A growing body of work has explored the effects of visual imagery on shifting forms of environmental consciousness and politics. Circulating images of, for example, the 'whole Earth' have been ascribed agency in the emergence of new forms of planetary awareness and political globalism. This essay identifies a new form of global environmental image, in the shape of photographic montage depictions of future places transformed by the effects of climate change. Montage enables artists and designers to import the spatial formations of distant places into more familiar locations, in the process producing novel renderings of the interconnections of global environmental change. The future-conditional -'if x, then y' -has become a key register of scientific and artistic engagement with climate change, and practices of visual montage have offered means of reconciling the transformations of space and time in the imagination of putative futures. The essay situates such images within a longer lineage of depictions of the tropical and the ruined, and focuses on contemporary montage depictions of climate-change-induced migration. It argues that many of these 'global montages' problematically reinforce extant notions of geographical otherness. Yet montage, as a technique, also renders visible the choices, cuts, juxtapositions and arguments which lie behind any representation, thus offering the seed of a more reflexive mode of future-conditional image-making.