AP: City authorities are often better placed than national governments to combat climate change, New York City Mayor Michael Bloomberg said Saturday, vowing to promote the use of electric taxis as he takes over the leadership of a global coalition of major cities. The billionaire mayor urged delegates at the C40 conference in Hong Kong to wield the power of its large collective population, which accounts for about 1 in 12 people in the world. C40 is a coalition of 40 cities. It was founded in 2005…