Methane (CH4) is a colorless, tasteless, odorless, saturated organic gas. Saturation means that each and every one of the four bonds the carbon molecule is capable of making is a single bond to another element, in this case, a molecule of hydrogen. Met hane is the main component in natural gas and is produced in the gut of some animals (especially ruminants and termites) by methanogenic bacteria as a metabolic product. Landfills, wetlands and especially rice paddies generate copious quantities of metha ne and release it into the atmosphere. It is estimated that 70% of the total emission of methane is anthropogenic (man induced) and thus could be influenced by human activities (Randyopadhyay et al., 1996).

Questions:

• What organisms produce and release methane gas?
• From where did the bulk of the natural gas sold today come?
• Who are the major consumers of natural gas?
• What can humans do to reduce the quantities of methane being released into the atmosphere?
• What effects will deforestation have on atmospheric methane concentrations?

Methane is the second most ubiquitous greenhouse trace gas, behind carbon dioxide (CO2). However, methane is much more effective at absorbing infrared radiation (about 20 times) than carbon dioxide. Being more reactive, the methane molecule has a much reduced life span than the more stable, less reactive, carbon dioxide (Singh and Singh, 1995). Research cites methane as the most rapidly increasing greenhouse gas, perhaps as rapid as 1% per year Blake and Rowland (1987).

Questions:

• What are current estimates of atmospheric methane concentrations?
• How do methane concentrations compare to those of carbon dioxide?
• How does methane effect the atmosphere, why is it considered harmful?
• Which countries add most to atmospheric methane concentrations?