Injecting man-made carbon dioxide beneath ocean sediments hundreds of meters thick could be an ideal storage solution for the environmentally damaging substance, contends Daniel P. Schrag, director of Harvard's Center for the Environment, and his colleagues at Harvard, the Massachusetts Institute of Technology, and Columbia University. Staff file photo Jon Chase/Harvard News Office |
Deep-sea sediments could safely store man-made carbon dioxideSeafloor within U.S. territory could permanently hold thousands of years' worth of nation's outputAugust 8, 2006By Steve Bradt
An innovative solution for the man-made carbon dioxide fouling our skies could rest far beneath the surface of the ocean, say scientists at Harvard University. They've found that deep-sea sediments could provide a virtually unlimited and permanent reservoir for this gas that has been a primary driver of global climate change in recent decades, and estimate that seafloor sediments within U.S. territory are vast enough to store the nation's carbon dioxide emissions for thousands of years to come. Harvard's Kurt Zenz House and Daniel P. Schrag, along with colleagues at the Massachusetts Institute of Technology and Columbia University, detail the advantages of sequestering excess carbon dioxide thousands of meters beneath the ocean's surface in this week's issue of the Proceedings of the National Academy of Sciences. "Supplying the energy demanded by world economic growth without affecting the Earth's climate is one of the most pressing technical and economic challenges of our time," says Schrag, professor of earth and planetary sciences in Harvard's Faculty of Arts and Sciences and director of Harvard's Center for the Environment. "Since fossil fuels - particularly coal - are likely to remain the dominant energy source of the 21st century, stabilizing the concentration of atmospheric carbon dioxide will require permanent storage of enormous quantities of captured carbon dioxide safely away from the atmosphere." Schrag and his colleagues say an ideal storage method could be the injection of carbon dioxide into ocean sediments hundreds of meters thick. The combination of low temperature and high pressure at ocean depths of 3,000 meters turns carbon dioxide into a liquid denser than the surrounding water, removing the possibility of escape and ensuring virtually permanent storage. House and Schrag's co-authors on the PNAS paper are Charles F. Harvey at MIT and Klaus S. Lackner at Columbia. The research was funded by the U.S. Department of Energy, the Merck Fund of the New York Community Trust, and the Link Foundation. |
