The Independent Evaluation Unit of the Green Climate Fund and the International Labour Organisation jointly undertake a rigorous and precise global evidence review of interventions that could be regarded as aiming at outcomes consistent with a just transition in non-Annex I countries. This approach paper describes this research in detail and sets out the realist approach to reviewing just transition. It identifies the need for a just transition, the paucity of evidence in non-Annex I countries and hence the case for this GCF–IEU / ILO evidence review. It also introduces the four systems to examine: energy, agriculture/food, infrastructure and ecosystem services. It also details the review's scope and objectives and explains the methods to be applied, including the search strategy, data screening, data extraction and management, data synthesis, and learning and uptake of findings.