New evidence that ancient volcanic rocks can store CO2
Researchers from the University of Edinburgh have identified several underground volcanic rock formations around the United Kingdom that could transform carbon capture and storage (CCS). The key finding is carbon mineralization: CO2 reacting with minerals in these rocks to form stable carbonates, effectively turning a greenhouse gas into solid rock. This natural process could provide a long-term, safe option for reducing atmospheric CO2 levels.
How mineralization works in volcanic rocks
Volcanic rocks, formed from cooled lava, contain minerals that readily react with CO2 under the right conditions. When CO2 becomes trapped underground, it can dissolve into water in the rock’s pores and react with calcium, magnesium, and iron silicates to create stable carbonates. This process occurs over years to centuries, gradually locking CO2 into solid rock and reducing the potential for leakage compared with conventional underground storage.
According to the Edinburgh-led researchers, these mineral-rich formations offer a natural containment system. The mineralization process is self-limiting and robust, creating durable storage that resists leakage even over geological timescales. In practical terms, the rocks could absorb CO2 from industrial sources or from the atmosphere and sequester it in a form that remains stable for millions of years.
Why this matters for climate strategy
As nations seek scalable, secure solutions to meet climate targets, mineralization in ancient volcanic rocks presents a compelling option. Unlike some CCS methods that require ongoing monitoring and high-pressure containment, mineralized CO2 is less prone to leakage because it becomes a solid mineral. This makes it an attractive complement to other decarbonization efforts, potentially reducing the burden on power plants and heavy industries to achieve near-term emission cuts.
Britain’s geological landscape offers a natural “storage library” for carbon. The Edinburgh team mapped underground volcanic formations with favorable mineral mixes and porosity, identifying regions where CO2 could be injected and immediately begin forming carbonates. While the concept is promising, researchers emphasize that pilot projects, regulatory frameworks, and thorough risk assessments are essential before large-scale deployment.
Practical challenges and next steps
Several hurdles must be overcome to turn this concept into a widespread solution. Technical challenges include optimizing injection rates, ensuring uniform mineralization across large volumes of rock, and accurately predicting long-term behavior under varying pressures and temperatures. Regulatory and public acceptance considerations also play a role, as with any CCS technology. The Edinburgh researchers plan to collaborate with industry partners to design pilot tests that demonstrate mineralization efficiency, monitor storage integrity, and assess economic viability.
In addition to technical work, policy makers will need to consider land use, permitting processes, and infrastructure needs for CO2 transport to suitable rock formations. The potential to combine mineralization with other climate strategies—such as renewable energy deployment and emissions reductions—could accelerate progress toward net-zero goals while providing a durable form of carbon containment.
A path forward for natural climate solutions
Mineralization of CO2 in ancient volcanic rocks highlights a broader shift toward nature-compatible approaches to climate change. By leveraging existing geological processes, scientists are exploring ways to achieve permanent or near-permanent carbon storage in a manner that aligns with long-term planetary stability. The UK study adds to a growing body of evidence that the Earth itself can act as a reservoir for human-made carbon when appropriate rock types and conditions are identified.
As research advances, mineralization could become part of a diversified CCS portfolio—used alongside direct capture technologies, afforestation, and energy transition efforts—to deliver robust climate protection and a future with lower atmospheric CO2 concentrations.
