Fred Pearce has a fascinating story in New Scientist this week on methane, which he dubs "the next fossil fuel." At first glance, the vast frozen deposits of methane clathrates around the Arctic look like an attractive stopgap solution for reducing emissions. Burning methane for fuel produces only half as much carbon-dioxide as coal does, and the clathrates themselves—found in the Siberian permafrost and in various seabeds around the world—are fairly accessible, it turns out. In Alaska alone, there's potentially enough methane to heat 100 million homes for a decade, and commercial production could get underway by 2015, according to the Energy Department. (Not discussed in the piece is how we would transport the extracted gas, which, alas, is no easy feat.)
But before anyone alerts Sarah Palin, there are downsides here. First, methane's still a fossil fuel, and there's little chance that countries can reduce their CO2 emissions 80 percent or more by 2050 by relying heavily on methane. But maybe it can help us transition away from fossil fuels. Okay. The other downside, though—and it's a big one—is that the best way to extract methane from the icy clathrates is to drill. And, as Pearce reports, large-scale drilling may run the risk of having the raw methane gas leak out or burp up into the air. And that could prove catastrophic: On its own, methane is a much more powerful greenhouse-gas than carbon-dioxide—about 25 times more adept at trapping heat from the sun.
Incidentally, in the same issue of New Scientist, UC Berkeley professor Kirk Smith also has a piece on methane. Smith is discussing straight-up methane gas, rather than burning methane for fuel. (Just so we're clear: Methane itself is 25 times more powerful at warming the earth than carbon-dioxide; but burning methane for fuel creates plain old carbon-dioxide—though less of it than burning coal does.) Smith points out that about half of the Earth's current warming has been caused by methane, and, because it doesn't last in the atmosphere as long as CO2, methane's technically easier for us to clean up.
As such, Smith argues, dealing with methane should be a top priority in global climate efforts—it would give us a bit more breathing room in the race to cut greenhouse gases. Methane emissions come from three main sources: leaks from oil and gas wells; landfills and animal waste; and agriculture—mainly rice paddies and livestock emissions. Regulating livestock production always ends up being hugely controversial, but plugging leaks in fossil-fuel systems and changing the way we handle waste shouldn't prove too difficult, and it'd lead to huge short-term gains.
Oh yeah, one more story on methane. Drilling in the clathrates could accidentally release methane gas into the air, which would be bad. But there's another way some of that stored methane could get released—if ocean temperatures start to rise or permafrost starts to melt. (A decade ago, clathrates on the seabed near California vanished when El Nino raised ocean temperatures by a mere 1C.) This is one of those "feedback mechanisms" scientists talk about in the context of climate change—rising temperatures lead to the release of methane into the atmosphere, which in turn jacks up temperatures further… Back in the June issue of Scientific American, Sarah Simpson had a good piece exploring how worried we should be about this process. (Short version: It's scary, and one possible solution involves wooly mammoths, which I won't even try to recap.)