Systemic Integration of Obligations in an Era of Climate Change: Stability and Optimal Control

Abstract Two systems might be said to govern the world: a system of public international law, and the climate system. Both systems endure in an epoch popularly described as the Anthropocene, during which drastic changes to the Earth’s atmosphere, land and oceans have been wrought by human activities. Amidst the existential challenges to both systems posed by these conditions, judges at the International Court of Justice (ICJ) and the International Tribunal for the Law of the Sea (ITLOS) have delivered advisory opinions about the obligations of States to protect the climate system. This review essay explores whether systemic integration of the norms of public international law, which comprises techniques of treaty interpretation and institutional practices, serves to protect the climate system. It does so by drawing on concepts in systems theory, before reviewing three works: Campbell McLachlan’s The Principle of Systemic Integration in International Law (OUP 2024), Andrea Bianchi’s and Fuad Zarbiyev’s Demystifying Treaty Interpretation (CUP 2024), and Oran R Young’s Addressing the Grand Challenges of Planetary Governance: The Future of the Global Political Order (CUP 2023). By situating the discussion of these works against the later climate change advisory proceedings, and in particular the questions from the bench during the public sittings at the ICJ, this review essay demonstrates the constraints, assumptions, and opportunities of systemic integration in an era of climate change. The Principle of Systemic Integration in International Law. By Campbell McLachlan KC, Oxford University Press, Oxford, 2024. LXIV + 453pp. £140 Demystifying Treaty Interpretation. By Andrea Bianchi and Fuad Zarbiyev, Cambridge University Press, Cambridge, 2024. XIV + 290pp. £25.99 Addressing the Grand Challenges of Planetary Governance. By Oran R Young, Cambridge University Press, Cambridge, 2023. V + 64pp. £17