Article Photos: Energy experts say drilling can be made cleaner 1/1

FILE - In this Aug. 19, 2008 file photo, a combine cuts durum near an oil well on Aug. 19, 2008, in Tioga, N.D. The worries about what drilling does to the air are both global and local, with scientists concerned about the effects on climate change as well as the possible health consequences from breathing smog, soot and other pollutants. (AP Photo/James MacPherson, file)