Judith Curry, a true climatologist, explains the basics. She headed the department of earth and atmospheric sciences at the Georgia Institute of Technology until she gave up on the academy so that she could express herself independently. ‘Independence of mind and climatology have become incompatible,’ she says. She continues: ‘There is warming, but we don’t really understand its causes. The human factor and carbon dioxide, in particular, contribute to warming, but how much is the subject of intense scientific debate.