Climate Displacement in the ICJ’s Advisory Opinion

The ICJ’s Advisory Opinion of 23 July 2025 is momentous, affirming that climate change can give rise to breaches of international obligations under both customary and treaty law, including environmental, human rights, and UNCLOS frameworks. These obligations apply individually and collectively, with attention to the specific vulnerabilities of affected States. However, when it comes to iterating the specific challenge of displacement arising from climate impacts, particularly in the context of sea level rise affecting Small Island Developing States (SIDS), the Court’s treatment is limited and peripheral.

The Court recognises that sea level rise threatens the territorial integrity of SIDS and low-lying coastal states, implicating their permanent sovereignty over natural resources and loss of territory (paras. 357, 363). The Court further notes that forced displacement, both internal and cross-border, is among the adverse impacts of climate change in this context. Here, the Court references the Ioane Teitiota case, acknowledging that displacement may trigger the principle of non-refoulement under Article 6 of the International Covenant on Civil and Political Rights (ICCPR), where return would expose an individual to a real risk of irreparable harm to the right to life, signalling the relevance of human rights norms in addressing climate displacement (para. 378).

However, beyond this brief recognition, the Court does not clarify the legal consequences of displacement for countries of origin and host states. While the Court addresses other obligations such as the duty to cooperate, state responsibility, and loss and damage elsewhere in the opinion, these are not explicitly connected to the need to prevent or respond to displacement arising in such contexts. As a result, climate displacement as a systemic, foreseeable, and politically urgent phenomenon remains unresolved and underdeveloped in the Court’s reasoning. In this regard, Judge Aurescu, in his separate opinion, characterises the Court’s analysis of non-refoulement as ‘incomplete’, suggesting that it could have been strengthened by addressing the positive obligations of states to take proactive measures to prevent refoulement and to ensure that rights of displaced persons in host countries are protected and fulfilled (paras. 25-6). The following sections offer some initial reflections on key areas relevant for cross-border climate displacement that merit deeper engagement.

Displacement Framed as Peripheral 

Displacement as an issue appears in the Court’s opinion primarily as a consequence of the adverse effects of climate change, including extreme weather events, sea level rise, land degradation, coastal erosion, ocean acidification, and glacial retreat (p.8 preambular para. 7). As recorded by the Court, these impacts are leading to displacement of affected persons and further threatening food insecurity, water scarcity, loss of livelihoods, and hindering efforts toward poverty eradication and sustainable development. In the context of SIDS and low-lying coastal States, the Court links sea level rise to both internal and cross-border displacement, alongside the erosion of territorial integrity and permanent sovereignty over natural resources (para. 357).

While the Court establishes a factual link between displacement and climate change, it does not  recognize climate displacement as a distinct legal phenomenon situated within the broader ecosystem of international migration law. As one of many drivers of internal and cross-border movement, climate change raises complex questions of legal status and entitlement to international protection, requiring engagement with multiple legal regimes, including the 1951 Refugee Convention and its 1967 Protocol, which in this case may not be applicable, as it requires a well-founded fear of persecution arising from one of the five specific grounds of race, religion, nationality, membership of social group, or political opinion; or complementary and subsidiary protection frameworks in international human rights law; or regional instruments such as the 1969 OAU Convention and the 1984 Cartagena Declaration, which extend protection to persons displaced by natural disasters; or even soft law instruments such as the Nansen Initiative and the Platform on Disaster Displacement. Determining legal protection for such persons requires a nuanced legal analysis that considers both the causes of displacement and the interpretation of the scope of the above instruments in light of harm from climate change. In the absence of such analysis, the treatment of displacement in the Court’s opinion remains peripheral.

Moreover, several States, in their written submissions, presented climate displacement as a pressing and multifaceted issue, a context that frames the background against which the Court’s opinion was delivered. Vanuatu argued that reparations include not only monetary compensation but also restitution and non-monetary forms of redress for displacement-related harms. Kiribati highlighted the gendered dimensions of climate displacement, noting that nearly 80 percent of those displaced are women and children. Tuvalu, in its submission, drew attention to the destruction of coastal infrastructure caused by extreme weather events, referencing Tropical Cyclone Pam in 2015, which displaced nearly half its population. Likewise, for Bangladesh, climate displacement poses an incremental threat of loss and damage, placing strain on its capacity to finance adaptation measures. In these submissions, displacement is portrayed not merely as physical relocation, but also as a profound loss of place, property, identity, and culture. Yet, the Court’s reasoning fails to capture the full gravity of climate displacement as a systemic and existential threat, particularly for the most vulnerable states. 

Teitiota and the Limits of Non-Refoulement

With its reference to Ioane Teitiota v New Zealand, the Court reiterates the UN Human Rights Committee’s finding on the application of the principle of non-refoulement, recognising that the effects of climate change may, in certain circumstances, trigger obligations under Article 6 of the ICCPR (para.378). However, the Court could have used this opportunity to engage more fully with the legal uncertainties that Teitiota has generated, particularly the contested question of whether the applicable standard for protection requires a risk that is ‘imminent.’ As Foster and McAdam have discussed, while the threshold remains one of ‘real risk,’ the framing in Teitiota has led to confusion and inconsistent interpretations of the standard over time. This clarification could be especially critical for SIDS, where climate impacts such as sea level rise and the degradation of arable land unfold gradually but are nonetheless serious and foreseeable. This aligns with the HRC General Comment 36, which recognises that foreseeable threats and life-threatening situations can engage Article 6 without requiring imminence or actual loss of life (para. 7).

