up to 61 percent higher than what the government says.
In a study published this week in the journal Atmospheric Chemistry and Physics, researchers say the largest concentrations of methane were found at ground sites in Pasadena and across eastern portions of L.A. County.
The research, however, did not find out where the greenhouse gas was coming from.
The methane sensor is operated by the Jet Propulsion Laboratory. It’s located about 5,700 feet up on Mount Wilson, and it measured emissions from September 2011 to October 2013.
California air quality regulators participated in the study with scientists at JPL, Caltech and the University of Michigan.
Although just a sliver of U.S. greenhouse gas emissions, methane is far more powerful than carbon dioxide at trapping heat in the atmosphere.
Charles Miller is a research scientist at JPL and a co-author of the report, and spoke to KCRW’s Steve Chiotakis.