Colorado unveiled new measures to reduce airborne emissions from oil and natural-gas operations amid worries by state residents that increased drilling would hurt the environment or their health. Gov. John Hickenlooper, a Democrat, unveiled the new rules on Monday, less than two weeks after four communities voted to halt hydraulic fracturing, or fracking. “Natural gas is a crucial part of this country’s future, but we need to address the anxieties and concerns of the public,” Mr. Hickenlooper said in an interview. “People want clean air and clean water where they live, and that is a legitimate expectation.” The state’s proposed rules include first-in-the-nation regulations to force energy companies to reduce the emission of methane, a greenhouse gas linked to global warming that is the major ingredient in natural gas. The rules also attempt to cut emissions of volatile organic compounds, which some scientists say raise ozone levels and contain […]