This chapter argues that racialised constructions of the Other deriving above all from European colonialism remain central to problems of climate, water and environmental security and insecurity, in both theory and practice. Thus on the one hand the chapter demonstrates that environmental and climate security discourse is premised on, and still today structured around, racialised assumptions about history, geography, nature and freedom. And on the other hand it shows that racialised colonial understandings of foreign peoples and their environments played a crucial role in constituting modern political identities, with reverberations for patterns of environmental security and vulnerability which are still very much with us today. This latter argument is developed through a case-by-case and comparative analysis of the historical and political–ecological origins of the major identity divisions within post-colonial Israel–Palestine, Cyprus and Sudan, this paving the way, in conclusion, for a set of reflections on the politics of identity and alterity under circumstances of accelerating climate change.