NEW : ` ` The need to act is urgent '' in a range of problem areas , one scientist says . The Doomsday Clock moves ahead a year . A third of scientists cites a fresh risk from atomic weapons and a lack of arms talks .
NEW : `` The need to act is urgent '' in a range of problem areas , one scientist says . The Doomsday Clock moves ahead one minute . A panel of scientists cites a fresh risk from atomic power and a lack of arms talks .