Displacement in the ICJ's Advisory Opinion on Climate Change

Abstract

In its 2025 Advisory Opinion on climate change, the International Court of Justice acknowledged that displacement is among the ‘severe and far-reaching’ consequences of climate change and affirmed that the principle of non-refoulement applies in this context where life-threatening conditions prompt people to seek international protection elsewhere. This article explores how the court's findings embed existing legal authority, and, importantly, how the court's recognition of the interconnectedness between international human rights law, environmental law and climate change law may open up new lines of argument for future international protection claims.

Introduction

The 2025 Advisory Opinion of the International Court of Justice (ICJ) on climate change is groundbreaking in many respects. Even in areas where its analysis is limited – such as displacement in the context of climate change – its authoritative affirmation of existing jurisprudence is valuable. The ICJ confirmed that the principle of non-refoulement applies where life-threatening ‘conditions resulting from climate change’ prompt people to seek protection elsewhere or preclude them from returning home. ¹ Furthermore, the court's recognition of the interconnectedness between international human rights law, environmental law and climate change law has the potential to open up new lines of argument when it comes to international protection claims in this context. ²

Since the court was not formally requested to advise on States’ obligations with respect to displacement, ³ it is unsurprising that its express analysis of the issue is scant. However, it did acknowledge that displacement is among the ‘severe and far-reaching’ consequences of climate change, which pose an ‘urgent and existential threat’. ⁴ It also observed that ‘sea level rise is likely to have adverse consequences for States, particularly small island States and low-lying coastal States, potentially leading to the forced displacement of populations within their territory or across borders, as well as affecting the territorial integrity of States and their permanent sovereignty over their natural resources’. ⁵

Beyond this, the Advisory Opinion contains four key findings of particular relevance to this context. First, as noted above, the court affirmed existing jurisprudence concerning States’ non-refoulement obligations in the context of climate change – namely, that people may qualify for international protection where the adverse impacts of climate change pose a real risk to their lives. Secondly, the court recognized that people have a right to a clean, healthy and sustainable environment, and that this ‘is a precondition for the enjoyment of many human rights’. ⁶ Thirdly, it underscored the centrality of the duty to cooperate, including in relation to adaptation and, potentially, climate mobility. Fourthly, it acknowledged that even if a State loses territory or population as a result of sea-level rise, this does ‘not necessarily entail the loss of its statehood’. ⁷

The article begins with a brief introduction to displacement in the context of climate change, before examining each of the four elements in turn. It seeks to explain how the court's findings draw upon and embed existing legal authority, and how they could support the further development of key legal principles in the context of climate mobility.

Displacement in the Context of Climate Change

Each year, more people are displaced internally by disasters than by conflict – a trend that has been consistent for more than 15 years. ⁸ Although there are no reliable figures on cross-border displacement related to the impacts of climate change and disasters, largely due to methodological challenges with compiling such data, these impacts feature in an increasing number of international protection claims. Displacement can exacerbate and generate both individual and collective risks, causing profound disruption and adversely impacting a range of human rights, including the rights to life, water, food, health, work, education, shelter and a clean and healthy environment. According to the Kaldor Centre Principles on Climate Mobility, ‘[w]hen considered alongside pre-existing stressors, these impacts may, individually or cumulatively, affect people's ability to live in safety and with dignity’. ⁹

Nearly a third of States’ written submissions to the ICJ – plus many civil society submissions – raised displacement in the context of climate change as a key human rights concern. Some provided concrete examples of how displacement affects the realization of fundamental human rights. ¹⁰ For instance, Vanuatu described the extent of existing internal displacement and likely future movement within the country, observing that:

This forced displacement from ancestral lands and ecosystems leads to grave cultural losses. It impairs territorial sovereignty and inhibits the affected peoples from making a free choice about their futures. ¹¹

A number of submissions proposed that States whose wrongful acts had significantly contributed to climate change should provide reparations, including ‘non-monetary redress for the human mobility, including displacement and migration’ ¹² and compensation for ‘the cost of human mobility including displacement and migration’. ¹³

