If we want to really do all we can to avoid catastrophic climate disruption, we can have cheaper, more immediate impacts by addressing methane sources, say former IPCC Chair, Robert Watson and UN Foundation Sr. Fellow, Mohamed El-Ashry:
Sometimes called the "other greenhouse gas," methane is responsible for 75% as much warming as carbon dioxide measured over any given 20 years. Unlike carbon dioxide, which remains in the atmosphere for hundreds of years, methane lasts only a decade but packs a powerful punch while it's there.
Methane's short life makes it especially interesting in the short run, given the pace of climate change. If we need to suppress temperature quickly in order to preserve glaciers, reducing methane can make an immediate impact. Compared to the massive requirements necessary to reduce CO2, cutting methane requires only modest investment. Where we stop methane emissions, cooling follows within a decade, not centuries. That could make the difference for many fragile systems on the brink.
I don't think we need to get caught up in an either/or between the heat trapping gasses, carbon dioxide (CO2) and Methane (CH4). But we should absolutely be doing everything we can to suppress all the human-caused methane sources we can, as the authors suggest. This is especially the case since, as they note, doing so provides multiple opportunities to convert a waste product (e.g., methane from landfills, cattle feedlots, and oil wells) into electricity.
The thing is, if we don't curtail humanity's methane emissions, they will go up as a consequence of warming itself, both from warming of the oceans and as a result of permafrost melting, which causes thousands of years of buried carbon to decompose.