A conceptual paper published twenty years ago (Sharpley, 2000) concluded that sustainable tourism development is an unviable objective. Specifically, it argued that environmentally sound tourism development (sustainable tourism) is essential; sustainable development through tourism, however, is unachievable. Despite continuing alignment between tourism and sustainable development in both academic and policy circles, not only have the intervening two decades proved this argument in practice to be correct, but also there is little evidence of a more sustainable tourism sector. This paper, therefore, returns to the theoretical relationship between tourism and sustainable development, considering more recent transformations in understandings of the concept of development as well as contemporary approaches to sustainable development. Highlighting the controversy surrounding the continuing adherence to economic growth in development policy in general and tourism development in particular, it discusses sustainable de-growth as an alternative approach to development and, in the context of increasing concerns over climate change, the specific implications for tourism.