This chapter explores the possibility of extending Sen's and Nussbaum's capability approach to the question of ecological obligations to future generations. It is argued that we can extend capability protection to future generations, but this leaves open which resources such a theory is to leave to future generations. The chapter argues that the influential views of Rawls and Solow, which hold that these resources should be conceived in terms of ‘total capital’, cannot be accepted by a capability approach because of their assumption of substitutability between natural and human-made capital. It is proposed that a capability theory of justice best fits with a combination of two ecological approaches: the ecological space approach and Herman Daly's resource rules.