Summary:
On 16 June 2026, it was reported that the Constitutional Court of Costa Rica had ruled in a climate change-related amparo appeal concerning environmental impact assessments (EIAs) on climate-related impacts of development projects. The case, filed in 2024 by attorney and environmental law professor Mario Peña Chacón, aimed to compel government ministries to assess the climate risks and impacts of activities and construction projects subject to the EIA process.
The petition alleged a violation of the right of present and future generations (under the Costa Rican constitution and the Inter-American human rights system) to enjoy a safe climate as part of the right to a healthy and ecologically balanced environment, noting that the ministries had failed to issue guidance on EIAs concerning projects generating climate-related risks and impacts. It argued that these effects should be analyzed throughout the lifecycle of a project, from selection and siting, to planning and design, to implementation, closure, and decommissioning. To make this argument, the case cited Costa Rica’s obligations under international instruments such as the UNFCCC, the Paris Agreement, and the Central American Convention on Climate Change. It also drew on reports about Costa Rica’s vulnerabilities to extreme hydrometeorological events (hurricanes and tropical storms) as well as on recent findings by the Inter-American Court of Human Rights, the International Court of Justice, and the International Tribunal for the Law of the Sea, as well as the Constitutional Chamber’s own case-law regarding a healthy environment, EIAs, the prevention of environmental damage, and climate change.
In its ruling, the Chamber ordered the two ministries to coordinate their efforts to incorporate to examine the climate risks and impacts of activities and projects falling under the domestic regulatory framework governing EIAs (the 2022 Regulation on Environmental Assessment, Control, and Monitoring). In doing so, it set an 18-month time limit within which the Ministry of Environment and Energy (MINAE) and the National Technical Secretariat for the Environment (SETENA) are required to incorporate the assessment of climate risks and impacts into environmental impact assessment (EIA) procedures. In addition, the order requires project developers to implement climate mitigation and adaptation measures. The Constitutional Chamber also warned the respondent authorities that failure to comply with the order may result in criminal liability under Article 71 of the Law on Constitutional Jurisdiction. The state was also ordered to pay costs, damages and expenses.
There were several third-party interventions in this case, including from the UN Special Rapporteur on the human right to a healthy environment, Astrid Puentes Riaño, as well as the NGOs AIDA, World’s Youth for Climate Justice, Justicia para la Naturaleza, the Fidélitas University Legal Clinic on Climate Change, Interculturality, Environment, and Human Rights, Pro Natura, and APREFLOFAS, as well as from academics: Álvaro Sagot Rodríguez, Allan Astorga Gatgens, and David Anderson Lambert.
Suggested citation:
Constitutional Court of Costa Rica, Citizen (Mario Peña Chacón) vs. Costa Rica, ruling 2026-022147, June 16 2026.