New York Times: Rather than focus on reaching a legally binding climate agreement, the United Nations should take a stronger role in making sure that countries promote the development and use of cleaner energy sources, Yvo de Boer, the U.N.’s former climate chief, said on Friday. At a time when the U.N.’s long-held ambition of reaching a new treaty to curb emissions blamed for global warming seems out of reach, Mr. de Boer said many countries, as well as companies, wanted “to be held accountable” …