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Feature Articles
Editor's Note
Audubon View
Field Notes
Green Guru
Citizen Science
Earth Almanac
One Picture

Field Notes
News Articles
Renewable Energy: Lassoing the Wind
Global Warming: Get Down
Q&A: Philippe Cousteau Jr., Aquaman
Bird: The Conservation Front
Agriculture: Go Fish

Turtle races, mittened crabs, elephant birth control; more.


Global Warming
Get Down

Instead of pumping billions of tons of carbon into the atmosphere, we might start putting them back where they came from: under-ground. The oil industry has used the approach for three decades, injecting CO2 into reservoirs to force the oil to the surface. To see if long-term storage is both feasible and safe, the U.S. Department of Energy is funding projects to test various rock formations. To date the agency has earmarked $500 million, and the stimulus package slated an additional $3.4 billion to connect existing infrastructure with the technology. Burying CO2 involves capturing it from a source, like a power plant, compressing it into what’s called supercritical fluid, and injecting it into geologic formations thousands of feet beneath the surface. Impermeable layers, or “cap rocks,” above the formations prevent the gas from escaping. In oil and gas reservoirs, and in saline and basalt formations, CO2 mineralizes over decades or centuries, forming a harmless solid trapped indefinitely. In coal seams, CO2 adsorbs to the coal’s surface. With four years of small-scale injections under its belt, the Energy Department is ramping up its efforts. A five-year project launched this year will capture a million metric tons of CO2 from the Archer Daniels Midland ethanol plant in Decatur, Illinois, and inject it into a 6,000-foot-deep saline formation. While research questions and regulatory issues must be addressed before geologic storage goes commercial, the scheme holds “significant opportunity” to help combat climate change, says John Litynski, the agency’s project manager.—Alisa Opar

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