Some energy experts say that even if supplies of natural gas remain abundant, it’s unclear to what extent power producers will switch to the fuel, and how long it will take if they do. Many gas advocates display a “practical naïveté” about the conversion of coal-fired power production, says David Victor, director of the International Law and Regulation Laboratory at the University of California, San Diego. “If you look at the quantity of gas needed to replace all the coal plants in the United States, you’re talking about increasing gas consumption by something like 50 percent,” he says. “It’s a huge number.” Such a large increase in production will require extensive shale drilling, some of it in heavily populated locations. And, he says, “we don’t know what [the shale-gas drilling] looks like on a truly massive scale.” Many of those advocating a large-scale shift to natural gas are “living in a dream world,” Victor says. “They haven’t worked out the practical details.”
Generating electricity with more natural gas and less coal could clearly decrease carbon dioxide pollution. Says Victor, “If shale gas plays out at very large volumes and at low cost, then it will be a cost-effective way of making substantial reductions in emissions.” But, he says, those reductions won’t be enough to meet the long-term goal of cutting the nation’s overall carbon dioxide emissions 80 percent by 2050, as President Obama and a number of other political leaders have advocated. The switch to natural gas, he says, “buys you a little time” before other changes can be made, such as introducing more wind, nuclear, hydroelectric, solar, and other zero-carbon power sources. “The concern is that natural gas is a bridge to nowhere,” Victor says. “And it could be a very costly bridge to an outcome that doesn’t readily get you to the 80 percent reductions.”
From a technology perspective, natural gas and renewable sources, such as wind and solar, could complement each other. Natural-gas-fired turbines could be used to generate electricity when the wind isn’t blowing or the sun isn’t shining. But the economic and political relationship between natural gas and renewables is more complicated. If federal and state policies continue to mandate that power producers use more renewables, the electricity industry is likely to concentrate its new capacity on those technologies while keeping its low-cost coal-fired power plants. Policy will drive the use of renewables, and economics will drive the use of coal. Natural-gas plants will be squeezed out.
Then again, a focus on natural gas as a way to trim carbon dioxide emissions could divert attention–and money–from the need for zero-carbon technologies. “I am a big fan of clean natural gas, but there is a very big danger of getting everybody revved up about gas and losing sight of the fundamental technological transformation that is needed,” says Victor.
The availability of vast natural-gas resources in the Marcellus shale and similar sediments around the United States has changed energy calculations in a fundamental way. The discovery of this large and seemingly economical new source of fossil fuel has surprised even geologists who have spent their careers studying the shale. Little wonder, then, that policy makers and politicians are just beginning to try to figure out what the discoveries mean.
It’s not clear how–or even whether–those responsible for energy policy will take advantage of the opportunity. At best, the newly identified supplies of gas will buy time, providing a chance to reduce greenhouse gases while more innovative technologies are developed and deployed. At worst, the country will burn through large volumes of this fuel only to find that we haven’t reduced carbon dioxide emissions very much–and that we’ve put off investing in research to create cleaner technologies.
David Rotman is the editor of Technology Review.