Listen MM, Methane is up to 21 times more potent a GG than CO2.
Actually, methane is more potent than that. Its global warming potential (GWP) is somewhere between 62 and 72 (I've seen both numbers in reputable sources), averaged over 20 years. For example:
Methane is a relatively potent greenhouse gas with a high global warming potential of 72 (averaged over 20 years) or 25 (averaged over 100 years).[1] Methane in the atmosphere is eventually oxidized, producing carbon dioxide and water. As a result, methane in the atmosphere has a half life of seven years (if no methane were added, then every seven years, the amount of methane would halve).
en.wikipedia.org
Adding in the number of years is important because its residence time in the atmosphere is much less than CO2--the above passage says 7 years, I've read in other places 10-12 years, but whatever--the exact amounts don't matter so much because we don't even really know how much methane is around. Huge stores of it are at the bottom of oceans, stored in frozen clathrates in seabeds and in permafrost. The biggest danger we face w/r/t climate change is the oceans warming up enough so that those stores of methane are released. If it happens, it could cause abrupt climate change that would end the world as we know it. It is unlikely to occur anytime in the next couple of centuries, but it is a worst case scenario that we should do whatever we can to avoid.
Cf
en.wikipedia.org
for more. |
