Description
In international legal scholarship and case law around the world, the legal argument is gaining ground that state responsibility can be established for adverse effects of climate change on human rights. However, a cloud of opaqueness surrounds the question as to the specific content of states’ obligations, e.g. when it comes to identifying the mitigation level required of a state for it to comply with its human rights obligations. In arguing that state obligations in the climate context are in fact not a nebulous gestalt, this paper investigates the potential of Integrated Assessment Models (IAMs) for devising a methodology of legal interpretation that allows to navigate the law-science-policy nexus in a systematic and transparent manner. Forming a key basis for most equity assessments of states’ climate action, IAMs not only translate greenhouse gas emissions into atmospheric concentrations and global mean temperature change but they also model socioeconomic behaviour. While the latter is a key determinant for emission pathways, predicting human choices inevitably introduces an element of (un)certainty to IAMs’ results. Opposing the view that this, however, a priori disqualifies IAMs for use in the legal context, this paper closely examines IAMs’ methodology through a legal lens. The paper engages in a detailed analysis of how the degree of scientific certainty in IAMs’ results aligns with legal concepts of risk and uncertainty such as the precautionary principle as well as with questions of admissibility and the standard of proof before international human rights courts. The analysis concludes that, while minute awareness of IAMs’ limitations and assumptions is critical, IAMs represent an invaluable and unignorable source of evidence for on operationalization of states’ human rights obligations vis-à-vis climate change that is compliant with best available science.
