Enhanced Due Diligence

Advisory Opinion 32/25 (AO-32/25)  of the Inter-American Court of Human Rights (IACtHR) marks a turning point in the interpretation of international human rights law in relation to climate change. In AO-32/25, the IACtHR recognizes that the world is facing a genuine climate emergency and affirms that this situation demands an urgent, coordinated, and human rights-based response (see here and here).

The IACtHR establishes that States have a series of obligations to ensure a healthy environment and climate, and prevent violations of human rights. To this end, the IACtHR develops the standard of enhanced due diligence as a binding framework for State action. This standard includes elements aimed at ensuring that the response to climate change is effective, fair, transparent, and evidence-based (para. 224). The IACtHR explains that the severity of climate impacts, the urgency of effective action, and the need for accurate and up-to-date information require States to act with enhanced care to prevent harm and protect the rights enshrined in the American Convention. The specific shape this enhanced due diligence standard takes depends on particular risks, the degree of vulnerability of affected persons, and evolving scientific and technological knowledge (para. 233). This blog post discusses the heightened due diligence standard, as clarified by the IACtHR, and outlines nine key elements of this standard.

Comprehensive and in-depth identification and assessment of risks

The identification and assessment of climate-related risks forms the foundation of State obligations (para. 236). This makes sense; without knowing where the greatest threats lie and who is most affected, it is impossible to prevent harm or uphold rights. 

States must conduct comprehensive, detailed, and forward-looking assessments of how climate change impacts the effective enjoyment of human rights. As part of this assessment, States must consider both current and projected risks, using disaggregated data by territory, population group, gender, age, and other factors that shape vulnerability. A general or aggregate evaluation is not sufficient. What is required is a clear mapping of how specific individuals, communities, and ecosystems are affected, particularly those who have historically been marginalized or overlooked in public policy.

The IACtHR underscores the particular vulnerability of ecosystems such as the Amazon (para. 106), insular islands, and the Caribbean (paras. 111-119). These ecosystems are not only ecological hotspots but also cultural and spiritual homelands. Their loss would result in irreversible damage not only to biodiversity but to entire ways of life. These areas, along with others identified through the best available science, must be at the center of national strategies to ensure survival, adaptation, and justice. 

Risk assessment must also recognize that climate harm is not confined by borders. A State’s greenhouse gas (GHG) emissions can endanger rights and ecosystems far beyond its territory.  The obligation of comprehensive and in-depth identification and assessment of risk therefore applies not only to domestic policy but also to how States, especially major emitters, consider and mitigate the extraterritorial impacts of their actions or omissions, which was highlighted in KlimaSeniorinnen v Switzerland by the European Court of Human Rights and in Sacchi et al. v. Argentina et al.the Sacchi et al. v. Argentina et al. by the UN Committee on the Rights of the Child. 

Robust risk assessment is what enables timely early warning systems, targeted protection measures, and the meaningful participation of affected communities. It is the foundation for equitable climate governance and a test of whether States are serious about addressing the structural injustices that the climate crisis amplifies.

Adoption of proactive and ambitious preventive measures

States must adopt preventive measures to address climate-related harms that are proactive and ambitious, moving beyond mere compliance to transformative actions that prevent the worst scenarios projected by science. These measures should anticipate impacts, reflect the urgency of the climate crisis, and include reforming economic and social structures as necessary.

The IACtHR recalls that the Intergovernmental Panel on Climate Change (IPCC) has warned since 2018 that limiting warming to 1.5 or 2 degrees Celsius depends on significant emissions reductions this decade (para. 186). The IACtHR also reminds States of the pressing need to adopt effective mitigation and adaptation measures to prevent climate-related risks, not only through reductions in GHG emissions, but also by achieving “carbon neutrality” around the year 2050 (para. 186).  

This is particularly relevant in regions where, over the past decade, oil and gas exploration has continued to grow despite international climate commitments. According to the 2023 Global Oil and Gas Exit List, at least 96 companies are exploring new fossil fuel reserves in over 70 countries. In 2022 alone, projects were approved that will add 8.6 billion barrels of oil equivalent to future production. These projects would emit approximately 3.1 to 3.8 gigatons of carbon dioxide, based on standard emissions factors (≈0.43 tCO₂ per barrel for oil, adjusted for gas mix).  Meanwhile, the International Energy Agency reported that global investments in oil and gas exploration and production reached 528 billion dollars in 2023, a steady rise since 2020. These investments are expected to continue increasing, especially driven by state-owned companies in the Middle East, Africa, and Latin America. Such expansion directly contradicts scenarios aligned with the 1.5-degree goal of the Paris Agreement.

