In this paper we develop a conceptual framework to empirically analyse conceptualizations of ‘justice’ in the context of profound transformations of the earth system. Equity and justice have become central issues in public discourses, political documents and research agendas addressing global environmental change. However, what justice implies in practice is often elusive. While references to ‘justice’ in global change research are becoming more frequent, its empirical content varies, remains vague, and conflicting interpretations abound. The conceptual framework that we advance seeks to bring structure, clarity, simplicity, and comparability among different interpretations of justice in global change research. It reduces the wealth of five broad normative approaches (liberal egalitarianism, cosmopolitanism, libertarianism, the capabilities approach, and critical approaches) to systematic, parsimonious answers on three key concerns any analyst of planetary justice is facing: the subjects of justice and their mutual relationship; the metrics and principles of justice; and the mechanisms on the basis of which justice is pursued. Our framework is designed to be used in empirical analysis. We hence illustrate its usability by empirically investigating two important recent policy documents: the 2030 Agenda for Sustainable Development, as the main directional policy document at the international level; and the founding documents of the ‘Future Earth’ programme, a major international research platform aiming to provide knowledge and support for sustainable transformations at planetary scale. Our analysis reveals the incoherence of the normative positions behind these two major political and scientific visions for our future; discusses the implications for adequately responding to the multiple global sustainability challenges we are facing; and highlights the need to carefully scrutinize the underlying conceptualization of justice in any programme, institution or scenario-building process that aspires to work towards more just societies.