Carbon capture: So simple, rocks can do it

In an effort to find new ways to reduce atmospheric concentrations of greenhouse gases, US geologists have mapped rock formations that react naturally with carbon dioxide, pulling it out of the air.

Scientists at Columbia University’s Earth Institute and the US Geological Survey have published a study in which they generated a US map showing the location of 6,000 square miles of ultramafic rocks that are at or just below the Earth’s surface. Ultramafic rocks contain minerals that combine with carbon dioxide in a process known as mineral carbonation.

The researchers are looking for ways to speed up the mineral carbonation process in hopes that ultramafic rock formations could be used as giant sinks for soaking up human-caused carbon dioxide emissions. In nature, such rocks normally require thousands of years to absorb sizable quantities of carbon.

Sam Krevor, lead author of the ultramafic rock map study, said such formations in the US could potentially store more than 500 years’ worth of the nation’s carbon emissions. As an added benefit, many of those formations lie along the populous east and west coasts.

“We’re trying to show that anyone within a reasonable distance of these rock formations could use this process to sequester as much carbon dioxide as possible,” Krevor said.