Activist Greta Thunberg speaks on September 20 at the Global Climate Strike event in New York City. (John Lamparski/WireImage)

Greta Thunberg, the prominent 16-year-old climate activist, says her autism is central to her advocacy. She says it helps her to see the world “from another perspective” and “do the same thing for hours.” The co-founder of Autistic Self-Advocacy Network says Thunberg’s and others’ openness about their diagnoses helps change public opinion and fight stigma about autism.