Use of the best available science

All climate action must be grounded in the best available science. This science must be up-to-date, peer-reviewed, empirically based, transparent in its methods, and clear about uncertainties and assumptions. The IACtHR explicitly names IPCC reports as authoritative. (para. 487)

The IACtHR makes clear that ignoring or manipulating scientific findings constitutes a violation of the duty of diligence. This could be interpreted to mean that denying climate science amounts to a human rights violation, as it undermines the evidence base needed to protect environmental and human rights. This point is particularly relevant in Latin America and the Caribbean, which are experiencing climate denial policies or efforts to weaken environmental protections (paras. 486-487).

Integration of a human rights perspective into all climate policy

The IACtHR demands that climate policies fully integrate a human rights-based approach. Measures must not generate new vulnerabilities or deepen existing ones. On the contrary, they must protect those at risk and ensure that the green transition does not reproduce existing inequalities (paras. 341, 342 and 388).

This approach was affirmed in previous IACtHR decisions. For example, in Lhaka Honhat v Argentina, the IACtHR recognized, based on Advisory Opinion 23/17 (AO-23/17), for the first time in a contentious case, the autonomous right to a healthy environment and other material conditions of existence concerning Indigenous peoples. The IACtHR emphasized that environmental degradation can violate collective and territorial rights, even in the absence of identifiable individual harm. This jurisprudence, in line with AO-32/25, strengthens the obligation to ensure that climate policies respect cultural identity, land rights, and the interconnectedness between ecosystems and community well-being across the region.

This is especially important in Latin America, the most unequal region in the world. According to the Economic Commission for Latin America and the Caribbean (ECLAC), in Latin America and the Caribbean, the richest 10 percent hold 55 percent of total income, while over 30 percent of the population lives in poverty. Gender and ethno-racial disparities further compound inequality. Integrating a human rights perspective supports a just transition, one that maximizes the social and economic benefits of climate action while safeguarding labor rights through effective social dialogue.

Continuous and effective monitoring of the outcomes and impacts of climate measures adopted

States must establish monitoring systems that are continuous, technical, independent, transparent, and participatory to oversee the implementation and effectiveness of climate mitigation and adaptation measures, the protection of ecosystems, the integrity of climate-related information and the performance of public and private actors. These mechanisms are not mere formalities; they are essential for evaluating the effectiveness of climate measures, detecting unintended harms, and adjusting strategies based on evolving risks and evidence (paras. 349, 354, 355, 366, 389).

Effective monitoring should enable real-time learning and correction, identifying implementation gaps, incorporating new scientific knowledge, and responding to the voices of affected communities. These systems should not be limited to state agencies but should also involve civil society, Indigenous peoples, and frontline populations (paras. 528, 560, 578, and 579).

Environmental impact assessments play a central role in this process. When properly designed, they help anticipate risks, evaluate alternatives, and ensure that environmental and social concerns shape decision-making. The IACtHR, notably especially in AO 23/17, already recognized EIAs as legal obligations tied to the duty of prevention It emphasized that they must be scientifically sound, transparent, and inclusive. In AO-32/25, the Court further strengthens this by linking assessments to participatory climate risk governance and adaptive measures. 

To fulfill this duty, national legislation must establish clear standards and mechanisms to act on findings. Political will is equally important. Laws have little impact without enforcement, oversight, and public access to data.

Respect for procedural rights: information, participation, and justice

The IACtHR’s jurisprudence has decisively advanced procedural rights. In Claude Reyes and Others v Chile, access to public information was recognized as an integral part of freedom of expression with direct environmental implications. The IACtHR reinforced the principle of maximum disclosure, under which all State-held information is presumed public unless excluded by narrow and justified exception. It also affirmed that due process guarantees apply to administrative procedures. Individuals are entitled to reasoned and timely responses when seeking information on activities that may affect their environment or health. States must adopt clear legal frameworks and effective mechanisms to ensure access to environmental information. This includes training officials, creating accessible registries, and enabling appeals of unjustified refusals. This ruling paved the way for many principles found in the Escazú Agreement and solidified access to information as a critical tool for environmental and human rights defense.

Building on this and other rulings, as well as other international treaties, in AO-32/25, the IACtHR confirms that access to information, participation, and justice are indispensable procedural rights in the context of the climate emergency (paras. 438, 459, 488, 495, 501). Information must be reliable and timely; participation must be meaningful, particularly in decisions affecting territories or ways of life; and effective remedies must be available for omissions or harms resulting from climate inaction (paras. 471-587).

Transparency and accountability

States must ensure full transparency and accountability in climate action. They must publish plans, goals, budgets, and indicators, and enable citizen oversight, independent audits, and parliamentary scrutiny (paras. 349, 355, 436, 438 and 505). 

