As a consummately effective ‘boundary term’, able to link disparate groups on the basis of a broad common agenda, ‘sustainability’ has moved a long way from its technical association with forest management in Germany in the eighteenth century. In the 1980s and 1990s it defined – for a particular historical moment – a key debate of global importance, bringing with it a coalition of actors – across governments, civic groups, academia and business – in perhaps an unparalleled fashion. That they did not agree with everything (or even often know anything of the technical definitions of the term) was not the point. The boundary work done in the name of sustainability created an important momentum for innovation in ideas, political mobilisation, and policy change, particularly in connection with the UN Conference on Environment and Development (UNCED) held in Rio in 1992. All this of course did not result in everything that the advocates at the centre of such networks had envisaged, and today the debate has moved on, with different priority issues, and new actors and networks. But, the author argues, this shift does not undermine the power of sustainability as a buzzword: as a continuingly powerful and influential meeting point of ideas and politics.