Best available science, reasonableness, and environmental public decision-making

a dialogue between the Inter-American Human Rights System and Costa Rican constitutional jurisprudence

Abstract

This article analyzes the State obligation to use the best available science in environmental decision-making, based on the dialogue between international human rights law and Costa Rican constitutional jurisprudence. At the Inter-American level, it examines its connection with the right to a healthy environment, progressive development, and the right to enjoy the benefits of scientific progress, including the recognition of local, traditional, and Indigenous knowledge as an autonomous component of that right and as an indispensable element for climate decision-making grounded in the best available knowledge. At the domestic level, it studies the jurisprudential evolution of Costa Rica’s Constitutional Chamber, which has consolidated the principle of objectification of environmental protection, requiring public decisions with environmental impact to be supported by prior, sufficient, and verifiable scientific and technical criteria. The article argues that, although Costa Rican jurisprudence does not expressly recognize the right to science as an autonomous category, the requirement to rely on the best available science functions as a constitutional parameter that conditions the validity of State acts in environmental matters. It further concludes that this situation is undergoing an active process of transformation, based on the systematic reception of Advisory Opinion OC-32/25 by the Constitutional Chamber in a series of recent decisions, which anticipates the recognition of the right to science as an autonomous category through jurisprudence.