Singer-songwriter Charlie Puth dazzles in a performance of his effortlessly catchy hit "Attention" and an impeccable cover of Stevie Wonder's "You and I", live from the TED Countdown stage.

Combining new TED Talks with live performances, short films, expert conversations and more, the Countdown Global Livestream event vividly explains the climate crisis, focusing on solutions and calling for leaders and citizens everywhere to step up. Hosted by Latif Nasser, with appearances by AsapSCIENCE, Don Cheadle, TED science curator David Bi...