The Role of the Amicus Curiae before the Inter-American Court of Human Rights

The Advisory Opinion on Climate Emergency and Human Rights issued by the Inter-American Court of Human Rights (IACtHR) on July 3, 2025, has been described as a historic event and a turning point in human rights-based climate litigation. The requested advisory opinion by the Republics of Colombia and Chile has attracted a total of 263 amicus curiae briefs – nearly as many as were submitted in the first 40 years of the Court’s functioning since 1979. In their consultation, the two requesting states ask the Court to clarify state obligations to respond to the climate emergency within the framework of international human rights law. This is a moment of unprecedented significance in the development of climate and human rights litigation and requires detailed analysis in order to understand the exponential rise in civil society and NGO (non-governmental organization) participation. Therefore, it is necessary to examine the historical background that led to the close relationship we observe today between the IACtHR and CSOs (civil society organizations), as well as the increasingly recognized nexus between human rights and the climate emergency. As explained by Pennino (forthcoming), NGOs present a subcategory of the broader concept CSOs, which encompasses a diverse range of actors and groups (Dupuy & Vierucci, 2008). Our team had the opportunity to submit an amicus curiae brief before the Inter-American Court in relation to the Advisory Opinion on Climate Emergency and Human Rights, and to intervene in person during the public hearings held in April 2024 in Bridgetown, Barbados. At the same time, we conducted semi-structured interviews with experts in human rights-based climate litigation who intervened before the Court and possess a significant amount of practical experience and technical expertise in this field. This paper seeks to examine the significance of amicus curiae participation before the Inter-American Court of Human Rights, while studying the underlying dynamics that have contributed to the notable increase in amicus curiae submissions in recent years, particularly in light of the Advisory Opinion OC-32/25 on Climate Emergency and Human Rights. The first part of this paper addresses the historical background of the amicus curiae and analyzes the multiple reasons for the recent rise in amici involvement. The second part examines the content and scope of the Advisory Opinion OC-32/25, while integrating outcomes from our interviews conducted in Barbados in the spring of 2025. The final section deals with the role of civil society actors in human rights-based climate litigation and to what extent strategic litigation is a useful instrument before courts in this domain. This paper constitutes a working paper, based on academic publications and legal documents, while recognizing the current limitations that exist, particularly regarding data and statistical assertions of amicus curiae submissions before the IACtHR.