Against the human experience of long-term stagnation and misery, the record of growing prosperity over the past two centuries and, in particular, the last 50 years, is astounding. Economic growth owes much to the mobilisation of resources and structural flexibility, but this depends on the 'software of economic development' - institutions, which change slowly. Now, old fears and growth-impeding policies are being justified on environmental grounds. One example is Jared Diamond's recent book Collapse: How Societies Choose to Fail or Succeed, which discusses the possibility of a swift descent of the world into social disintegration. To anyone familiar with longterm economic history and the theory of growth, the book is pure millennial pessimism. It could become self-fulfilling if environmentalist doomsayers win the political argument with the doers - the engineers, entrepreneurs and economists.