Litigating the environment and climate change: public and private international law in tandem

Environmental harm, by its very nature, crosses territorial borders and legal orders. However, the responses to such harm remain fragmented between public and private domains, as well as between national jurisdictions and the international order. Against this backdrop, the present study examines the evolving intersection between public and private international law in protecting the environment and climate, and in regulating transnational corporate activities. The metaphor of the tandem is employed to argue that public and private international law should not be regarded as separate spheres, but rather as two complementary systems of law that must pedal in sync. The fundamental premise of this study is that there exists, within the framework of customary international law, an inherent right to access justice and that private international law is the means through which that duty takes effect in transnational settings. The analysis unfolds in three chapters. The first chapter sets the tandem in motion by mapping the multilevel legal architecture: the legal framework of environmental and climate protection at both international and domestic levels; the principal actors involved – States and corporations – and their respective obligations and responsibilities; the role of litigation at international, regional, and domestic levels. Through the comparative analysis of five selected legal systems (the United States, the European Union, Indonesia, Vietnam, and Nigeria), the second chapter examines the issue of adjudicatory jurisdiction, focusing on the conditions under which corporate defendants may be sued for cross-border harm. Finally, the third chapter addresses applicable law, assessing how conflict-of-laws techniques operate in environmental and climate disputes and how they might be recalibrated. The study concludes that access to justice is not a mere policy aspiration but a binding legal obligation incumbent upon States, and that the harmonisation of private international law is an indispensable condition for its effective realisation.