Greta Thunberg has the world’s ear. The 16-year-old is saying the same thing, repeatedly: “Listen to scientists”. Thunberg is maddening for a commentariat of mostly middle-aged males who do not know how to characterise and categorise her, in order to neutralise her. Were Thunberg expressing herself through books, or on a TED stage, or as an academic on a lecture tour, or an actor, or even a scientist; the categorisation would be easy. Greta Thunberg would become just another well-categorised voice in the cacophony. But Thunberg is not an entertainer, or a bookseller, or a self-promoter. She is an idealist, using…