the question to ask is how much co2 do you get when 1 ton of methane breaks down in the atmosphere, since methane's lifetime in the atmosphere is short. the point still stands that even if ALL that methane were to be released in an INSTANT, any greenhouse effect is neglible compared to current co2 levels, so why should I worry about it?
I'll have to have another look at that article, but the important question is still: is this something new, or is the ecosystem adapted to it? Until we can answer that question, we won't know whether you should worry or not.
Methane as a component of the atmosphere has risen pretty much in sync with warming. When warming leveled off in 1998, so did methane concentration. But in 2008, methane started up again. Still too early to tell if warming started up again at the same time. Global temps were slightly higher during the latter half of the last decade than during the earlier half. I'm not expecting much change for another year, yet. Then we'll see.