Peremptory norms of general International Law (Jus Cogens) and the obligation to mitigate climate change : assessing the prospects for the emergence of a Jus Cogens obligation to mitigate climate change

Abstract

This study examines the evolving relationship between jus cogens norms and the international obligation to mitigate climate change. Jus cogens norms are defined as peremptory norms of general international law “accepted and recognized by the international community of States as a whole as norms from which no derogation is permitted, and which can be modified only by a subsequent norm of general international law having the same character.” In essence, jus cogens norms represent the most fundamental and hierarchically superior rules of the international legal order. Their non-derogable nature renders them universally binding on all States, irrespective of consent, thereby reflecting and protecting the most fundamental values of the international community.Against this backdrop, the study investigates whether the obligation for States to reduce greenhouse gas emissions has attained, or may in the future attain, a jus cogens status under international law. The inquiry was grounded on the increasing recognition among States that climate change is an “existential threat to humanity,” with consequences severe enough to endanger the continued survival of humankind. Applying an established criteria for the identification of jus cogens norms, the study systematically assessed the legal foundations, scope, and normative character of States’ mitigation obligations as reflected in treaty and customary international law.The findings demonstrate that States are legally bound, both through treaty-based obligations and customary international law, to take measures to mitigate climate change. However, the study concludes that while these obligations have not yet attained a jus cogens status, the study argues that the universal threat posed by climate change and the moral imperative to prevent catastrophic harm strongly support the gradual elevation of this obligation to a peremptory norm of general international law (jus cogens).