Greta Thunberg’s mother, Malena Ernman is promoting her family’s new book, “Our House is on Fire: Scenes of a Family and a Planet in Crisis.” She is using her daughter’s story as a tool for publicity. If the phrase “our house is on fire” is familiar it is because Greta frequently uses it when speaking in public about climate change. The parents of Greta work in the entertainment industry so they crave the stage. Ernman is a well-known opera singer in Europe and Svante Thunberg, Greta’s father, is an actor. Both parents have essentially all but given up their own...