1. “You all come to us young people for hope? How dare you!”

At the United Nations climate summit, dozens of presidents, prime ministers and corporate executives sought to highlight their efforts to reduce planet-warming emissions.

The teenage Swedish activist Greta Thunberg wasn’t having it. “The eyes of all future generations are upon you,” she said, visibly angry. “If you choose to fail us, I say we will never forgive you.” Watch the video.