Climate change raises important questions of global distributive justice, which can be defined as the issue of how benefits and burdens should be distributed within and between generations. This article addresses two conceptual issues that underpin the relationship between climate change and the part of distributive justice concerned with the entitlements of future persons. The first is the role of reciprocity, conceived either as mutual advantage or fair play, in the allocation of distributive entitlements between generations. The second is the extent to which theories of ‘justice as reciprocity’ can ground duties of intergenerational justice that underpin radical policies to manage the causes and impacts of global climate change. I argue that theories of justice as fair reciprocity generate significant duties of environmental conservation, despite these duties not being owed directly to the not-yet-born.