This chapter examines how notions of climate justice are forged and contested in the politics of experimentation. It starts by examining how the idea of climate justice has been approached to date, contextualizing the predominantly international-scale debates which have been dominant in the literature with more recent interventions from the perspectives of the literature on environmental justice (EJ) and urban political ecology (UPE). The chapter examines the ways in which the making, maintaining and living of climate change experiments appeals to various justice claims in different configurations, whilst also shaping the ways in which climate justice comes to be enacted or resisted. It argues that climate change experimentation is integral to urban politics. Treating climate justice as having three dimensions: rights, responsibilities and recognition. Considerations of environmental justice entail the recognition that climate change is entangled with ongoing social issues of energy poverty, urban health and access to service provision, and how co-benefits of climate responses should be constructed.