The ICJ Advisory Opinion: Some Key Issues

Non-refoulement in the Context of Climate Change

There is a long line of jurisprudence from national courts and international bodies, as well as a significant body of scholarship, explaining why States’ non-refoulement obligations under both international refugee law and international human rights law are relevant in situations where the adverse effects of climate change and disasters contribute to a real risk of persecution or other serious harm. ¹⁴ This is because the principle of non-refoulement applies to any context where a person faces a well-founded fear of being persecuted or a real risk to their life or of torture or other cruel, inhuman or degrading treatment or punishment. In other words, there are no special rules. As explained in the authoritative Practical Toolkit concerning international protection claims in the context of climate change and disasters:

International protection claims arising in the context of climate change and disasters should be assessed in the same way as all other protection claims – that is, through a systematic application of the applicable legal criteria to the established facts of the individual claim. ¹⁵

Even so, misunderstandings have led some decision-makers to assume that ‘disasters’ are natural and therefore cannot give rise to persecution, or that the impacts of climate change are indiscriminate and affect all people equally. This overlooks how climate change and disasters intersect with other social, economic and political drivers of displacement to form part of a broader ‘hazard-scape’, ¹⁶ as well as the differential impacts on particular individuals and communities (discussed further below).

As UNHCR explained in its legal guidance of 2020,

[t]he adverse effects of climate change and disasters are often exacerbated by other factors such as poor governance, undermining public order; scarce natural resources, fragile ecosystems, demographic changes, socio-economic inequality, xenophobia, and political and religious tensions, in some cases leading to violence. As a result of these negative impacts of climate change and disasters, combined with social vulnerabilities, people may be compelled to leave their country and seek international protection. ¹⁷

The ICJ's affirmation that States’ non-refoulement obligations apply in this context is therefore significant:

The Court considers that conditions resulting from climate change which are likely to endanger the lives of individuals may lead them to seek safety in another country or prevent them from returning to their own. In the view of the Court, States have obligations under the principle of non-refoulement where there are substantial grounds for believing that there is a real risk of irreparable harm to the right to life in breach of Article 6 of the ICCPR if individuals are returned to their country of origin (see Human Rights Committee, Teitiota v. New Zealand, 24 October 2019, UN doc. CCPR/C/127/D/2728/2016, para. 9.11). ¹⁸

In Teitiota v New Zealand, the UN Human Rights Committee had stated that:

The Committee is of the view that without robust national and international efforts, the effects of climate change in receiving states may expose individuals to a violation of their rights under articles 6 or 7 of the Covenant, thereby triggering the non-refoulement obligations of sending states. Furthermore, given that the risk of an entire country becoming submerged under water is such an extreme risk, the conditions of life in such a country may become incompatible with the right to life with dignity before the risk is realized. ¹⁹

Although the Committee's substantive analysis focused on article 6 of the ICCPR – the right to life – it recognized that the principle extended to article 7 as well. It is regrettable that the ICJ did not expressly endorse this. Even so, its silence should not be interpreted as a rejection of the point; rather, its discussion of Teitiota was in a section of the Advisory Opinion about the right to life, which likely explains its particular focus.

The court's reference to ‘conditions resulting from climate change which are likely to endanger the lives of individuals’ tacitly acknowledges that the impacts of climate change are felt within a wider political and social context. ²⁰ Systemic issues of discrimination or inequity impact on how particular people experience risk, even though they are often framed as individual attributes (such as age, gender or disability). Judge Charlesworth explained that ‘the adverse effects of climate change are not evenly distributed’, ²¹ and that ‘States have a particular obligation to protect the human rights of vulnerable groups. This requires close attention to the potentially discriminatory effects of measures taken to respond to climate change’. ²² She recalled, for instance, how ‘forced migration caused by climate change ha[d] led to the loss of Indigenous knowledge, rituals and customs’. ²³ Climate change also ‘reduces access to food, safe drinking water, sanitation, housing, healthcare, education and other goods and services that are essential for a life of dignity’. ²⁴

It would have been helpful for the ICJ to underscore this approach more emphatically. For instance, it could have drawnon the approach of the Inter-American Court of Human Rights which framed displacement squarely ‘as a response to structural and compounding risks, rather than isolated climate events’, ²⁵ and emphasized that ‘States must address both immediate triggers and the broader social, political, and environmental conditions that drive people to move in search of safety and dignity’. ²⁶ A cumulative assessment of risk is therefore crucial. ²⁷

