"“The phrase ‘A little child shall lead them’ has come to mind more than once,” Al Gore tells me in Davos, before sharing his favorite Greta moment. It was at the U.N. summit last fall. “She said to the assembled world leaders, ‘You say you understand the science, but I don’t believe you. Because if you did and then you continue to act as you do, that would mean you’re evil. And I don’t believe that.’” Gore shook his head in wonderment. “Wow.” He then gives a history lesson: “There have been other times in human history when the moment a morally-based social movement reached the tipping point was the moment when the younger generation made it their own. Here we are.”"