Greta Thunberg is an internationally-known climate activist—and she’s only 17 (b. 2003)! She's been Time magazine’s “Person of the Year,” nominated 2x for a Nobel Peace Prize, & made the Forbes list of the “World’s 100 Most Powerful Women” in '19. Known for her straight-forward speaking manner—both in public & to political leaders—she has criticized heads of countries for failing to take action about climate change which she believes will be responsible for an existential crisis for humanity.