What does the ICJ’s advisory opinion on climate change mean for displaced people?

It has been a big summer for the field of climate change, migration, and international human rights. On 3 July, the Inter American Court of Human Rights released its historic advisory opinion on the legal obligations of states in light of the climate emergency, and on 23 July the International Court of Justice issued a landmark advisory opinion on the obligations of states in respect of climate change.

This article focuses on the basic implications of advisory opinion for climate im/mobility. In other words, for those who (will) move, in whole or in part due to climate factors, or for those who cannot move due to climate factors.

While the court did – groundbreakingly – touch on the concept of displacement and human rights, it did not go as far as the Inter American Court of Human Rights did on these issues.

Amidst the ample summaries, commentary, analysis, hope, and even doubt surrounding the ICJ’s opinion, one thing is clear: climate change is a real threat to us all, and states have an undeniable obligation to mitigate, adapt, and atone for the many ways in which that harm manifests.

Origins of the movement and key wins

Overall, the court rejected the oft-cited lex specialis argument used by many high-emitting states that are not signatories of various environmental and international treaties (such as the United Nations Framework Convention on Climate Change and the Paris Agreement). Namely, states argued that obligations should be limited to those arising under the treaties specifically addressing climate change, which would only apply to those who had signed them.

Instead, the court indicated that all states have a binding obligation to reduce emissions and harm, not only under those specific instruments, but also under international law, human rights law, the law of the sea, and other relevant instruments. The court also recognised that states and their populations who are harmed by climate change (which, it acknowledged, is human-caused) may be owed full reparations by high-emitting states under the principles of state responsibility.

The notion of climate reparations being underscored by the world’s highest court is of immense significance in the context of climate im/mobility, where typically the wants and needs of communities encompass the following (which are not mutually exclusive): the right to stay, the right to move, and the right to reparations to mitigate existing damage for as long as possible. Much of the latter is informed by and rooted in Indigenous advocacy, practices, and history.

It is therefore unsurprising yet deeply powerful that this opinion was the result of Indigenous, youth-led advocacy. Specifically, as a direct result of the tireless work of the Pacific Islands Students Fighting Climate Change (PSFCC). PSFCC was founded by law students from Pacific Island nations who were deeply concerned about the existential threat climate change poses to their homelands.

They began a grassroots campaign in 2019 calling for legal clarity on the obligations of states under international law to combat climate change, with a focus on securing an advisory opinion from the ICJ. The student group successfully gained the support of the government of Vanuatu, which then championed their cause on the international stage.

Through persistent lobbying, coalition-building with 130+ countries, and raising global awareness, PSFCC’s initiative culminated in a historic UN General Assembly resolution in March 2023. The resolution requested the ICJ to issue the advisory opinion on the obligations of states under international law to address climate change.

The court’s recognition of displacement

The court in its opinion took up many of the submissions made by the Solomon Islands regarding climate im/mobility.

Three paragraphs in particular are significant for our purposes.

357. Scientific data demonstrate 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. In the Court’s view, since these principles are closely connected with the right to self-determination, sea level rise is not without consequences for the exercise of this right.

Here, the court recognises both internal and cross-border displacement of populations due to sea level rise. It also considers the nexus between displacement of populations and the deeply existential and plausible risk of permanently losing the very place that they call home. The court’s recognition of these events, the rights of affected populations, and the validity of the supporting scientific evidence is profoundly consequential for future litigation in this field.

363. Several participants argued that sea level rise also poses a significant threat to the territorial integrity and thus to the very statehood of small island States. In their view, in the event of the complete loss of a State’s territory and the displacement of its population, a strong presumption in favour of continued statehood should apply. In the view of the Court, once a State is established, the disappearance of one of its constituent elements would not necessarily entail the loss of its statehood.

The opinion does not shy away from the inescapable probability that certain nations will physically cease to exist – a devastating thought. The court enshrines the protection of statehood for future inundated states, which nods to the imminent need to adapt and expand the notions of self-determination under international law, as well as the future of nationality and citizenship law within the context of the climate crisis.

The court goes on to say in the pursuant paragraphs [364-65] that “co-operation in addressing sea level rise is not a matter of choice for states but a legal obligation” and that in fulfilling this duty, states must “work together with a view to achieving equitable solutions, taking into account the rights of affected States and those of their populations”.

By framing cooperation as such, the court positions solidarity not just as a moral imperative, but as a legal standard. This could pave the way for more assertive legal claims and political demands for burden-sharing, technical assistance, and reparations, particularly from small island and low-lying states.

378. 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…Teitiota v. New Zealand, 24 October 2019, UN doc. CCPR/C/127/D/2728/2016…).

Perhaps most importantly, the court affirms in its opinion that it is natural for individuals exposed to life‑threatening risks from climate change to move.

As such, they may qualify for international protection, as refugees or under complementary protection, and the court explicitly states that the human rights principle of non-refoulement applies to people displaced across borders due to climate change. This directly affirms the Teitiota decision (summarised in the Climate Mobility Case Database), which in 2019 marked the first recognition by a human rights body that climate-induced displacement may engage non-refoulement obligations under international human rights law.

Moving forward

The ICJ opinion is likely already shaping the landscape of future climate litigation, international negotiations, and human rights frameworks. With the Inter-American and ICJ opinions now on record, the forthcoming advisory opinion from the African Court on Human and Peoples’ Rights (expected later this year) stands to complete a powerful trifecta of international judicial perspectives on climate change.

Together, these three opinions reflect a growing legal consensus: that climate inaction violates fundamental human rights. As more regions seek legal clarity on climate obligations, and as climate im/mobility becomes an increasingly central consideration, these opinions will serve as both legal anchors and political catalysts across treaties, Nationally Determined Contributions, and global grassroots campaigns.