Barack Obama , Chinese leader pledge to work to reduce carbon emissions . Move comes before U.N . It is up to you to open the door , '' U.N. Secretary-General Ban Ki-moon said in a statement Monday . Climate Change Conference in Denmark . China and U.S. are largest producers of greenhouse gases . Obama , Chinese President . ##a do n't offer a solution .
Barack Obama , Chinese leader pledge to work to reduce carbon emissions . Move comes before U.N . Climate Change Conference in Denmark . China and U.S. are largest producers of greenhouse gases . Obama , Chinese President . ##a do n't offer a solution .