Methane measurements collected during a scientist’s 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 California with oil and gas production. He found that methane concentrations exceeded the levels estimated by the U.S. Department of Energy, particularly in areas near industrial fossil fuel extraction sites. The results point to the importance of targeting these “fugitive” methane emissions in parallel with efforts to reduce CO2 emissions. Leifer’s findings were published in the journal Atmospheric Environment.