TIME'S Person of The Year 2019,  GretaThunberg began a global movement by skipping school: starting in August 2018, she spent her days camped out in front of the Swedish Parliament, holding a sign painted in black letters on a white background that read Skolstrejk för klimatet: “School Strike for Climate.” Since then she has addressed heads of state at the U.N., met with the Pope, sparred with the President of the United States and inspired 4 million people to join the global climate strike on September 20, 2019, in what was the largest climate demonstration in human history.  Margaret Atwood compared her to Joan of Arc. After noticing a hundredfold increase in its usage, lexicographers at Collins Dictionary named Thunberg’s pioneering idea, climate strike, the word of the year.