The Inter-American Court went on to state that:

States must establish an appropriate regulatory framework that provides effective legal and/or administrative mechanisms at the domestic level to guarantee the legal and humanitarian protection of persons displaced across international borders due to the impacts of climate change. States must implement effective mechanisms to ensure humanitarian protection for these persons by establishing appropriate migration categories such as humanitarian visas, temporary residence permits, and/or protection under refugee status or similar status, which can provide them with protection against refoulement. ²⁸

In his separate opinion in the ICJ Advisory Opinion, Judge Aurescu lamented that the ICJ did not go further in its analysis. He thought that the court should have:

added that this obligation under international human rights law also includes positive obligations to take proactive measures to prevent refoulement and to ensure that other rights are respected during the individuals’ stay in the State's territory; such measures may cover, for example, a duty to conduct an individualized risk assessment, or an obligation to admit those seeking protection and even to issue temporary residence permits for them, to take appropriate protective measures against arbitrary detention and acts by non-State actors that may lead to refoulement. ²⁹

According to one commentator, ‘the ICJ missed an important opportunity to offer comprehensive legal guidance on how states must respond to displacement driven by climate change, not only in abstract but very concrete terms, especially for vulnerable populations’. ³⁰

The Right to a Healthy Environment

The court's limited explicit discussion of displacement in the context of climate change is not the end of the story, however. Another element of the ICJ's findings has considerable potential for future international protection claims: namely, the court's view that ‘a clean, healthy and sustainable environment is a precondition for the enjoyment of many human rights, such as the right to life, the right to health and the right to an adequate standard of living’. ³¹ This is a result of ‘the interdependence between human rights and the protection of the environment’. ³² If States are not safeguarding the environment, then ‘it is difficult to see how these obligations can be fulfilled’. ³³

Although the court did not discuss the content of this right, it did recognize ‘a close connection between the environment and the right to an adequate standard of living, which, for its part, encompasses access to food, water and housing, as set out in Article 11 of the ICESCR and Article 25 of the Universal Declaration of Human Rights’. ³⁴ This is helpful when it comes to understanding the kinds of ‘conditions resulting from climate change’ which could ‘endanger the lives of individuals’, ³⁵ especially when considered cumulatively. ³⁶

Further, in her separate opinion, Judge Charlesworth stated that the right to a clean and healthy environment has both substantive and procedural aspects, such as:

the right to a safe climate, clean air, a safe and sufficient supply of water, adequate sanitation, healthy and sustainably produced food … access to environmental information, participation in environmental decision-making, and access to effective remedies ... . ³⁷

According to the court, the right to a clean, healthy and sustainable environment also requires States to take measures ‘to preserve the environment and protect it against the adverse effects of climate change’. ³⁸ This is relevant in the international protection context when it comes to determining whether there are mitigating factors that could reduce or avert foreseeable risks, such that they would not reach the requisite threshold of harm to substantiate a refugee or complementary protection claim. As the Practical Toolkit explains, ‘government action to mitigate and reduce climate risks may indicate that international protection is not needed, where such action reduces the likelihood of harm to below the “real risk” threshold’. ³⁹

Conversely, if a State fails to take reasonable measures to protect people from known risks that threaten the right to life or expose people to inhuman or degrading treatment, a protection need will arise. ⁴⁰ As stated in the Practical Toolkit:

A failure by authorities to guard against known future climate risks could support a claim to international protection, at least in situations where risk reduction actions would not pose ‘[a]n impossible or disproportionate burden’ on the government. ⁴¹

It remains to be seen whether, and how, the right to a safe, healthy and sustainable environment is taken up in future international protection claims. Even though that right is not recognized as an independent ground for protection per se, its intersection with the right to life, and the right not to be subjected to inhuman or degrading treatment, provides a viable entry point.