More broadly, the principle of  non-refoulement, while integral to international protection, is only one step among a range of protections in addressing climate displacement. As an individualised and reactive safeguard, it applies at the point of return and offers no durable solutions or preventive protection for communities at risk. As Judge Aurescu observes in his separate opinion, the Court might have clarified how the principle of non-refoulement could be complemented by other obligations such as the duty to conduct individualised risk assessments, obligation of admission, issuance of temporary visas, planned relocation, etc (para. 26). Thus, the Opinion leaves open key questions about how persons facing cross-border displacement can be protected under international law. 

Missing Connections to Displacement: Statelessness, International Cooperation and Loss and Damage

The ICJ’s Advisory Opinion affirms a range of obligations on States to protect the climate system and to uphold the rights of present and future generations. However, it does not engage directly with how these obligations apply to the issue of displacement. There are at least three areas where such a connection is relevant but insufficiently addressed: statelessness, international cooperation, and loss and damage.

The Court rightly affirms that the disappearance of territory due to sea level rise does not necessarily lead to the loss of statehood, thereby supporting the continuity of statehood and maritime entitlements (paras. 355-65). However, the Opinion does not address the fate of displaced populations who may no longer reside within the physical territory of their State. This is an important gap, particularly for SIDS, where the risk of entire communities being forced to relocate raises urgent questions regarding nationality, how they might access their rights, and the prevention of statelessness. While the Court acknowledges the link between sea level rise and the right of self-determination, it does not clarify how this right will be realised for persons who might be territorially detached from their State. A notable example here is the Australia-Tuvalu Falepili Union Treaty, which both recognises Tuvalu’s continuing statehood and sovereignty notwithstanding the impact of sea-level rise (art. 2(2)(b)) and creates a special human mobility pathway enabling citizens of Tuvalu to live, study and work in Australia with access to Australian education, health, income and family support on arrival (art. 3), thus linking preservation of statehood to pathways of residency. 

Likewise, the Court affirms that the duty to cooperate is a self-standing rule of customary international law, grounded in the United Nations Charter and widely reflected in treaties and declarations (paras. 140-42). It upholds the importance of coordinated international action to prevent significant harm and to protect the global environment. Yet the Opinion does not indicate how this duty might function in response to climate displacement. By contrast, instruments such as the 2016 New York Declaration for Refugees and Migrants and the 2018 Global Compact for Migration stress that international cooperation, through capacity-building, financial support and responsibility-sharing, is essential in responding to migration.

In relation to loss and damage, the Court confirms that Article 8 of the Paris Agreement provides a basis for cooperative support, while noting that it does not establish liability or compensation (paras. 414-20). This interpretation aligns with the approach taken in previous COP decisions, but leaves unresolved the question of how displacement is to be addressed. Displacement is increasingly recognised as a form of non-economic loss within the loss and damage framework by the UNFCCC, and the Warsaw International Mechanism for Loss and Damage includes a dedicated Task Force on Displacement. Nonetheless, the Court offers limited guidance on how this framework might evolve to address the irreversible consequences of climate displacement.

The IACtHR on Climate Displacement: A Comparison

By comparison, the Advisory Opinion of the Inter-American Court on Human Rights (IACtHR) of May 2025 on the climate emergency and human rights treats climate-related human mobility as an independent rights question under Article 22 of the American Convention on Human Rights, which addresses freedom of movement and residence (paras. 414-417). It articulates duties of states in this regard, including on family unity and specific safeguards for children (paras. 428, 434), to legislate and govern planned relocations through adequate human rights framework that assigns institutional responsibilities and provides comprehensive reparations for affected persons (paras. 425-429), to enable safe and regular cross-border mobility (para. 432), to create admission categories such as humanitarian visas, temporary residence, or refugee-analogous protection, to secure non-refoulement (para. 433), to provide consular and humanitarian assistance within a cooperation mandate(paras. 430-432). Importantly, the IACtHR frames human mobility within the loss and damage architecture. It reviews Article 8 of the Paris Agreement, the Warsaw International Mechanism and the new Loss and Damage Fund (paras. 199-201) and urges the operationalisation of international funds so vulnerable countries can cope with human mobility generated by climate change (para. 431). Thus, the IACtHR goes further in developing rights-based blueprint for climate displacement that states can implement, both to prevent and as long- term solutions (para. 433). However, like the ICJ’s Advisory Opinion, the IACtHR does not substantially elaborate beyond the Ionae Teitiota’s non-refoulement standard, which it cites in this context (paras. 433, fn. 734). 

Conclusion 

This Advisory Opinion clearly marks a landmark development in clarifying the legal obligations of states and the legal consequences arising from climate change under international law. While displacement was not the sole focus, the reasons outlined above demonstrate how a closer engagement with this issue would have strengthened the Court’s contribution to shaping a comprehensive legal response that better protects the rights of persons displaced by climate change. At the same time, the Court’s recognition of human rights dimensions of climate change may also be read as a judicial opening, one that implicitly invites international and regional human rights treaty bodies and national courts to existing protections more expansively in response to climate displacement.