In a landmark advisory opinion on July 23, 2025, the International Court of Justice (ICJ) delivered a transformative analysis of state obligations on climate change. For the nations of Africa; a continent that has contributed the least to historical emissions yet suffers disproportionately from its impacts. This ruling is not merely a legal milestone; it is a powerful new tool in the fight for climate justice. By establishing a definitive link between environmental protection and human rights, and with a significant focus on the impacts of sea-level rise, the Court has given legal weight to the crises already unfolding across the continent. This opinion reshapes the landscape of international law, articulating a clear framework for state responsibility that African nations can now leverage to demand accountability and action on a global scale.
The Human Rights Dimensions of a Changing Climate
The ICJ unequivocally recognized the profound and damaging effects of climate change on the enjoyment of fundamental human rights. The Court’s analysis affirmed that a clean, healthy, and sustainable environment is not merely beneficial but is a prerequisite for the fulfillment of a wide spectrum of human rights. This establishes an intrinsic link where states cannot meet their existing human rights commitments without concurrently protecting the environment. The Court explicitly stated that “the protection of the environment is a precondition for the enjoyment of human rights” (Paragraph 373). This interdependence, first recognized in the 1972 Stockholm Declaration (Paragraph 144), is foundational. The Court underscored this by noting that “the effective enjoyment of a number of human rights cannot be fully realized if those who hold them are unable to live in a clean, healthy and sustainable environment” (Paragraph 389) and that “the full enjoyment of human rights cannot be ensured without the protection of the climate system and other parts of the environment” (Paragraph 403).
The advisory opinion detailed how the adverse effects of climate change such as rising sea levels, prolonged droughts, and extreme weather events, directly impair fundamental human rights (Paragraph 376). The Court identified specific rights at risk, including the right to life (Paragraphs 377-378), health (Paragraph 379), an adequate standard of living encompassing food, water, and housing (Paragraph 380), and privacy and family life (Paragraph 381). For instance, the Court asserted that the respect and fulfillment of the right to life may depend on measures taken by states to preserve the environment (Paragraph 377). It also highlighted the disproportionate impact of climate change on the rights of vulnerable populations, including women, children, and indigenous peoples (Paragraphs 382, 384).
A significant outcome of this opinion is the Court’s recognition of the right to a clean, healthy, and sustainable environment as a human right in itself. The Court clarified that this right “results from the interdependence between human rights and the protection of the environment” and is “inherent in the enjoyment of other human rights” (Paragraph 393). Consequently, states are bound by international human rights law to respect, protect, and ensure the effective enjoyment of these rights by taking necessary actions to protect the climate system (Paragraph 403). This obligation, which states must consider when taking action on climate change (Paragraph 144), requires the adoption of both mitigation and adaptation measures and includes the regulation of private actors to prevent climate harm. This duty was formalized in the Court’s operative clause, which states that “States have obligations under international human rights law to respect and ensure the effective enjoyment of human rights by taking necessary measures to protect the climate system and other parts of the environment” (Paragraph 457 (3) E).
Sea-Level Rise: A Direct Threat to Human Rights and Self-Determination
The Court drew a direct and unambiguous line between the phenomenon of sea-level rise and its severe human rights consequences. It explicitly identified sea-level rise as a specific driver of human rights violations, stating that “the adverse effects of climate change, including, inter alia, the impact on the health and livelihoods of individuals through events such as sea level rise… may significantly impair the enjoyment of certain human rights” (Paragraph 376).
Furthermore, the ICJ linked the consequences of rising sea levels, such as forced displacement and the potential loss of state territory, to the fundamental right of self-determination. The Court observed that for small island states and low-lying coastal nations, these effects could be catastrophic, potentially leading to forced displacement and affecting their territorial integrity. In the Court’s view, because these threats are so closely connected to the existence of a people and their ability to govern themselves, “sea level rise is not without consequences for the exercise of this right” (Paragraph 357). This connection obligates states to cooperate to find equitable solutions. As the Court concluded, this legal obligation “requires States, in the context of sea level rise, to work together with a view to achieving equitable solutions, taking into account the rights of affected States and those of their populations” (Paragraph 365).
A Unified Standard of Due Diligence and State Obligation
A crucial element of the ICJ’s reasoning is its emphasis on the standard of “due diligence” as the primary measure of state conduct. This flexible standard is applied across different fields of international law, creating a unified framework for state responsibility in the context of climate change.
