Exercising Planetary Jurisdiction: On the Legality and Legitimacy of Unilaterally Mitigating Planetary Ecological Footprints

Abstract International environmental law is increasingly depicted as being insufficient to prevent intertwined ‘planetary crises’ – notably, climate change and the advent of a sixth mass extinction of species. Perceived shortcomings in multilateral environmental treaties and their implementation have prompted policy-makers, particularly within the European Union, to rely more heavily on unilateral regulatory instruments aimed at addressing planetary crises beyond national borders. Examples include the Carbon Border Adjustment Mechanism, legal corporate sustainability due diligence instruments and import restrictions on products linked to deforestation. The exercise of jurisdiction to tackle planetary crises – referred to here as planetary jurisdiction – raises urgent concerns regarding the legality and legitimacy of unilateral regulation with extraterritorial reach. For some, such unilateral regulation is much needed and responds to a moral responsibility or even legal obligation; for others, exercising planetary jurisdiction is tantamount to ‘regulatory imperialism’. In this complex normative landscape, this article provides a nuanced perspective. Based on scientific insights, it highlights that the effects of planetary crises on the population of regulating states strengthen arguments for the permissibility of exercising planetary jurisdiction under customary international law and even support a human rights obligation for states to address their planetary footprint. Such an obligation, however, can be exercised in various ways, many of which would better align with considerations of equity and justice along North-South lines than existing forms of exercising planetary jurisdiction. Drawing from international environmental law, international trade law and human rights law, this article analyses the extent to which regulators face legal requirements to better address participatory and distributional concerns discussed under the heading of planetary justice.