Yale Environment 360: Methane measurements collected during a scientists road trip across the U.S. indicate that local emissions of the potent greenhouse gas are higher than previously known in many regions. Using a gas chromatograph mounted to the roof of a rented camper, Ira Leifer of the University of California, Santa Barbara, collected air samples from Florida to California, finding the highest methane concentrations in areas with significant refinery activity such as Houston, Texas and in a region of central...