Summit of world 's largest cities meeting in Seoul to discuss climate change . Ex-U.S. President Clinton says cities must take lead with green policies . Initiative by cities began in 2005 in London . Comment:
Summit of world 's largest cities meeting in Seoul to discuss climate change . Ex-U.S. President Clinton says cities must take lead with green policies . Initiative by cities began in 2005 in London . U.N. to hold climate conference at end of year in Denmark .