Precaution as Obligation?

On March 14, 2025, the Inter-American Court of Human Rights (IACtHR) made public a landmark ruling holding Ecuador internationally responsible for the violation of various rights of the Tagaeri and Taromenane, the last remaining Indigenous peoples living in voluntary isolation (PIAV) in the western Ecuadorian Amazon (for an early commentary see here). This blog post explores how the judgment reaffirmed the IACtHR’s expansive approach to Indigenous rights and ventured into uncharted legal territory by treating the precautionary principle as a justiciable obligation rather than a mere interpretative aid. This bold move has significant implications for the intersection of environmental law and human rights, particularly in cases involving Indigenous communities whose survival hinges on territorial integrity, limitation of extractive activities, self-determination, and non-contact policies.

Context and Significance

The Tagaeri and Taromenane, Indigenous groups living in voluntary isolation in the Ecuadorian Amazon, have long been under threat from extractive industries, illegal logging, and territorial encroachment. Their survival depends on the integrity of their land and strict adherence to the principle of non-contact, which recognizes their right to remain isolated without interference. The Ecuadorian government has recognized this status by establishing the Zona Intangible Tagaeri-Taromenane (ZITT), a legally protected area meant to shield these communities from external pressures. However, despite these protections, oil exploration and extraction activities—particularly within the Yasuní National Park—have continued to encroach on their territories.

The IACtHR case arose from a series of violent incidents, including the massacre of several Tagaeri and Taromenane individuals in 2003, 2006, and 2013, events that highlighted the vulnerabilities of these Indigenous communities. The applicants argued that Ecuador had failed to implement adequate measures to prevent contact, ensure territorial integrity, and uphold its international obligations under the American Convention on Human Rights (paras. 174-177)

Apart from the bold interpretation of the precautionary principle that will be analyzed in the later section, the IACtHR addressed the complexity of consulting with people who have chosen to remain uncontacted. The IACtHR underscored the inextricable link between the Tagaeri and Taromenane’s territory and their survival as ecosystemic peoples, meaning they live in strict dependence on their ecological environment, from which they derive their livelihood, cosmologies, social institutions, customs, and their notion of good living (para.104). Therefore, their right to collective property, self-determination, and autonomy is contingent on preserving their land and strictly enforcing the principle of non-contact. The Court noted that respecting their free self-determination and their choice to remain isolated means that Indigenous peoples in voluntary isolation do not engage in conventional forms of participation (para. 184). Consequently, it becomes impossible to conduct free, prior and informed consultations according to the standards established by the Court regarding the determination of their territory and any development or investment projects that may impact them (para. 191). In this context, the duty to consult translates, for the PIAV, into an obligation for the State to consider the decision of these groups to maintain their isolation in any project or decision that may affect them. This includes incorporating the precautionary principle and ensuring that the measures adopted are proportional, considering their way of life and its potential impact (para. 193).

The Precautionary Principle and Indigenous Rights in the IACtHR’s Tagaeri and Taromenane v. Ecuador Ruling

In Tagaeri and Taromenane Indigenous Peoples in Voluntary Isolation v. Ecuador, the IACtHR broke new legal ground. At the heart of its reasoning was the application of the precautionary principle, which the Court interpreted not merely as a guiding norm but as a binding legal obligation. This shift could reshape how courts in the Global South—and beyond—understand states’ responsibilities when extractive industries intersect with human rights and environmental protection.

In paragraphs 225–227 of the ruling, the Court declared that due to the serious and potentially irreversible harms posed by oil operations in the Amazon, Ecuador was legally obligated to apply the precautionary principle as a corollary to the principle of non-contact. The latter is rooted in the rights to self-determination and consultation of Indigenous Peoples in Voluntary Isolation (PIAVs). The Court stated:

“Even in the absence of scientific certainty about the impact of oil exploration and exploitation projects on their territory, effective measures should be adopted to prevent serious or irreversible damage, which in this case would be the contact of these isolated populations.” (para. 226)

This statement is a significant departure from prior practice. The precautionary principle has traditionally served as a flexible, interpretative tool within international environmental law. However, the Court reimagines it as a justiciable right—a claimable legal standard that Ecuador had failed to uphold.

From Environmental Law to Human Rights Law

The precautionary principle originated in international environmental law as a response to scientific uncertainty. It gained prominence through Principle 15 of the 1992 Rio Declaration, which holds that a lack of full scientific certainty should not delay measures to prevent environmental degradation. The principle is further enshrined in treaties such as the UN Framework Convention on Climate Change and the Stockholm Convention on Persistent Organic Pollutants.

