From the WP article you linked:
> 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 and tails off to about GWP of 28 for a 100-year time frame
And once you take positive feedbacks into account additional emissions can be problematic even within "short" timeframes.