Meet Greta Thunberg, the clever and resourceful climate activist who started a solo school strike, aged just fifteen, and inspired millions of young people to join her. Find out: How worrying about climate change made Greta ill, but taking action made her feel better; why a real life prince sailed Greta (and her dad) to America on a solar-powered yacht with no toilet; and why she calls Asperger's syndrome her superpower.