Agence France-Presse: Nations pledged to work together to improve the efficiency of energy-guzzlers from televisions to cars, showing practical cooperation on climate change despite a deadlock on sealing a treaty. Senior officials from economies that make up more than 80 percent of global gross domestic product agreed on 11 initiatives during talks in Washington, which betrayed none of the sharp divisions typical of climate negotiations. US Energy Secretary Steven Chu, who led the meeting, said …