Carbon sequestration promises to address greenhouse-gas emissions by capturing carbon dioxide from the atmosphere and injecting it deep below the Earth's surface, where it would permanently solidify into rock. The U.S. Environmental Protection Agency estimates that current carbon-sequestration technologies may eliminate up to 90 percent of carbon dioxide emissions from coal-fired power plants. While such technologies may successfully remove greenhouse gases from the atmosphere, researchers have now found that once injected into the ground, less carbon dioxide is converted to rock than previously imagined.