By Ayyoub (Hazhar) Jamali, postdoctoral researcher at the University of Zurich
1. What the Court Said
In its Advisory Opinion of 23 July 2025, the International Court of Justice (ICJ) addressed, among other matters, the scope of States’ obligations under international human rights law in relation to climate change. A central, though implicitly framed, issue was whether States bear extraterritorial human rights obligations for climate-related harms affecting individuals beyond their borders.
In the section titled “Territorial scope of human rights treaties” (paras. 394–402), the Court recalled its previous jurisprudence recognizing that human rights treaties may apply extraterritorially when a State exercises jurisdiction outside its own territory. The ICJ reaffirmed that this interpretation applies in the context of the ICCPR, referencing its 2004 Wall Advisory Opinion and its 2005 Judgment in Armed Activities on the Territory of the Congo, as well as its 2024 Advisory Opinion on the Occupied Palestinian Territory.
Quoting the Wall Opinion, the Court confirmed that Article 2(1) of the ICCPR may cover individuals outside a State’s territory but subject to its jurisdiction, based on the object and purpose of the Covenant and the drafters’ intention (travaux préparatoires) not to allow States to escape responsibility when exercising jurisdiction abroad.
The Court also reiterated prior interpretations of other treaties:
- The ICESCR, while lacking an express territorial clause, may apply both to sovereign territory and to territory under the State’s jurisdiction (para. 400).
- The Convention on the Rights of the Child applies to “each child within their jurisdiction”, and was held applicable in the “Occupied Palestinian Territory” (para. 401).
Despite this, the Court stopped short of determining under what conditions a State exercises jurisdiction extraterritorially, stating that such analysis must be treaty-specific. Importantly, it distinguished between treaty law and customary international law (para. 402), signaling that the two frameworks may diverge in how they address jurisdiction and obligations.
2. Gaps and Unresolved Questions
The Court’s treatment of whether, and under what conditions, States have extraterritorial human rights obligations for climate-related harm reveals several significant analytical and normative gaps.
First, while the Court engaged with the treaty body jurisprudence, it refrained from offering judicial analysis or placing those views within a broader doctrinal framework. The ICJ’s passive approach left open the question of whether States accept these extraterritorial interpretations or whether they are mere soft law positions. In this context, it should be noted that the ICJ’s advisory function is not limited to summarizing existing legal positions; it carries a responsibility to offer authoritative guidance on unresolved or contested points of international law. In this case, where significant interpretive uncertainty surrounds the extraterritorial application of human rights obligations in the climate context, the Court had a rare opportunity to provide clarity. Instead, it recited existing jurisprudence without taking a clear position, leaving core questions — such as the legal status of treaty body interpretations or the threshold for extraterritorial jurisdiction — largely unaddressed.
Second, the Court made no attempt to tailor its discussion to the particularities of climate change, despite its inherently transboundary nature. It did not engage with concrete examples where extraterritorial obligations might arise. For instance, consider a scenario where State A, a major emitter of greenhouse gases, fails to regulate its fossil fuel industry. As a result, rising sea levels and intensified storms displace communities in State B, a low-lying island nation. Does State A have extraterritorial human rights obligations toward individuals in State B, given the foreseeable and science-based nature of the harm? This is precisely the kind of factual matrix where environmental law principles (such as the no-harm rule) might intersect with human rights obligations. Yet, the Court did not explore whether such functional or effects-based jurisdiction could be justified in the climate context.
Third, a notable omission in the ICJ’s Opinion is its failure to engage with relevant jurisprudence from regional human rights courts. Most significantly, the Court made no reference to the ECtHR’s 2024 Duarte Agostinho judgment, which directly addressed the question of extraterritorial human rights obligations in the context of climate change. In that case, the Strasbourg Court rejected an expansive reading of jurisdiction that would cover transboundary climate impacts. The ECtHR adhered to the traditional “control over the victim” model, expressing concern that adopting a “control over the source” approach would effectively turn the ECHR into a global climate change treaty.
In contrast, the ICJ remained silent. Given its universal mandate and its stated role in clarifying international law, even a brief engagement with Duarte Agostinho would have enriched the Opinion’s doctrinal relevance and provided a valuable comparative perspective. The omission may reflect institutional restraint: acknowledging a controversial regional judgment could be seen as implicitly endorsing—or rejecting—a contested interpretive move.
Fourth, in paragraph 402, the Court underscored a doctrinal distinction between treaty law and customary international law, stating that they must be analyzed separately. While the Court did not elaborate, this statement is more than a procedural clarification — it has important implications for the future development of extraterritorial obligations in the climate context.
Unlike treaties, which are based on explicit consent and often contain jurisdictional clauses (such as Article 2(1) of the ICCPR), customary international law is grounded in general practice accepted as law (opinio juris) and may evolve independently of treaty frameworks. By distinguishing the two, the Court subtly acknowledged that even if human rights treaties do not currently impose extraterritorial obligations in climate cases, customary law might still do so in the future — especially where transboundary harm is foreseeable and scientifically attributable (see para. 429).
This distinction could justify a different interpretive posture: the Court may be unwilling to extend extraterritoriality under treaty law due to concerns about textual fidelity and state consent, but customary law offers more normative flexibility. This is particularly relevant in the context of climate change, where global harm arises from cumulative emissions, not isolated acts, and where rigid territorial frameworks struggle to reflect real-world causal chains.
Moreover, the ICJ’s separation of treaty and customary law might also reflect institutional caution. Endorsing a customary rule allowing for extraterritorial environmental responsibility (without explicit treaty basis) could be seen as less politically provocative than redefining treaty obligations. Thus, the Court may be laying groundwork for future claims based on customary principles like the no-harm rule, the duty to cooperate, or emerging norms linking environmental harm to the enjoyment of human rights.
3. Conclusion
The ICJ’s restrained approach to extraterritoriality in the climate context is both telling and incomplete. Its silence reflects a delicate balancing act. While the Court reaffirmed universal obligations under customary international law (e.g., the duty to cooperate, the duty to prevent significant transboundary harm, and the erga omnes nature of climate obligations) it stopped short of clarifying whether these obligations entail extraterritorial jurisdiction in specific cases. In doing so, the Opinion preserves an appearance of judicial deference while simultaneously inviting further litigation and interpretation by regional courts and treaty bodies.
Nevertheless, the Opinion leaves room for legal development—whether through future litigation, the evolution of treaties, or the formation of customary law. The challenge now facing courts, States, and advocates is to ensure that this legal space does not remain undefined for too long.