The Duty to Cooperate

The court affirmed that the ‘duty to co-operate lies at the core of the Charter of the United Nations’. ⁴² It is also ‘a central obligation under the climate change treaties and other environmental treaties’, and customary international law reveals both a ‘duty of States to co-operate for the protection of the environment’ ⁴³ and ‘in the context of climate change’. ⁴⁴ While the court was not prescriptive about what such cooperation might look like, it includes cooperation on adaptation, loss and damage and capacity-building. ⁴⁵

In particular, the court acknowledged that sea-level rise ‘poses challenges in several respects, including of an economic, social, cultural and humanitarian character’, and found that ‘the duty to co-operate assumes particular significance in this context, requiring States to take, in co-operation with one another, appropriate measures to address the adverse effects of this serious phenomenon’. ⁴⁶ States must ‘work together’ to achieve ‘equitable solutions’, ⁴⁷ which would include meeting ‘obligations of adaptation and co-operation, including through technology and financial transfers’ under the Paris Agreement. ⁴⁸

In its oral submissions, Portugal had suggested that States have a duty to cooperate to address climate mobility:

Depending on the circumstances, States might have the duty to facilitate the cross-border movement of people or offer possibilities of temporary or permanent residence in their territory. Co-operation may also include the creation of bilateral or regional arrangements to manage migratory displacement patterns. It is also important to consider that, in certain circumstances, some effects of climate change, such as for instance sea-level rise, might make the return of persons to their place of original residence impractical or impossible. For this reason, co-operation should also include the co-ordination of efforts to find sustainable and durable solutions. ⁴⁹

Likewise, the Netherlands argued that ‘States have a duty to cooperate to ensure that such persons are accommodated elsewhere. This is a collective responsibility of the international community as a whole’. ⁵⁰

Unsurprisingly, given its limited consideration of displacement, the ICJ did not remark on any specific obligations States might have in this regard. However, it is certainly arguable that the general duties identified above could encompass obligations to assist people to stay in place through financial and technical assistance for adaptation and disaster risk reduction measures, and potentially even bilateral or regional mobility arrangements as a form of adaptation.

International cooperation can contribute to creating safer conditions through adaptation and disaster risk reduction, which, in turn, can mitigate or avert the risk of displacement. ⁵¹ Enabling people to remain in place was a component of a number of submissions. For instance, the Cook Islands stressed ‘the critical importance of honouring Cook Islanders’ aspirations to remain on their ancestral homelands for their health and wellbeing’. ⁵² It cited an expert report by Professor Yvonne Te Ruki Rangi a Tangaroa Underhill-Sem and Dr Christina Newport that stated: ‘Contemplating the loss of belonging to one's place, to one's ancestral home is more than a loss of indigenous ties to land sea and sky, it is a loss of deep belonging to one's generations past, present and future’. ⁵³

Tuvalu similarly stressed that its priority was to ensure its citizens could remain at home. ‘If Tuvaluans were to be displaced’, the submission explained,

they would suffer a loss of place, property, identity, culture, way of life, traditions, and more represented by fenua, particularly as Tuvaluans’ unique culture and traditions require maintaining the intimate connection with their land. ⁵⁴

The 2023 Falepili Union between Australia and Tuvalu, ⁵⁵ which has been much publicized because of the special human mobility pathway it creates for permanent migration to Australia, ⁵⁶ in fact ‘first and foremost’ commits both States to ‘work together to help the citizens of Tuvalu to stay in their homes with safety and dignity’. ⁵⁷

Even though the ICJ did not directly address States’ obligations specifically in this context, its general findings about States’ obligations to cooperate on ‘adaptation to the impacts of climate change’ are highly relevant. ⁵⁸ Furthermore, in affirming States’ fundamental duty to cooperate, the court recognized its ‘particular significance’ in the context of sea-level rise. Although the court did not explain precisely what this entails, it could conceivably extend to addressing climate mobility and providing safe and durable pathways for movement – as some States had argued.

