From today’s WSJ:
Robert Watson and Mohamed El-Ashry
This month’s Copenhagen talks focused on the leading climate change culprit: carbon dioxide. But reversing global temperature increases by reducing carbon emissions will take many decades, if not centuries. Even if the largest cuts in CO2 contemplated in Copenhagen are implemented, it simply will not reverse the melting of ice already occurring in the most sensitive areas, including the rapid disappearance of glaciers in Tibet, the Arctic and Latin America.
So what can we do to effectively buffer global warming? The most obvious strategy is to make an all-out effort to reduce emissions of methane.
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.
Yet global discussions about climate and policies to date have not focused on methane. Methane is formally in the “basket” of six gases targeted by the 1997 Kyoto Protocol. But its value is counted as if it has the same lifetime as carbon dioxide.
This ignores its much larger, near-term potential. As a result, methane represents only about 15% of the projects under the Kyoto Protocol’s emissions offset program. And it is not a major focus of climate protection programs in any nation.
This is huge missed opportunity, and not just for the climate. Methane also forms ozone, the smog that severely damages food crops and kills tens of thousands each year by worsening asthma, emphysema and other respiratory diseases
The rest here.