Greta Thunberg whipped up thousands of climate protesters in Switzerland today during a rabble-rousing speech where she warned world leaders 'you haven't seen anything yet'. The 17-year-old figurehead of environmentalism addressed the crowds crammed into the square in Lausanne ahead of next week's Davos summit where some of the planet's most powerful movers and shakers will get together to map out responses to global challenges. In a withering assessment of ...