Together for Health: How the Inter-American Court Brings Science and Knowledge to the Climate Fight

In July 2025, the Inter-American Court of Human Rights (IACtHR) issued Advisory Opinion OC-32/25 on the climate emergency, one of the most comprehensive judicial pronouncements on climate change to date. Responding to a request from states in the region, the Court clarified how rights under the American Convention on Human Rights — including life, health, and a healthy environment — shape states’ obligations in addressing the climate crisis. It articulated duties concerning mitigation, adaptation, prevention of environmental harm, and protection of vulnerable populations.

Within this broader doctrinal landscape, this post focuses on a key contribution of the Opinion. Timed to coincide with World Health Day 2026 — ‘Together for Health: Stand with Science’ — it highlights how the Court gives legal expression to that call by grounding state obligations in science and local, traditional, and Indigenous knowledge.

The Opinion arrives at a turbulent moment, in which governments are increasingly challenging the authority of law. Yet OC-32/25 also reveals openings. These create space for a broader range of actors to strengthen health protection. Through transnational cooperation and strategic litigation, courts, researchers, civil society, and health institutions can stand together for stronger health responses to the climate crisis.

Climate Change, Health, and the Turn to Courts

Climate science leaves little room for doubt: Climate change harms human health. The Intergovernmental Panel on Climate Change concludes that climate change has already affected physical health globally and mental health across regions. The latest Lancet Countdown report further underscores the scale of the threat. Heat-related deaths have surged by 23 percent since the 1990s, and the global average transmission potential of dengue has increased by up to 49 percent since the 1950s. 

Indigenous peoples and local communities have also documented environmental change through lived observation and stewardship of land and ecosystems. For example, Arctic Inuit communities warned decades ago about thinning sea ice, shifting wildlife patterns, and growing risks to food security and mobility. 

Against this backdrop, states and the UN General Assembly asked three international courts to clarify states’ legal obligations regarding climate change in 2023. The International Tribunal for the Law of the Sea issued its advisory opinion in May 2024, the IACtHR in May 2025, and the International Court of Justice shortly thereafter.

Among them, the Inter-American Court made one of the most significant doctrinal contributions by anchoring public health-relevant climate obligations in the right to science and the recognition of local, traditional, and Indigenous knowledge.

The Inter-American Court: Placing Public Health at the Center of Climate Governance

The Court’s jurisdiction covers Latin America and the Caribbean, a region where the climate emergency is also a health crisis. While contributing only about 4 percent of cumulative global greenhouse emissions, the region remains deeply tied to extractive industries and expanding fossil-fuel frontiers.  At the same time, it is among the most vulnerable regions to climate impacts, aggravated by fragile health systems and further straining them. 

In defining the scope of state obligations on mitigation and adaptation under the American Convention of Human rights, OC-32/25 places public health at the center of climate governance.

• With respect to mitigation, the Court clarifies that States must set binding and progressively stronger emissions-reduction targets, regulate and supervise major emitters — both public and private, protect carbon sinks, and require climate-impact assessments. The logic is preventive: Unchecked emissions foreseeably intensify heat exposure, the spread of disease, malnutrition, and other threats to life, personal integrity, and health.

• The Court treats adaptation as a duty to prevent climate impacts on the right to health, including by strengthening the resilience of medical and health-care infrastructure to climate disasters, training health personnel to manage climate-related diseases — such as dengue and malaria — and expanding prevention through vaccination and public awareness.

Perhaps the most innovative feature of the Opinion lies in linking the right to science and the recognition of local, traditional, and Indigenous knowledge as a procedural and epistemic framework guiding these mitigation and adaptation obligations.

In practical terms, the Court clarifies that states must make reliable climate science accessible, support research and public participation, rely on the best available evidence in policymaking, and cooperate internationally. At the same time, they must recognize, protect, and integrate local, traditional, and Indigenous knowledge, particularly where it strengthens health systems and risk response. In doing so, the Opinion advances epistemic justice by addressing the long-standing marginalization of diverse knowledge systems in climate and health governance. 

Because protecting health depends on timely and accurate climate information, states must also use these knowledge sources to generate disaggregated data, operate effective early-warning systems, and counter climate-related disinformation.

Together for Health: Standing with Science and Local, Traditional, and Indigenous Knowledge

Yet a fundamental question remains: How are these obligations to be implemented where governments lack resources and where international law appear to have lost part of their persuasive force?

The Opinion offers two openings through which science and diverse knowledge systems can serve as a basis for standing together for health:

1. Transnational Cooperation. Partnerships among private actors, academic institutions, and Indigenous and local communities can sharpen understanding of where and how policy interventions should be directed. Initiatives such as the Special Programme for Research and Training in Tropical Diseases (TDR) and the InterAcademy Partnership (IAP) illustrate how transnational scientific cooperation has advanced public health responses to challenges affecting vulnerable regions. Comparable collaborations will be essential to confront the health risks associated with climate change.

• Strategic Litigation. Health concerns have appeared in climate litigation before, but often without remedies addressing the structural vulnerabilities of health systems. OC-32/25 opens the possibility for litigation to draw on science and diverse knowledge to challenge, for example, government inaction when climate-driven disease outbreaks overwhelm public health systems lacking adequate preparedness or vaccination strategies. 

Conclusion

Ultimately, the significance of OC-32/25 lies not only in the standards it articulates but also in the possibilities it opens for placing public health at the center of climate governance. At a moment when international cooperation and the authority of law appear fragile, the Opinion shows how science and diverse knowledge communities can still guide collective action — making World Health Day 2026’s ‘Together for Health: Stand With Science’ more than a slogan, but an invitation for a wide range of actors to help build the solidarity needed to safeguard health in a warming world.