ClimateWire: Barack Obama was considered a climate change savior 20 months ago, rushing into the White House with promises to price carbon, accelerate renewable energy technology and participate in a worldwide effort against global warming. He was a champion to environmentalists and sometimes described the atmospheric impacts of unregulated emissions as a threat to his own family. Global warming, he said in 2007, is not “a someday problem; it is now.” But the legislative remedy would have …