Symposium on Advisory Opinion AO-32/25 on the Climate Emergency and Human Rights: Not Only Humans, Not Only the Present – The Leap Toward Intergenerational Justice

[Ignacio Vásquez Torreblanca is the Executive Director of the Centre for Law and Climate Change Studies at the University of Valparaíso, Chile, a Research Assistant at the Max Planck Institute, Germany and a Research Fellow at the University of Manchester, UK]

Latin America is one of the regions most vulnerable to the effects of climate change, but it is also a laboratory for legal innovation. Advisory Opinion 32/25 of the Inter-American Court of Human Rights (IACHR) confirms this dual status, responding to the global climate emergency while also setting regional standards that could transform international law. The recognition of the right to a healthy climate and intergenerational equity as a legal principle places the Inter-American System at the forefront of the climate debate.

This post argues that AO-32/25 introduces an operational concept of intergenerational justice that reconfigures the architecture of the Inter-American System. Unlike previous pronouncements, such as Advisory Opinion 23/17 on Environment and Human Rights or landmark cases such as Pueblos Rama and Kriol v. Nicaragua and La Oroya v. Peru, the Court not only expands the catalog of environmental rights, but also affirms that state obligations must be extended even more profoundly to those who are not yet born. In this way, the Opinion provides concrete regulatory tools—such as non-regression, progressivity, and equitable distribution of burdens—that enable States to address cumulative and long-term environmental threats.

The innovation of the ruling, in line with the aim of this post, is manifested in three fundamental changes: (i) the structuring of intergenerational equity as a central normative criterion, consolidating its conceptual transition from an abstract principle to an operational legal parameter; (ii) the recognition of the right to a healthy climate as an autonomous fundamental right (paras. 298-316), anchored in the idea of humanity as a “moral and legal community that endures over time” (para. 311); and (iii) ecocentric change, which introduces nature as a subject of rights and opens a debate on its scope and tensions with the predominantly anthropocentric approach of international human rights law.

The Conceptual Transition from the Principle of Intergenerational Equity to the Advisory Opinion AO-32/25

The principle of intergenerational equity was established in international law thanks to the pioneering work of Edith Brown Weiss. In The Planetary Trust: Conservation and Intergenerational Equity, Weiss defined it as the obligation of the current generation to pass on to future generations a natural and cultural heritage in conditions no worse than those it received. According to this view, each generation acts as a temporary trustee: not as an absolute owner, but as a guardian of options that must be preserved for generations to come.

Based on this formulation, intergenerational equity moved from the theoretical to the normative level. Declarations such as Stockholm, Brundtland, and Rio, as well as sectoral treaties, such as the Joint Convention on Nuclear Safety, expressly incorporated the idea of avoiding disproportionate impacts on future generations. This expansion made intergenerational equity a cross-cutting principle of international law.

The judicial sphere reinforced this evolution. In its 1996 Advisory Opinion on the Legality of the Threat or Use of Nuclear Weapons, the International Court of Justice (ICJ) took an initial step by acknowledging that “the environment is not an abstraction but represents the living space, the quality of life and the very health of human beings, including generations unborn” (para. 29). Although the Court did not yet articulate intergenerational equity as a formal principle, this recognition was groundbreaking: it marked the first time the ICJ explicitly linked environmental protection to the rights and interests of future generations. More recently, in its 2025 Advisory Opinion on Climate Change, it defined intergenerational equity as the responsibility to preserve and pass on the conditions for a dignified life to those who do not yet exist, providing explicit evidence of the recognition of this principle (para. 156). Comparative jurisprudence has not remained on the sidelines; cases such as Neubauer v. Germany further developed this reasoning by introducing the notion of “intergenerational proportionality” to assess the deferred effects of climate inaction.

The Inter-American System has also advanced in this direction. In AO-23/17, the Inter-American Court conveyed a clear message when it included the right to a healthy environment for future generations. In La Oroya v. Peru, the Inter-American Court sought to directly protect essential resources such as air and water for those yet unborn. In AO-32/25, the Court expressed various innovative ways of consolidating the principle, establishing that States must preserve a climate free from dangerous anthropogenic interference (para. 300). Furthermore, it recognized the autonomous right to a healthy climate, projected toward present and future generations and toward nature itself, under the concept of humanity as a “moral and legal community that endures over time” (para. 311).

In summary, from Brown Weiss´s theory to its reception in international instruments and comparative jurisprudence, intergenerational equity has undergone a remarkable transformation. That is, in some contexts, it functions as an operational principle of international law; in others, as a criterion of interpretation; and, at the same time, it has become the basis for state obligations with erga omnes projection.

The Right to a Healthy Climate: The Key to Intergenerational Equity in AO-32/25

AO-32/25 not only identifies the right to a healthy climate as a substantive element of the right to a healthy environment, but also elevates it to a legal bridge for implementing intergenerational equity. The DER functions as a comprehensive framework that protects the essential elements of the environment—air, water, biodiversity, soil, ecosystems, and climate—through substantive and procedural components, with a focus on present and future generations. The right to a healthy environment, in turn, operates according to the Court’s reasoning as a specialized and operationalizable element, focused exclusively on ensuring the stability of the climate system free from dangerous anthropogenic interference, an enabling condition for the realization of all other human rights.