Under the UN Convention on the Law of the Sea (UNCLOS), states are obligated to take all necessary measures and use the “best practicable means” to prevent marine pollution (Paragraphs 345-347); a standard the Court described as a “stringent” form of due diligence (Paragraph 343). Simultaneously, under international human rights law, states must take “necessary measures” to protect individuals from foreseeable climate-related harm, which is also an obligation of due diligence (Paragraph 403). The Court’s analysis masterfully demonstrates that these are not separate duties but rather two facets of the same standard of conduct. A state failing to exercise stringent due diligence to prevent greenhouse gas emissions from harming the marine environment is concurrently failing in its duty to protect its people from the foreseeable human rights harms of climate change.
This logic reframes traditional state-centric obligations. The duty under UNCLOS to “protect and preserve the marine environment” (Article 192) is no longer merely an obligation owed to other states. Because the marine environment is essential for the life, health, and livelihood of people, protecting it becomes a necessary pathway for a state to fulfill its individual-centric human rights obligations. A failure to protect the sea is, by direct extension, a failure to protect the people who depend on it.
Similarly, the Court transformed the duty to cooperate. While UNCLOS frames this as a state-to-state procedural obligation, the ICJ’s analysis of sea-level rise infused it with a substantive human rights purpose. By concluding that cooperation must aim for equitable solutions that consider “the rights of affected States and those of their populations” (Paragraph 365), the Court shifted the focus. States are now compelled to cooperate not just to maintain international order, but to actively protect the rights and well-being of people threatened by the climate crisis.
What it means for Africa
For Africa, the continent most vulnerable to the impacts of climate change despite contributing the least to historical emissions, the ICJ’s advisory opinion is a monumental victory. It provides a powerful legal tool to amplify the long-held African position on climate justice, which emphasizes historical responsibility and the principle of “common but differentiated responsibilities.” The Court’s unequivocal linking of climate change to human rights validates the lived realities of millions across the continent who already face devastating consequences. For instance, recurring droughts in the Horn of Africa and the Sahel are intensifying water scarcity and food insecurity, directly threatening the right to life, food, and water as outlined by the Court (Paragraphs 377, 380). This opinion transforms what was a moral and political argument into a legally cognizable one, empowering African nations to demand more ambitious climate action from major emitters, framed not just as policy but as a fundamental human rights obligation.
The Court’s pronouncements on “due diligence” and the duty to prevent transboundary harm offer African states a more solid foundation to hold industrialized nations accountable. The ICJ’s reasoning that a failure to mitigate greenhouse gas emissions constitutes a breach of the obligation to protect the environment and, by extension, human rights, is particularly salient. Consider the coastal erosion and saltwater intrusion devastating communities in West Africa, from Saint-Louis in Senegal to the megacity of Lagos, Nigeria. These are direct consequences of sea-level rise, a phenomenon the Court explicitly linked to human rights impairment (Paragraph 376). Armed with this opinion, African states can argue more forcefully in international forums that the lack of stringent emission cuts by developed countries is a direct violation of their due diligence obligations, causing foreseeable harm to the African people’s rights to housing, livelihood, and even self-determination as their lands are rendered uninhabitable (Paragraph 357).
Furthermore, the ICJ’s emphasis on the “duty to cooperate” to find “equitable solutions” for those affected by sea-level rise (Paragraph 365) provides a significant lever for Africa in climate finance negotiations. For years, African nations have argued that adaptation finance is not charity but a matter of justice. The current flows of climate finance to Africa are a fraction of what is needed to adapt to the escalating impacts. This opinion reframes the narrative. The “equitable solutions” the Court speaks of can be interpreted to mean that providing finance for adaptation such as building sea walls in the Nile Delta, developing drought-resistant crops in Southern Africa, or supporting managed retreat for coastal communities, is not merely a political concession but a legal necessity to remedy a human rights crisis. It strengthens the call for a significant scaling-up of grant-based, easily accessible finance to help African nations protect their populations, thereby fulfilling the human rights obligations now clearly articulated by the world’s highest court.
By Swaleh H. Wengo
The author is a Law Lecturer at Prince Sultan University and a PhD Candidate at the University of Cape Town. This analysis is drawn from his ongoing doctoral research which examines the legal frameworks governing climate change in relation to the marine environment.
Excellent development. Hopefully African leaders will explore this legal development to their advantages