From China, watching Copenhagen

China faces a serious challenge as its representatives head to the Copenhagen climate talks: how to continue to urbanize and modernize while keeping carbon emissions in check. That tension is in stark relief in the southwestern city of Chongqing, China’s largest city and one of the fastest growing. Every day, it adds 1,300 new residents ? and their environmental impacts. We check in with the BBC’s Quentin Sommerville, who is watching the developments in Copenhagen from Chongqing.