This is the first book-length treatment of the relationship between citizenship and the environment. Andrew Dobson argues that ecological citizenship cannot be fully articulated in terms of the two great traditions of citizenship - liberal and civic republican - with which we have been bequeathed. He develops an original theory of citizenship, which he calls 'post-cosmopolitan', and argues that ecological citizenship is an example and an inflection of it. Ecological citizenship focuses on duties as well as rights, and these duties are owed non-reciprocally, by those individuals and communities who occupy unsustainable amounts of ecological space, to those who occupy too little.