Yale Environment 360: A single methane hotspot in the U.S. Southwest accounts for 10 percent of the nations total estimated methane emissions, according to an analysis by researchers at the University of Michigan and Caltech. The area is centered in New Mexico's San Juan Basin near the shared borders of Colorado, Utah, and Arizona -- the site of the largest and most active coalbed natural gas production operation in the U.S. Natural gas from the basin is more than 95 percent methane, a significantly more potent heat-trapping...