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.