Knowledge base
• Methane (CH4) is a potent heat trapping gas, yet climate change proponents are more concerned with carbon dioxide (CO2) emissions.
This statement holds mainly because of four reasons. The first being that heat trapping CO2 emissions, as several studies indicate (Trenberth, K.E. et. al. “Climate Change 2007”, CUP, 2007; Forster, P.V., et. al. “Climate Change 2007”, CUP, 2007), is deemed responsible for most of climate change in the 1750-2005 epoch. The second reason is attributed to the fact that CO2 persists in the atmosphere for a considerable amount of time. While methane has an atmospheric lifetime of 10, meaning that its heat trapping abilities will fade within a decade, CO2 atmospheric lifetime is estimated to span between 50 and 200 years, hence CO2 will persist in the atmosphere for much longer. The third reason emanates from the fact that the amount of CO2 (~400ppm) found in the atmosphere outweighs the concentration of atmospheric methane (1,800 ppb). Last, CO2 receives more attention even though the global warming potential (GWP), which is a measure of how much heat one molecule of gas will trap relative to a molecule of CO2, of CO2 is 1/21 the GWP of CH4.