Researchers associated with MIT published a study today assessing how much space would be available if the United States were to start capturing and sequestering carbon dioxide emitted by coal-fired generation plants. A couple of things need to be said about this right off. First, the study does not actually say what an MIT press release says it says. According to the erroneous MIT release, the study "shows that there is enough capacity in deep saline aquifers in the United States to store at least a century's worth of carbon dioxide emissions from the nation's coal-fired power plants."
What the study actually says, according to the article abstract posted by the Proceedings of the National Academy of Sciences (PNAS), is that "in the United States, if CO2 production from power generation continues to rise at recent rates, then CCS [carbon capture and storage] can store enough CO2 to stabilize emissions at current levels for at least 100 years."
Those are quite different statements, obviously. Having enough space to store incremental increases in carbon emitted from fossil generation is not by a long shot the same thing as having enough space to store all carbon emitted.
But why state estimated CO2 storage capacity in terms of increases in carbon emitted, and why should we content ourselves with merely stabilizing emissions at current rates? Great strides are being made in green building, as William Pentland points out in a recent blog on the Forbes magazine site, and further energy conservation will result from the introduction of demand-response incentives as the smart grid gets built. So even if the electricity mix were to remain roughly what it has been in past decades, there's no reason why electricity demand necessarily should grow, and no reason therefore why there should be higher fossil emissions.
What is more, however, the generation mix is not remaining the same: The fossil element in the mix already is shrinking. New construction of coal plants has been stopped in its tracks nationwide, and cheap, lower-carbon natural gas is being substituted for coal in electricity generation. That trend is likely to accelerate as coal generation gets more expensive because of tightening clean-air regulation, whether or not a cap-and-trade system puts is a price on carbon. Meanwhile, zero-carbon wind turbines have been the fastest growing new source of generation for years, and zero-carbon nuclear is waiting in the wings.
All those factors help explain why the bloom is off what's gone by the name of clean coal, and that's not to mention the pervasive unease--registering so far mainly in Europe--about the whole idea of storing lots of carbon dioxide underground.
So, while it may be of academic interest to know that there is enough room in the United States to store additional carbon emitted by coal-fired plants in the coming years, it hard not to ask, at risk of being a little rude: so what? Efforts to learn how to capture carbon are stalling here and in Europe, and there are abundant ways of reducing coal generation and carbon emissions without resort to CC&S