It is the policy-maker’s job to work out solutions to problems. The writer’s role is to direct the reader to the most important problems and make them worry about them. So it does not matter that some of Sven Lindqvist’s past pessimism, about third-world debt and ozone depletion for instance, have not been borne out. “I am not a fortune teller,” he said, and nor should any artist pretend to be.