To talk about the future, you have to first imagine there is one. This is a lesson learnt by some of the more intuitive among us – the fiction writer, say, who looks at the state of the world and traces the contours of a future path that is only, just now, a distant possibility. It’s a path carved from the imagination, but with both feet firmly planted in the present. Jump forward 50, 100, 1000 years, and in the writer’s imagination you will find our planet’s destruction, or maybe its future hope.