Greenwire: With White House Chief of Staff Rahm Emanuel’s departure, President Obama is turning to the journeyman sage who helped acquaint him with the nuances of energy policy as a new senator in Washington. Now he might steer a splintered debate on climate. Pete Rouse is part strategist, part Buddha, say those who know him. As incoming chief of staff, his well-worn relationships in Congress and relaxed attitude could be valuable for a president facing a larger force of Republican lawmakers …