While power plants that burn natural gas produce about half as many carbon emissions as those that burn coal—the dirtiest but still dominant source of U.S. electricity—there is little data on the amount of methane being produced by the boom in natural-gas drilling across the country. Scientists say methane has 20 times more impact on climate change than carbon dioxide.
“The greenhouse-gas footprint of natural-gas production is something that needs some really careful scientific and federal studies rather than making generalizations about it,” said John Deutch, chairman of an Energy Department advisory committee on shale gas. He spoke at the IHS Cambridge Energy Research Associates annual conference this week, where the focus has been largely on natural gas.
Despite this uncertainty, President Obama has thrown his support behind natural-gas development, precisely because the energy source is cleaner than coal-fired power. Recent discoveries of shale natural gas all over the country promise the United States decades of the domestic energy source. But environmentalists are concerned about moving too quickly to natural gas without knowing its full impact on climate change.
“I’m worried insofar as we don’t have a handle on exactly how much methane leaks,” said Mark Brownstein, deputy director of the energy program at the Environmental Defense Fund, one of the few environmental groups working with industry on natural-gas issues. “If we’re not doing anything to gather the data and we’re not doing anything to cure the leaks, then yes, I do worry. This is a problem that we should be able to get a handle on and solve.”
Shale gas presents the country with several challenges, including concerns about water contamination associated with a controversial extraction method called hydraulic fracturing, along with the fact that near record-low gas prices are reducing the incentive to drill. But the lack of information about methane emissions from gas production may be the biggest problem of all, because it means the nation could be blindly moving toward an energy source that could cause irreversible damage with respect to climate change.
EDF is working with seven oil and gas companies, including Royal Dutch Shell, on a study evaluating methane emissions during the entire production cycle for shale natural gas, including hydraulic fracturing, which injects large amounts of water, chemicals, and sand into a well at high pressures to break up rock and release gas.
“This is an issue we need to take seriously,” Royal Dutch Shell CEO Peter Voser told hundreds of oil and gas executives at the CERA conference. “Clearly more research and hard data are needed.”
The Environmental Protection Agency is working on regulations to limit methane emissions from gas wells, but the lack of data could slow down that process as well.
