LiveScience: Levels of methane, a climate-changing greenhouse gas, have been rising since 2007. But U.S. federal budget woes are shrinking the monitoring network that tracks greenhouse gases such as methane, which comes from sources as varied as fracking and cow farts. The National Oceanic and Atmospheric Administration (NOAA) monitors many potent greenhouse gases, such as methane, carbon dioxide and carbon monoxide, at observatories around the world. In the past six years, funding for part of the network ...