Isn't that the point? Natural gas is 95 percent Methane.
I wondered how much methane is “leaked” by natural sources? I found this:
http://www.epa.gov/outreach/pdfs/Methane-and-Nitrous-Oxide-Emissions-From-Natural-Sources.pdf
Lots of shaky “science” there...
One ironic tidbit is that draining wetlands reduces methane emissions.