Could a rock cure climate change? Well, maybe—if it’s peridotite. Scientists have long known that it acts as a carbon sponge, sequestering CO2 in a limestone-like carbonate, but Peter Kelemen (above) and Jürg Matter have figured out how to put that reaction to work. After traipsing around the peridotite beds of Oman, the Columbia University scientists developed a process to enhance carbonation’s two key catalysts—heat and pressure—thus supercharging the rock’s carbon storage capacity a millionfold. To apply this on an industrial scale, the pair plans to drill into peridotite deposits and inject them with hot water enriched with carbon captured from power plants. A USGS study estimated that the East and West Coasts contain enough peridotite-like rock to suck up more than 500 years’ worth of future U.S. carbon emissions.
Kelemen and Matter are both at work on large-scale applications, but they’re already looking ahead to new schemes, namely drilling into underwater rock deposits to passively suck CO2 from ocean water.
“You’d be using seawater in equilibrium with the atmosphere,” Kelemen says. “And that would take carbon dioxide out of the atmosphere. If it works, then there’s really no reason why you couldn’t go forward within a couple of years.”