SOME OCEAN ORGANISMS LIVE ON METHANE
. . .methane is the primary food source for most microorganisms thriving in the ocean floor. At the surface. . .scientists discovered formerly unknown bacteria that use oxygen to feed on methane.
http://www.sciencedaily.com/releases/2006/10/061019100814.htm
Since methane is deemed to be a much worse greenhouse gas than CO2, I propose we develop flying microbes to cleanse the atmosphere.