I believe methane is around 25 times more potent at trapping heat than CO2 (have seen different figures around 25ish). There is a much shorter half-life on that

I believe methane is around 25 times more potent at trapping heat than CO2 (have seen different figures around 25ish). There is a much shorter half-life on that methane, it degrades in the atmosphere much more quickly (<100 vs ~1000 years) than the very stable CO2 molecule. However we have to think of positive feedback loops. The methane will heat us much sooner, which will allow more ice melt, more methane emissions from the permafrost in northern climates, and accelerating the heating we've already seen in polar regions.