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Where on Earth will we store all that captured CO2? Try the U.S. east coast


basalt-outcropCarbon capture and storage—sucking the CO2 from power plant or industrial smokestack emissions—has been cited by everyone from the Bush administration to the United Nations Intergovernmental Panel on Climate Change as a key technology in any effort to combat climate change. That's because the world—particularly China, India and the U.S.—burns a lot of coal.

Deep saline aquifers or nearly empty oil wells are a few of the possibilities for where to put carbon dioxide, but what might be even better is a volcanic rock known as basalt. That's because the rock both stores CO2 and, over a relatively short period of years, forms carbonate minerals with it—in other words, limestone.

Already, several pilot projects to inject CO2 into basalt and see how successfully it stores the greenhouse gas are under way, including off the coast of Oregon and beneath Iceland. In fact, the Iceland project has already begun to inject trace amounts of CO2 dissolved in water to form carbonic acid, which speeds the reaction with the volcanic rock, according to physicist Klaus Lackner of Columbia University. "They want to understand the plumbing," he told me this past November. "Drill back there 20 years from now, you shouldn't find any CO2 because it's all carbonate."

Now new research from Lackner's colleagues at the Lamont-Doherty Earth Observatory led by geophysicist David Goldberg, shows that vast deposits of basalt lie off the coast of Georgia, Massachusetts, New Jersey, New York and South Carolina. Even better, the risk of leakage from such storage is low since the overlying ocean forms a second barrier of protection for the injected greenhouse gas. Along these lines, the Sleipner natural gas project in the North Sea has successfully stored more than 10 million metric tons of CO2 for more than a decade. Just one of the formations identified in Monday's issue of the Proceedings of the National Academy of Sciences by Goldberg et al. off the coast of New Jersey could hold as much as 1 billion metric tons of CO2. Of course, the nations of the world emit more than 30 billion metric tons of CO2 per year.

Ultimately, the key will be determining that the CO2 can be safely stored for the long-term. Already, a proposed coal-fired power plant proposed in Linden, N.J. includes plans to pump captured CO2 emissions into an offshore sediment, albeit not a basalt one.

If CO2 emissions end up being captured at power plants, factories and other sources, the U.S. coasts in the East and Pacific Northwest might be well-placed to serve as repositories based on Goldberg's research—in lieu of the atmosphere, where the gas is currently wreaking havoc with the global climate. "The Siberian basalt traps, the Deccan flats in India," Lackner added, "there are enormous amounts of basalt [globally]."

Image: Basalt in Nova Scotia, Canada. Courtesy Paul Olsen / Lamont-Doherty Earth Observatory

The views expressed are those of the author and are not necessarily those of Scientific American.

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