claim: While methane is a more potent greenhouse gas than CO2, there is over 200 times more CO2 in the atmosphere.
evidence: Methane in the Earth's atmosphere is a strong greenhouse gas with a global warming potential (GWP) 104 times greater than CO2 in a 20-year time frame; methane is not as persistent a gas as CO2 (assuming no change in carbon sequestration rates) and tails off to about GWP of 28 for a 100-year time frame.
category: Atmospheric methane