This article examines whether the widely accepted political theory contributions on fair burden sharing, harm avoidance and a just distribution of the remaining carbon budget can (and ought to) be incorporated or reflected in judicial reasoning on causation in systemic rights-based climate litigation. It explores whether a wider use of the European Court of Human Rights’ lenient approach to causation at the national level could help overcome some of the causal difficulties that might otherwise excuse wealthy developed country governments that are signatories to the European Convention on Human Rights from responsibility. The article also considers how rights-based arguments might be a way of operationalizing climate justice in judicial reasoning in systemic rights-based climate cases in Europe.