formal enforcement mechanism. Framing it as the ‘only game in town’ shields gross emitters from broader accountability. As for the ‘unfettered discretion’ thesis, it would turn the Agreement into an instrument of self-regulation, delegating to states the unilateral power to define – and limit – their own climate obligations.

The Court rejected these claims, holding that climate treaties coexist with other bodies of international law, including human rights, the law of the sea, customary due diligence, and the general law of state responsibility (paras. 162-72 and 410-8). It further interpreted the Paris Agreement – read in light of object and purpose – as requiring NDCs ‘capable of meeting’ the 1.5°C temperature goal (paras. 242-6). This means that their adequacy can be assessed against objective standards and legally reviewed.

However, these victories should not be overstated. The arguments dismissed were fringe and opportunistic, advanced in litigation rather than reflective of settled state practice, and few expected them to succeed. The Court also weakened its findings by its own caveats. On the lex specialis question, for example, the Court robustly denied that climate treaties displace general international law, only to add that a state’s compliance with its treaty obligations ‘suggests that this state substantially complies’ with customary duties to prevent environmental harm (para. 314). Despite efforts by some judges to downplay this passage (Tladi, para. 22; Nolte, para. 13), it reads like lex specialis by another name – or perhaps ‘lex specialis light’. Even as a rebuttable presumption, this formulation downgrades the autonomous force of customary law and risks encouraging states to argue that meeting their (mostly procedural) Paris obligations suffices to discharge their broader duties under international law.

III – Crumbs for the Global South: the Court’s re-writing of the request

Beyond these limited gains, much of the opinion offers little reason for celebration. The Court’s most fundamental shortcoming lies in its narrow interpretation of the General Assembly’s request, a choice criticized by several judges (see Sebutinde, paras. 3-6; Yusuf, paras. 1-9). The request, initiated by Vanuatu, was framed with a strong climate justice orientation. It foregrounded the stark asymmetry in historical responsibility for emissions, the disproportionate impacts on vulnerable states, and their more limited capacities to respond. Question (b) explicitly asked the Court to determine the legal consequences for states that ‘have caused significant harm to the climate system’ vis-à-vis states that ‘are injured or specially affected by or are particularly vulnerable’ to climate impacts [emphasis added].

Despite this, the Court carefully avoided identifying the responsibility of any particular states or categories of states. Instead, it provided an abstract recitation of the general rules on state responsibility (paras. 106-8), insisting that customary law ‘does not differ depending on the category or status of an injured state’ and that climate vulnerable states are ‘entitled to the same remedies as other injured states’ (para. 109).

This formalist approach erases the distributive inequities central to the request and sidesteps the differentiated consequences that could follow from recognizing the asymmetry between gross emitters and vulnerable states. This reticence also foreclosed the Court from grappling meaningfully with several key arguments made by small islands and vulnerable states, including claims relating to the legal protection of climate refugees, the preservation of maritime entitlements, or the continuity of statehood in the face of rising sea-levels.

The Court’s pronouncements on these issues were fragmentary, largely gestural and confined to isolated dicta. Its discussion of climate displacement occupies a single paragraph (para. 378), invoking non-refoulement but omitting the positive protective duties recognized under international human rights law. On maritime entitlements, it stated that UNCLOS does not compel states suffering land loss to unilaterally revise their baselines (para. 359), but avoided declaring such baselines fixed or permanent. Its remarks on statehood were even more elliptical, stating only that the disappearance of a state’s constitutive element ‘would not necessarily entail the loss of its statehood’ (para 363). This pronouncement was delivered with no supporting rationale or explanation, leaving the reader, in Judge Tomka’s words, ‘to ponder [the Court’s] Delphic pronouncement, unaided by any reasoning whatsoever’ (para. 11).

While these dicta will undoubtedly provoke rich scholarly debate, they offer cold comfort to communities confronting imminent displacement, the destruction of their livelihoods, or the literal disappearance of their homeland beneath rising seas.

IV – A Text Riddled with Platitudes, Silences, and Regressions

Perhaps the most striking feature of the opinion is its pervasive reliance on platitudes, its studied silences on the most urgent legal questions, and occasional regressions that risk weakening, rather than strengthening, the international legal response to climate change.

