Clearing the AirBestselling environmental star Hannah Ritchie is back with a succinct, punchy new book that answers 50 of the key questions stopping us from tackling the climate crisis. 'We urgently need Hannah Ritchie' GUARDIAN 'Hannah Ritchie does for the environment what Hans Rosling did for health' BILL GATES We can't afford to delay climate action, but with all the shouting and disagreement it's hard to know where to turn. In her new book, bestselling