China's 'green Olympics' threatened by smog

Beijing promised a "war on pollution" when it was handed the 2022 Winter Olympic Games in 2015, shutting coal plants and relocating heavy industries as the city sought to shed its status as one of the most polluted in the world. But with less than two weeks before the Games get underway on February 4, authorities are warning that the city's longstanding smog problem is threatening to resurface.