Chapter 4 analyses the three selected challenges facing international tribunals – managing change, reviewing State conduct for compliance with international law, and dispute resolution – in the International Court of Justice (ICJ)’s environmental case law. The ICJ has repeatedly adapted aging treaty frameworks given relevant developments in international law and has also faced the problem of change in relevant facts. While the terminology of a standard of review is not firmly established in the ICJ’s case law, the underlying functional problem – concerning the intensity of an international tribunal’s scrutiny of determinations made by domestic authorities – is clearly present. Although three-step proportionality analysis is not entrenched in the ICJ’s case law, the Court has repeatedly used a reasonableness-based test that operates similarly to least restrictive means testing. Finally, the ICJ often adjudicates in a forward-looking, facilitative manner, seeking to assist the parties to manage their relationship after adjudication. Throughout, the chapter reflects on how the ICJ’s practices are shaped by its institutional features, such as its lack of any compulsory jurisdiction.

Chapter 3 analyses the three selected challenges facing international tribunals – managing change, reviewing State conduct for compliance with international law, and dispute resolution – in the environmental case law of the International Tribunal for the Law of the Sea (ITLOS) and arbitral tribunals constituted under the UN Convention on the Law of the Sea (UNCLOS). UNCLOS tribunals have often interpreted the Convention in a manner that takes account of relevant developments in international law. This is partly due to features of UNCLOS itself, including that it contains many generic or open-ended terms. The chapter demonstrates that the standard and method of review are significant issues in the environmental case law of UNCLOS tribunals, in the context of the Convention conferring on coastal States discretionary powers. These issues raise similar functional questions to those seen in the other adjudication contexts studied, for example regarding the rationales for some deference to domestic authorities. Finally, the chapter demonstrates that UNCLOS tribunals often adjudicate in a facilitative, forward-looking manner, aiming to assist the parties to rebuild their relationship.

Chapter 6 draws together and extends the comparative analysis that has unfolded across the prior chapters. It explains why tribunals’ practices differ across the regimes studied, focusing on contextual differences between the selected tribunals. It also assesses to what extent the practices of the selected tribunals provide insights into wider problems facing international adjudication and legal techniques that are potentially transferable across contexts. Structurally, the chapter discusses consecutively my findings in relation to the three challenges confronting international tribunals analysed throughout the book: managing changes in international law or relevant facts, calibrating the appropriate standard and method of review when scrutinising State conduct for compliance with international law, and contributing to broader processes of dispute resolution. The chapter finishes with some final remarks that close the book, concerning its contribution to our understanding of the role of international adjudication in contemporary international law and its implications for future studies in this field.