Real Climate gives the recent methane news some proper context. The bottom line is that since methane is a short lived GHG it would take a very sudden and very massive release of methane for it to have a large effect on the climate. And that is unlikely.
Methane is a short-lived gas in the atmosphere, so to make it rise, the emission flux has to continually increase. This is in contrast to CO2, which accumulates in the atmosphere / ocean system, meaning that steady (non-rising) emissions still lead to a rising atmospheric concentration…
The Siberian Arctic, and the Americans, each emit a few percent of global emissions. Significant, but not bombs, more like large firecrackers.
Read the whole thing for an abundance of detail.