The Hellisheidi Geothermal Power Plant in Iceland, the site of CarbFix’s first industrial operation. (Credit: CarbFix / photo by Arni Saeberg)

Many of Iceland’s spectacular landscapes are made of basalt – a volcanic rock formed when lava cools.

Scientists have found that by injecting carbon dioxide deep into basalt formations, they can create new minerals and lock that carbon underground.

Deirdre Clark is with a research collaboration called CarbFix. She says the process starts with capturing carbon pollution from a power plant and dissolving it in water.

“So you’re making a carbonated soda and then injecting it into the ground,” she says.

There, the dissolved CO2 reacts with elements within the basalt to form new minerals.

“So essentially you’re taking the gas and you’re turning it into rock,” Clark says.

Mineralizing CO2 is not a new idea, but Clark says basalt’s composition and high reactivity enable the process to happen faster than expected. In the CarbFix pilot site in Iceland, the team has shown that about 95% of the CO2 was mineralized in less than two years.

“So this is quite quick,” she says.

Basalt is one of the most common types of rock on Earth, so Clark says the CarbFix process could be used around the world. And that would help remove CO2 from the atmosphere for good.

Reporting credit: Sarah Kennedy/ChavoBart Digital Media.

Diana Madson

Diana Madson contributed regularly to Yale Climate Connections from 2014 to 2021. She enjoys exploring U.S.-based stories about unexpected and innovative solutions to climate change. In addition to her...