The extreme inequality in South African education is well-documented by researchers. There is also a rich literature concerned with education for sustainable development (ESD) in the country. The relationship between these two phenomena has, however, been sparsely investigated. Drawing on biopolitical theory and fieldwork conducted in South Africa, this paper queries how ESD programmes handle the lifestyle gap that separates rich and poor populations. The article demonstrates how ESD, through ostensible sensitivity to local 'realities', is adjusted to comply with different socio-economic living conditions, and how different roles are assigned to rich and poor in the quest for sustainable development. This differentiation, it is argued, can be understood biopolitically. The paper further argues that the differentiation between populations in rich and poor settings implies a depoliticized notion of local 'realities' as something isolated and given, rather than relational and produced. While the overall findings suggest that ESD unfolds through a regime of practice wherein inequality has become effectively normalized, the paper also points to rare disruptive moments where the normal is rendered abnormal. Ultimately it is argued that the South African case is a useful entry-point for discussing generic problems of globally implementing ESD in an enormously unequal world.