Continuity of Statehood

A final aspect of the ICJ Advisory Opinion which is tangentially relevant to displacement is the court's affirmation that even if a State loses its territory and/or population on account of sea-level rise, ‘the disappearance of one of its constituent elements would not necessarily entail the loss of its statehood’. ⁵⁹ This accords with a line of recent authority from the International Law Commission (ILC), the International Law Association and States in the UN Sixth Committee, ⁶⁰ suggesting that statehood is likely to persist for some time, if not indefinitely. ⁶¹ Importantly, the ILC's summary of States’ deliberations in the UN Sixth Committee revealed that no State argued that statehood would be lost in such a scenario, ⁶² although some States regarded the matter as too inchoate at the present time. ⁶³

Pacific States have sought to crystallize the principle of continuity of statehood in the 2023 Pacific Declaration on the Continuity of Statehood and the Protection of Persons in the Face of Climate Change-Related Sea-Level Rise. They declared that ‘international law supports a presumption of continuity of statehood and does not contemplate its demise in the context of climate change-related sea-level rise’, and that ‘the statehood and sovereignty of Members of the Pacific Islands Forum will continue, and the rights and duties inherent thereto will be maintained, notwithstanding the impact of climate change-related sea-level rise’. ⁶⁴ In the Falepili Union between Australia and Tuvalu, the two States recognize that ‘the statehood and sovereignty of Tuvalu will continue, and the rights and duties inherent thereto will be maintained, notwithstanding the impact of climate change-related sea-level rise’. ⁶⁵

The relevance of this to displacement is indirect, but critical to note. There is a common yet misplaced notion that people will be rendered stateless as a direct consequence of sea-level rise and loss of territory. It is premised on a literal, rather than juridical, interpretation of statelessness. As a matter of law, an individual is stateless if they are ‘not considered as a national by any State under the operation of its law’. ⁶⁶ This concerns the existence, rather than the effectiveness, of nationality; it deliberately does not encompass de facto statelessness – that is, where an individual formally possesses a nationality but it is ineffective in practice.

Rather, the greatest risk of statelessness arising in the context of climate change is where ‘displacement breaks the connection between citizen and State’. ⁶⁷ For instance, some States

prevent or restrict children born to citizens overseas from acquiring their parents’ citizenship, restrict or prohibit dual citizenship, or withdraw a person's nationality if they reside abroad for a period of time, acquire another citizenship, or behave in the manner of a foreign citizen (by voting in a foreign election, or serving in a foreign army, for example). ⁶⁸

Thus, statelessness is unlikely to arise as a consequence of physical loss of territory but instead from the operation of States’ own nationality laws when people are displaced or otherwise move abroad. ⁶⁹

Conclusion

While the ICJ's direct findings on displacement are limited, the court has nevertheless drawn some clear lines in the sand and opened up new avenues for legal development. It affirmed the applicability of the principle of non-refoulement in the context of climate change, as well as continuity of statehood in the face of sea-level rise. The court's emphasis on the fundamental importance of human rights law as a source of States’ obligations with respect to climate change, along with its finding that ‘under international law, the human right to a clean, healthy and sustainable environment is essential for the enjoyment of other human rights’, ⁷⁰ provide important hooks for future international protection claims.

At the same time, the court candidly acknowledged the limits of international law in addressing climate change – ‘an existential problem of planetary proportions that imperils all forms of life and the very health of our planet’. ⁷¹ The ICJ explained that ‘a lasting and satisfactory solution requires human will and wisdom – at the individual, social and political levels – to change our habits, comforts and current way of life in order to secure a future for ourselves and those who are yet to come’. ⁷² International law alone is not up to the task.

In his separate opinion, Judge Yusuf went much further, expressing his ‘disappointment’ that the court adopted an ‘excessively formalistic approach’ ⁷³ and suggesting that the court ‘missed a historic opportunity to clarify … in a clear and tangible manner’, the legal consequences of States’ failure ‘to take appropriate action to protect the climate system from [GHG] emissions’. ⁷⁴ This was especially so given the severe impacts on small island developing States and the least developed countries. He also stressed that ‘climate change is a matter of cumulative nature over time’, and that our understanding will necessarily evolve as science develops. For that reason, he said, ‘it is crucial to leave the door open rather than closed on such a critical matter for the development of international law in response to climate change’. ⁷⁵

Indeed, States’ obligations with respect to climate-related displacement go well beyond non-refoulement alone. Adaptation and disaster risk reduction measures are crucial to try to avert displacement altogether, or at least to mitigate its impacts. Addressing climate mobility necessarily also demands holistic, multidisciplinary and multisectoral responses which can adapt to changing circumstances and needs over time. To be truly effective, they require international cooperation in good faith, as well as inclusive, participatory and collaborative approaches that reflect local and traditional knowledges and perspectives.