The case of La Oroya v Peru illustrates the consequences of opacity, lack of transparency and accountability. The State failed for years to provide public access to environmental health data or act on evidence of severe pollution by a private metal smelting operation. In AO-32/25, the Court builds on these findings and reinforces that transparency is an indispensable condition and a legal obligation for ensuring accountability and preventing abuse (paras. 438, 505). It confirms that States must publish climate-related plans, indicators and budgets (para. 438), enable public oversight and independent audits (para. 505), and guarantee access to reliable, timely and culturally appropriate information (paras. 349, 436). Together, these standards establish that transparency is a concrete legal means to safeguard health, prevent environmental degradation and resist corporate impunity, principles central to both La Oroya and AO-32/25. 

Regulation and oversight of corporate due diligence

One of AO-32/25’s most powerful elements is its recognition that public and private businesses have responsibilities in the climate emergency, especially when their activities generate or significantly contribute to GHG emissions. This builds on the Court’s broader and longstanding jurisprudence that the obligation to guarantee rights extends beyond the actions of State agents and includes the duty to prevent violations by private actors. In a growing line of jurisprudence, the IACtHR has reaffirmed that States must regulate and oversee business activities to prevent rights violations, especially where Indigenous Peoples are affected. In Kaliña and Lokono Peoples v. Suriname, the Court found that granting concessions for logging and mining on Indigenous lands without consultation or safeguards violated the Convention. This finding was reinforced in Garífuna Communities of Triunfo de la Cruz and Punta Piedra v. Honduras, where the Court held the State responsible for failing to protect communities from violence and dispossession amid land conflicts involving third parties. Most recently, in La Oroya v. Peru, the Court held the State accountable for failing to regulate a private company whose toxic emissions severely harmed residents’ health and environment.

Following the same logic, the IACtHR establishes in AO-32/25  that States must enact legislative, regulatory, and administrative measures to ensure companies apply enhanced environmental and human rights due diligence. This means requiring internal due diligence processes adapted to a company’s size, sector, and context. These processes should span the entire value chain, including suppliers and subsidiaries, and aim to identify, prevent, mitigate, and remedy adverse impacts (paras. 345-456). The IACtHR further mandates that States assign differentiated obligations to higher-emitting companies, reflecting the principle that those who pollute more must bear greater responsibility. This could include higher taxes, stricter regulatory requirements, mandatory participation in just transition schemes, or specific investments in mitigation and adaptation (para. 350). 

The IACtHR also warns against greenwashing, undue corporate influence in lawmaking, and threats against human rights defenders by corporate actors. This business dimension of enhanced diligence has immediate relevance for litigation, regulation, and advocacy.

Reinforced international cooperation

Because climate change is global, States have a duty to cooperate. This includes technology transfer, climate financing, capacity building, shared knowledge, and collective responses to climate change (para. 264). While these obligations are already reflected in instruments such as the Paris Agreement, the IACtHR now lends them regional legal weight within the Inter-American human rights system. The IACtHR also affirms that international cooperation is essential to address the disproportionate impacts of climate change on countries and populations that have contributed least to the crisis (paras. 260–261). It links the duty to cooperate with the elimination of poverty, the promotion of sustainable development and the guarantee of economic, social and cultural rights. The IACtHR also highlights that this duty encompasses not only financial and technical support, but also the creation of fairer economic systems and sustained multilateral engagement grounded in solidarity (paras. 262–265). 

Conclusion

The IACtHR’s model of enhanced due diligence goes far beyond technical obligations. It redefines responsible climate action in a world of accelerating risks and deepening inequality. The IACtHR offers a structured and principled framework that guides States not only in responding to climate threats, but in how they plan decisions and govern with human dignity, justice, and environmental integrity at the center.

This framework moves due diligence from narrow project-based procedures to a broader standard of governance. It applies across legal systems, national boundaries, and policy sectors, recognizing that although climate change is a global phenomenon, its consequences are deeply unequal. It challenges States to move beyond symbolic commitments and take action that is transparent, science-based, and rooted in the lived experiences of those most affected.

The influence of the Inter-American system increasingly extends beyond the region. In Kenya, the Environment and Land Court just drew on the La Oroya case to reaffirm that the environment cannot protect itself and that it is the role of the State to safeguard it. This reasoning supported the Kenyan court’s decision to order the restoration of land and water harmed by pipeline construction. AO 23/17 has also helped shape global standards. Its principles have been echoed by the United Nations Committee on the Rights of the Child and cited by Brazil’s Supreme Federal Court in recognizing the Paris Agreement as a human rights treaty (see here). Together, these developments reflect a growing cross-regional judicial dialogue and demonstrate the importance of the Inter-American system in protecting the environment both within the region and globally. They also confirm that advisory opinions are not abstract texts but powerful legal tools that shape jurisprudence, inform public policy, and empower communities pursuing climate justice.

For lawyers, advocates, and institutions, the IACtHR’s framework is more than legal guidance. It is an invitation to reimagine environmental governance as a space for transformation, inclusion, and accountability. It affirms that truly effective climate action must be grounded in human rights and capable of transforming the systems that have allowed environmental harm and exclusion to persist.