Over time, regional human rights bodies cautiously integrated this logic into their jurisprudence. In Tătar v. Romania (2009), the European Court of Human Rights (ECtHR) used the principle to evaluate Romania’s response to gold mining pollution. Likewise, in Cordella and Others v. Italy (2019), the ECtHR underscored the state’s duty to proactively address environmental risks. Although often not cited explicitly, precautionary reasoning has increasingly shaped ECtHR decisions concerning environmental and public health risks under Articles 2 and 8 of the ECHR (right to life and private/family life).

Most recently, in Cannavacciuolo and Others v. Italy, the ECtHR moved closer to embracing the principle explicitly. The Court affirmed that states must investigate and assess hazardous activities, reinforcing a due diligence obligation grounded in the right to life (para. 391).

A Bolder Move by the IACtHR

Unlike its European counterpart, the IACtHR in Tagaeri and Taromenane treated the precautionary principle not merely as a tool for lowering evidentiary thresholds but as a standalone legal duty. The Court held that Ecuador violated this obligation by declaring a national interest in oil development without considering confirmed sightings of PIAVs in the areas concerned. The Court emphasized that Ecuador failed to “adequately guarantee” the principle during both the declaration and implementation stages (para. 227).

This treatment of the principle as both a procedural safeguard and a substantive obligation suggests that the IACtHR is shaping a new norm through what may be described as hermeneutic expansion. The Court’s approach oscillates between invoking the principle to fill normative gaps and applying it directly as a source of state responsibility.

This is not the first time the IACtHR has elevated the status of the precautionary principle. In its Advisory Opinion OC-23/17 on Human Rights and the Environment, the Court stated that “in the context of the protection of the rights to life and personal integrity,” states must act in accordance with the precautionary principle when there are plausible risks of severe and irreversible environmental harm (para. 180).

In La Oroya v. Peru, the Court extended this logic to the right to health under Article 26 of the American Convention, asserting that scientific uncertainty does not justify state inaction in the face of environmental harm (para. 127). It also connected the precautionary principle with intergenerational equity, borrowing from Rio Principle 3 and other instruments (para. 128). This connection resurfaced in Pueblo U’wa v. Colombia (2024), albeit in passing (para. 295).

Judicial Innovation or Overreach?

The Court’s systemic integration of environmental norms into human rights law is a bold maneuver, particularly given the legal vacuum that often surrounds the rights of PIAVs. The late Judge Antônio Cançado Trinidade, a vocal advocate of expanding principles within international law, argued that the IACtHR often applies the precautionary principle as a means to reverse the burden of proof in cases of grave rights violations. This is especially relevant when states fail to disclose critical information.

Yet, not all judges agreed with this doctrinal innovation. In a partially dissenting opinion, Judge Sierra Porto criticized the Court’s reliance on non-binding instruments—specifically the Guidelines for the Protection of Indigenous Peoples in Isolation and Initial Contact. He warned that applying the precautionary principle to unexploited extractive areas risks setting a precedent for banning all activities in any zone where PIAVs might later be identified (para. 8 of his dissenting opinion).

Similarly, Judge Pérez Goldberg raised concerns about legal coherence. She argued that the precautionary principle had previously been applied only to rights such as life, integrity, and health—not to collective property or self-determination. In her view, the majority did not sufficiently explain this doctrinal leap. To an extent, this is a reasonable claim given that a jurisprudential explanation of the treatment and elasticity of the precautionary principle is not properly fleshed out.

Conclusion

The Tagaeri and Taromenane case is not merely a liberal tale of vulnerable people denied their rights. It is a stark example of the violent extraction dynamics that define the global periphery–core divide. Ecuador’s pursuit of nation-building through oil extractivism clashes with the ontological resistance of Indigenous communities, whose existence challenges dominant development models. Their radical way of existing undermines the assumptions of coloniality and modernity.  The violence they have endured—from missionaries to loggers, settlers, and the state—echoes colonial logics of accumulation through dehumanization.

In this fraught postcolonial context, what can courts offer? The IACtHR has turned to the justiciability of the precautionary principle, reinterpreting it through a human rights lens. This move reflects the Court’s broader strategy of adapting environmental law to address structural injustices, asserting legal imagination where political remedies remain elusive.