Scientists seek source of giant methane mass over SouthwestScientists are working to pinpoint the source of a giant mass of methane hanging over the southwestern U.S., which a study found to be the country’s largest concentration of the greenhouse gas. The report that revealed the methane hot spot over the Four Corners region — where Colorado, New Mexico, Utah and Arizona meet — was released last year. Now, scientists from the University of Colorado, the University of Michigan, the National Oceanic and Atmospheric Administration and NASA are conducting a monthlong study to figure out exactly where it came from. The answer could help reduce methane emissions that contribute to global warming. Here are some key things to know:  Last year’s study by NASA and the University of Michigan was based on images from a European satellite captured between 2003 and 2009. They showed the methane hot spot as a red blip over the area, which is about half the size of Connecticut. The study found the concentration of methane detected there would trap more heat in the atmosphere than all the carbon dioxide produced each year in Sweden. Methane doesn’t last as long in the atmosphere as carbon dioxide, but it’s far more potent for capturing heat in the short term. FULL REPORT