Republican presidential candidate, Texas Gov. Rick Perry, recognizes a face in the crowd as he takes the stage to speak to members of the South Carolina GOP during a lunch in Columbia, S.C., Friday, Aug. 19, 2011. (AP Photo/Brett Flashnick) The Associated PressWASHINGTON (AP) — Presidential candidate Jon Huntsman is pounding away at rival Rick Perry's skepticism of manmade global warming and criticism of the nation's central banker.Huntsman says those stands hurt the GOP and make the Texas governor come off as a less than serious national figure.Huntsman, a former Utah governor who was President Barack Obama's first ambassador to China, has trailed in early polls nationally and in early voting states. That's led his campaign to pledge more aggressive attacks on the top candidates.Perry, who entered the race last weekend and has surged to a prominent role, has provided Huntsman with an ample opening to take shots.