Washington Post: China announced Thursday that it will lower its carbon emissions relative to the size of its economy by as much as 45 percent by 2020, the official New China News Agency reported, and that Premier Wen Jiabao will participate in international climate negotiations in Copenhagen next month. The move by the world’s largest greenhouse gas emitter to announce a near-term target of a 40 to 45 percent reduction, coming a day after President Obama set U.S. climate goals for the talks, suggests …