Natural gas, also known as methane, is a greenhouse gas that, when burned as fuel, produces about half the amount of carbon dioxide as coal. From a climate perspective, that makes it sound like a really good alternative to coal. The one problem: when released into the atmosphere, it's at least 35 times more potent than carbon dioxide, over a 100-year period. Since the fracking boom got underway, we've been producing a heck of a lot of the stuff, and we know that some of it is leaking.
Proponents of natural gas, when they even admit that leaks are occuring, say we should focus on fixing that problem, then continue on fracking until renewable energy catches up. "If extracted safely," President Obama promises, "it’s the bridge fuel that can power our economy with less of the carbon pollution that causes climate change."
But that argument is about as leaky as a natural gas well, according to a new study published in the journal Environmental Research Letters. Even if we could stop methane from escaping, it finds, we'd still be better off leaving natural gas in the ground.
That puts a bit of damper on Obama's speech at the U.N Climate Summit, when he boasted that the U.S. has made great strides in reducing our emissions -- because the increase in natural gas use was arguably the largest factor contributing to that decline. According to the study's authors, replacing carbon-intensive fuels with natural gas isn't a winning strategy in the long run: the most fracking could possibly lower U.S. emissions, through 2055, they found, is 13 percent. And that's with a renewable energy mandate, which would make it so that natural gas was only competing with coal. Absent any climate policy, or even with a carbon tax in place, natural gas would have little impact on emissions. By delaying innovations in green energy, they add, it could end up making climate change worse.
"Our results suggest we need a strong climate policy of one kind or another -- either a carbon tax, an emissions cap, or a renewable energy mandate -- if we want to make deep cuts in emissions," the study's authors explain. "One thing is clear, though: We can’t simply frack our way to low emissions."
Some complex modeling went into the analysis. But Steven Davis, an assistant professor of Earth system science at U.C. Irvine and the study's principal investigator, explains it best by putting the findings in terms of baked goods. "Cutting greenhouse gas emissions by burning natural gas is like dieting by eating reduced-fat cookies," Davis said. "It may be better than eating full-fat cookies, but if you really want to lose weight, you probably need to avoid cookies altogether."
Joe Romm takes that metaphor and runs with it. "Those reduced-fat cookies are not simply replacing full-fat ones," he writes, "they are also replacing fruits and other healthy snacks." Bring in the health threats posed by fracking, I'd add, and all of a sudden you're looking at cookies that might help you lose weight, but also might give you nosebleeds. And once you add methane leaks back in, says Romm, well, that's like spreading butter on your low-fat cookies. Which is disgusting, and, to bring us back to what we're actually talk about, means that any way you slice it, natural gas is not going to solve climate change.