Building on this distinction, the Court places intergenerational equity at the core of the right to a healthy climate, drawing on precedents such as the decision that warned that delaying climate action shifts “disproportionate burdens” onto future generations. From this foundation, the Court affirms that protecting the environmental systems—including the climate—is a necessary duty to secure planetary habitability and, therefore, the effectiveness of human rights (paras. 287, 290, 293, 298). In this context, the notion of habitability is tied to the idea of a “common ecosystem.” In my view, the Advisory Opinion develops this idea along two central dimensions of habitability and intergenerational equity.

First, the Court understands that intergenerational equity transcends the strictly environmental sphere (para. 308), recognizing it as a cross-cutting principle that guides State action in the face of threats with cumulative and long-term effects. This gives rise to the need to implement a set of norms designed to guarantee the survival of present and future generations on a habitable planet. Among these tools, the Court highlights the established principles of international environmental law, emphasizing that intergenerational equity has emerged precisely as a response to the long-term impacts of climate change, pollution, and biodiversity loss (para. 287).

Second, the Court consolidates the autonomous nature of the right to a healthy climate by clarifying that its purpose is to ensure the continuity of humanity as a “moral and legal community that endures over time” (para. 311). On this basis, it warns that climate inaction disproportionately harms young people, who are forced to live their entire lives in a degraded environment (paras. 312-313)., The Court links this conclusion to intragenerational and intergenerational equity, emphasizing that both are essential for interpreting and fulfilling the obligations derived from the right to a healthy climate, since this right, in its collective dimension, seeks the comprehensive protection of humanity as a whole (para. 313). Moreover, the Court goes a step further by extending the effectiveness of the right to a healthy climate beyond the human sphere, projecting it also onto Nature, conceived as the physical and biological foundation of all forms of life (para. 315).

​​These dimensions, which connect generations and ecosystems, explain why the Court conceives the preservation of environmental balance as a jus cogens obligation, aimed at preventing irreversible harm and projecting the validity of all human rights into the future. On this basis, the operability of intergenerational equity within the right to a healthy climate unfolds in three phases: (i) non-regression and progressivity (para. 308); (ii) equitable distribution of burdens and benefits (para. 309); and (iii) procedural mechanisms that enable collective and youth-led actions. In this way, the right to a healthy climate emerges as a true axis of explicit intertemporality, transforming intergenerational equity from a programmatic principle into an operative and binding criterion, providing both future generations and Nature with a solid legal foundation to demand climate action.

Tension Between the Historic Progress of AO-32/25 and the Pending Limitations

Although AO-32/25 represents a historic advance in consolidating the right to a healthy climate as a cornerstone of intergenerational equity, its scope also reveals gaps and tensions that limit its effectiveness. A first limitation lies in the unresolved tension between anthropocentrism and ecocentrism (para. 283). By keeping human protection at the center, the Opinion risks reducing intergenerational equity to a purely human continuum, overlooking that the survival of future generations depends on safeguarding nature itself as a co-beneficiary. Without an ecocentric perspective, intergenerational equity cannot fully secure the ecological foundations on which future rights depend.

A second limitation concerns the shortcomings that can be seen in the intersectional approach. While the Court recognizes the need to identify new forms of vulnerability, it does not explore how gender, ethnicity, social class, or reproductive rights intersect with generational status to create differentiated risks. This omission weakens the intergenerational perspective, as the structural inequalities of the present are reproduced and magnified in the future, exposing certain groups of future generations to aggravated climate damage.

Finally, the transformative potential of AO-32/25 for intergenerational equity depends on its implementation at the national level. If states adopt fragmented legal frameworks or weak climate plans, future generations will inherit unequal levels of protection across the region. In this sense, the promise of intergenerational equity will only be realized if states establish consistent standards, allocate sufficient resources, and empower national courts to act as guarantors of a habitable planet for future generations. 

Conclusions

AO-32/25 crystallizes a process of legal maturation that had been developing for decades. The conceptual trajectory of intergenerational equity—from its theoretical formulation by Edith Brown Weiss to its reception in international instruments and comparative jurisprudence—finds a decisive turning point in this Advisory Opinion: intergenerational equity ceases to be an abstract principle and becomes an operational legal parameter with erga omnes projection. Its operational nature lies in the Court’s decision to elevate the right to a healthy climate as an explicit axis of intertemporality, thus transforming intergenerational equity from a programmatic aspiration into a binding criterion. To this end, the Court identifies specific phases of implementation—non-regression and progressivity, equitable distribution of burdens and benefits, and procedural mechanisms that allow for collective and youth-led actions—anchored in the jus cogens duty to preserve the habitability of the planet.

However, while AO-32/25 makes intergenerational equity a binding criterion and gives the right to a healthy climate a transformative scope, it also highlights significant limitations, such as the difficulty of consolidating genuine eco-centric change, the lack of clarity regarding its procedural legitimacy, and the failure to address an intersectional approach to vulnerability.

Combined with the challenges of its implementation at the national level, these tensions mean that its true impact will ultimately depend on the institutional and political capacity of states to translate this legal architecture into effective mechanisms for participation, redress, and protection in the face of the climate crisis.

Photo attribution: Photo by Noah Buscher on Unsplash