Iceland's Carbfix project turns captured CO2 into solid rock since 2012

Since 2012, Iceland's Carbfix project has been injecting captured carbon dioxide into volcanic basalt rock, where it mineralizes into solid stone within a few years. The process dissolves CO2 in water, pumps it over 2,000 feet underground, and lets natural reactions with calcium, magnesium, and iron form stable carbonate minerals. More than 95% of the injected CO2 turns to rock in under two years, making leakage nearly impossible compared to conventional gas storage. The project started at the Hellisheidi geothermal power plant and now also stores carbon captured directly from the air via Climeworks. The IPCC says carbon removal like this is needed alongside deep emissions cuts to meet climate targets. But the approach has limits: it requires basalt geology and large volumes of water, so it is not a universal fix. Still, it is one of the few permanent storage methods operating at scale today.