During two days of intensive airborne measurements, oil and gas operations in Colorado鈥檚 Front Range leaked nearly three times as much methane, a greenhouse gas, as predicted based on inventory estimates, and seven times as much benzene, a regulated air toxic. Emissions of other chemicals that contribute to summertime ozone pollution were about twice as high as estimates, according to the new paper, accepted for publication in the American Geophysical Union 鈥檚 Journal of Geophysical Research: Atmospheres .