Farther down the road, direct production of hydrogen—a potential energy carrier with few known environmental drawbacks—might be possible. "Zapping the methanogens and accelerating the syntrophs, plus some clever engineering, may enable hydrogen production—but that's much more difficult, " Larter says. "If you could recover molecular hydrogen from the reservoir, you've got a zero-carbon energy source from fossil fuel."
In the meantime, the process shows the power of microbes to literally change the world. "Most of the world's oil has been generated by microorganisms over geologic time scales," Head says. "Very small microorganisms have global effects."