Methane (CH4) is a colorless, odorless, flammable, greenhouse gas. It
is released naturally into the air from marshes, swamps, rice
fields, ruminant animals (such as cattle), and sewage sludge. CH4 is
also released from methane-producing bacteria (methanogens) that live
in anaerobic places. [Solar Energy; v52n6; 467-477; 1994.] [Air, The
Nature of Atmosphere and the Climate; Michael Allaby; pages 39,40;
1992; Facts on File; New York] [Dictionary of Science; R.K. Barnhart;
page 398; 1986; Houghton Mifflin Company; Boston.]
