While methane has a much larger effect it also leaves the atmosphere much faster rate. Methane released to the atmosphere is gone in about 12 years while CO2 t

While methane has a much larger effect it also leaves the atmosphere much faster rate. Methane released to the atmosphere is gone in about 12 years while CO2 takes over 100 years. So over the lifetime of the gasses methane will have a smaller effect as it just does not stay around for as long. Also CO2 is mainly absorbed into the oceans acidifying them which is another huge issue we are facing now.