A new report claims that the American shale boom has increased net global emissions of greenhouse gases, but on closer inspection seems to rely on some “analytical chicanery” to reach that conclusion. The Breakthrough Institute reports:
[I]n a recent report, which has been cited by the AP and Mother Jones, [CO2 Scorecard claims] that rising gas generation accounts for all of the increase in US coal exports. This analytical sleight of hand leads them to claim that fuel switching from high-carbon coal to lower carbon natural gas in the U.S. power sector has resulted in a net increase in global CO2 emissions.
If true, that would be a pretty serious blow against the shale boom’s green credentials. Shale gas displaces coal as a source of cheap baseload power, which this chart shows pretty handily, and it does so with just half the greenhouse gas emissions. There are other advantages that make natural gas—and the shale boom that’s supplying it here in the U.S.—a boon to Gaia, but its ability to help us wean ourselves off our dependence on dirty-burning coal is the reason why shale gas is fracking green. Which is why the claim made by CO2 Scorecard—that the shale gas boom has led to an increase in global emissions—is so serious. It’s a decidedly good thing, then, that that claim is looking awfully shaky under increased scrutiny from BI:
How does CO2 Scorecard reach this remarkable conclusion? First, by looking at year-over-year changes in generation shares between coal and gas and assuming that fuel-switching between coal and gas only occurs in years when coal generation goes down and gas generation goes up. Second, by assuming that gas has displaced zero-carbon nuclear and hydropower in recent years rather than coal. Third, by assuming that all of the increase in US coal exports has been due to coal that has been displaced by gas. And finally by assuming that all US coal exports are additive to total global coal consumption rather than displacing other sources of coal. Only by making all four of these assumptions, none of which can be supported empirically, can CO2 Scorecard make the extraordinary claim that the shift in the US power sector from coal to gas has resulted in increased emissions.
The piece then goes point by point and dismantles these assumptions, exposing some rather lax methodology (it’s a bit technical, but certainly worth taking the time to read in full if you find this subject interesting). Here’s the bottom line: natural gas is a cleaner fossil fuel than coal, and unlike renewables, it can supply power consistently (even on cloudy, windless days). We are well-served by unlocking new reserves of natural gas not just for the economic boost these plays provide, but also for their environmental benefits. One day, with the right technologies, we’ll be able to power society without relying on fossil fuels, but we’re not there yet. Until then, natural gas is one of our best options, and greens would do well to recognize the fracking boom for what it is: good news.