Very promising news. Looks like storing carbon dioxide deep below the earth's surface might be a safe, long-term sequestration solution. University of Leeds (they're busy there) research found that porous sandstone, drained of oil, provides a safe reservoir for CO2. Investigator Stephanie Houston examined water pumped out with the oil and found it unexpectedly rich in silica, revealing that silicates had dissolved in the newly-injected seawater in less than a year—much faster than predicted. This is the type of reaction needed to make CO2 as stable as, say, the dissolved carbonate in still mineral water. It's also what's needed to prevent the captured CO2 leaking back to the surface at some future (catastrophic) date.
Julia Whitty is Mother Jones' environmental correspondent. You can read from her new book, The Fragile Edge, and other writings, here.