Amid the welter of enthusiasm for lead-free petrol and green consumerism it is often forgotten that a foundation-stone of radical green politics is the belief that our finite Earth places limits on industrial growth. This finitude, and the scarcity it implies, is an article of faith for green ideologues, and it provides the fundamental framework within which any putative picture of a green society must be drawn. The guiding principle of such a society is that of ‘sustainability’ (now one of the most contested words in the political vocabulary; Dobson, 1998, ch. 2), and the stress on finitude and the careful negotiation of Utopia that it seems to demand forces political ecologists to call into question green consumerist-type strategies for environmental responsibility (Seyfang, 2005). In this respect it is the limits to growth thesis, together with the ethical conclusions to be drawn from ecocentrism and hybridity discussed in the previous chapter, that divides light-green from dark-green politics.