Reuters: A tough political atmosphere in which Congress backed away from comprehensive clean energy and climate change legislation may have been the nail in the coffin for one of the voluntary carbon market’s early pioneers. The Chicago Climate Exchange (CCX) will discontinue its voluntary greenhouse gas cap-and-trade program next month, according to Intercontinental Exchange Inc., its parent company. In its place, CCX will launch a new registry program for 2011 and 2012 carbon offsets. The development…