Over half of the world's population (3 billon people) now lives in urban environments. The combination of people, industry, and commerce enmeshed in environments over-determined by plans, designs, and configurations that continue to emphasize ease, efficiency, and spatial sprawl over ecological constraints and sustainability help to make urban environments the primary contributors to multiple types of ecological degradation. With this in mind, urban environments demand greater sustained theoretical and practical attention than has been and is the norm under status quo (...) approaches to urbanism that pay little regard to ecological constraints and under traditional models of environmentalism informed by an anti-urban bias. Fortunately, an emerging form of urban environmentalism exists that recognizes the central ecological role of urban environments. This emerging form of urban environmentalism also recognizes urban environments to be the places where environmental problems are often most severe and where environmental solutions are in most need of immediate implementation. The upshot of this dual recognition is that it is accompanied by a growing dual awareness of urban environmental problems and solutions. In this paper I argue that despite this dual recognition and awareness, a paradoxical form of inaction is the norm when it comes to implementing urban environmental solutions. I explain why this is the case by outlining what I call the paradox of urban environmentalism. I explain why the paradox should be considered one of the most significant problems of this new environmental century as well as that frame which opens the door to a new sense of what is possible in urban environments. In the process of considering what is possible, I arrive at some preliminary conclusions about a possible methodological role philosophers can play in helping to address this paradoxical inaction in the hopes of bringing about more sustainable urban environments. (shrink)