Large sections of the opinion rehearse familiar statements about climate change’s severity, the importance of cooperation, and the need for urgent action, without substantive legal analysis. The opinion’s operative reasoning often consists of truisms or restatement of consensus language drawn from COP decisions, IPCC reports, UN Declarations or treaty provisions. Paragraphs that might have clarified the substantive content of states’ obligations frequently dissolve into non-committal affirmations that states must ‘take all appropriate measures’ or ‘act with due regard’ to the climate system, and that failure to do so ‘may constitute an internationally wrongful act’ – formulations that do little to guide conduct or assess compliance.

The Court’s analysis of the duty to pursue domestic mitigation measures under the Paris Agreement, to cite but one example, culminates with the following banality, which is emblematic of the opinion’s tendency to inflate the obvious while shying away from the hard questions: ‘the obligation […] requires states to be proactive and pursue measures that are reasonably capable of achieving their NDCs. These measures may include putting in place a national system, including legislation, administrative procedures and enforcement mechanisms, and exercising adequate vigilance to make such a system function effectively’ (para. 253).

Equally troubling are the silences that permeate the opinion. The Court avoided addressing several pressing issues raised during the proceedings, including:

• Emissions accounting, in particular whether states are responsible for mitigating not just territorial emissions but also embedded and downstream (‘scope 3’) emissions (on which see Xue, para. 74; Bhandari and Cleveland, paras. 16-23);
• Whether new fossil fuel expansion is compatible with due diligence obligations (on which see Bhandari and Cleveland, paras. 4-10);
• Climate finance, including whether quantum targets expressed in COP Decisions are binding.

By declining to articulate clear standards on these questions, the Court offers only broad exhortations where specific standards are most needed.

In some instances, these silences amount to implicit regressions from more ambitious rulings. On the matter of NDCs and states’ mitigation ambitions, for example, certain domestic courts have required governments not just to reduce emissions but to align mitigation pathways with scientific trajectories, occasionally mandating quantified targets derived from IPCC scenarios. More recently, in Verein KlimaSeniorinnen Schweiz v Switzerland, the European Court of Human Rights held that states’ mitigation policies must, at minimum, be grounded in a clearly quantified ‘fair share‘ carbon budget with time-bound reduction targets.

By contrast, the ICJ avoided endorsing any quantitative obligation or trajectory, contenting itself with the anodyne conclusion that states must adopt measures ‘capable of making an adequate contribution’ to achieving the temperature goal (para. 242) – without clarifying how adequacy is assessed or whether NDCs must align with scientific consensus or IPCC emissions scenarios. The ICJ’s silence on the rich body of domestic and regional climate judgments – such as Urgenda or Neubauer – can be seen as another ‘Arrest Warrant’ moment, echoing the Court’s then refusal to engage with the progressive positions of the UK House of Lords in the Pinochet ruling. By sidestepping this jurisprudence, the Court signals a reluctance to integrate the evolving judicial consensus on states’ mitigation obligations into its reasoning.

V – Conclusion: Against Sugar-Coating

The ICJ’s Climate Change opinion is, at best, a mixed legacy. It contains modest gains – such as clarifying the Paris Agreement temperature goal and rejecting fringe claims by large emitters – but these are outweighed by platitudes, conspicuous silences, and doctrinal regressions. By declining to articulate clear standards for state conduct and retreating from the more ambitious positions of domestic and regional courts, the ICJ has delivered an opinion that gestures toward history but ultimately settles for minimalism.

None of this is to deny the structural constraints under which the Court operates. The Court depends on state consent for its authority; and genuine judicial boldness in the face of great-power opposition carries political and institutional risks (on which see Nolte, para. 32). In this sense, a conservative opinion was always a foreseeable outcome. Yet structural limits do not transform caution into achievement. A weak opinion does not become a landmark simply because it exists, nor does its adoption automatically signal a ‘new era’ of climate accountability.

Celebrating such an opinion as a ‘historic breakthrough’ risks entrenching a culture of low expectations and incrementalism, where modest statements are treated as transformative and meaningful change is deferred indefinitely. In doing so, we may unwittingly participate in the same cycle of self-congratulation and symbolic politics that has long characterized the spectacle of global environmental governance.

As legal scholars, our task is not to euphemise shortcomings or pass off conservative decisions as ground-breaking. It is to explain, contextualise and critique where necessary, ensuring clarity about what international law currently offers – and withholds – in the face of climate breakdown. Critical engagement, rather than celebratory hyperbole, is what ultimately serves the twin goals of legal scholarship and climate justice.