I was going to say "not so hot" but...
methane, the chief component of natural gas, is escaping into the atmosphere in far larger quantities than previously thought, with as much as 7.9 percent of it puffing out from shale gas wells, intentionally vented or flared, or seeping from loose pipe fittings along gas distribution lines.
http://www.nytimes.com/2011/04/12/business/energy-environment/12gas.html?_r=1&hp