To even make a dent in Earth''s phenomenal carbon dioxide budget surplus, scientists say humans need to begin thinking about capturing large amounts of carbon and burying it. Not hundreds of tons, not even thousands, but millions of tons of carbon dioxide per year.

So where do we put it? The standard answer is in old oil and gas fields, which the U.S. Department of Energy estimates could hold around 90 billion tons of CO2 (just two years of global output). If, however, we could reliably hold CO2 in underground salt lakes, called saline aquifers, we could store 10 to 40 times more than that. With this in mind, researchers at the University of Calgary in Alberta teamed up with industry for the Wabamun Area CO2 Sequestration Project (WASP). David Keith, the project's principal investigator, says they are in the early phases of scouting an area in central Alberta to potentially store around a billion tons of carbon dioxide over the next 50 years. Unlike other projects on this scale, the site is not a former oil field, and although it is right next to some coal plants, it has never been mined (because the only thing down there is saltwater). If it works, industry would have a way to store carbon on a large-scale, and therefore affordably.

"The scientific community really loves the idea of doing very finely instrumented, small-scale tests," says Keith, "but I don't think that will answer the questions we need to answer to move this forward at a large scale."

Master's student Chris Eisinger holds out cores of porous stone that have been drilled out of the potential sequestration site in Alberta. Behind him is a giant screen showing the geology of the site.