Greta Thunberg, a 16-year-old Swede, has been speaking to world leaders powerfully and effectively about the climate crisis. She is bold, articulate (even in English), and holds world leaders accountable for their negligence.
See what I posted to my blog on April 29, 2019:
http://parallaxperspectives.org/articles-videos-greta-thunberg-swedish-teenager-speaks-boldly-to-world-leaders-about-climate-crisis