Scientists point to volcanic rock formations as potential CO2 storage
Researchers from the University of Edinburgh have identified a network of ancient underground volcanic formations around the United Kingdom with the potential to permanently store carbon dioxide. The concept hinges on carbon mineralization, a natural process where CO2 reacts with minerals in rocks to form stable carbonates. If harnessed at scale, this approach could offer a long-term, low-risk method to remove CO2 from the atmosphere and keep it locked away for millennia.
How mineralization works in volcanic rocks
Mineralization occurs when CO2 gas or reactive carbonic solutions come into contact with certain rock types, especially those rich in magnesium and calcium silicates. Over time, the gas bonds with minerals to form solid carbonates like calcite or magnesite. The process is self-limiting and stable, reducing the chances of CO2 leakage compared to some storage methods. The UK study highlights underground volcanic formations that present favorable mineral-friendly conditions, such as the right mineral composition and adequate rock permeability to allow gas flow and reaction.
Why volcanic rock formations are promising
Volcanic rocks created by ancient eruptions can offer extensive reservoirs with the necessary porosity and mineral content. In the UK, several sites formed through past volcanic activity exhibit beds and fractures where CO2 could migrate and react with minerals. The essential advantage is permanence: once CO2 becomes a carbonate mineral, it becomes part of the rock matrix, effectively immobilizing it for geological timescales. This resilience makes mineralization a compelling option alongside other carbon capture and storage (CCS) strategies.
From lab to landscape: challenges and opportunities
Turning mineralization from a laboratory concept into a practical climate solution will require overcoming several hurdles. First, scientists need to confirm the rate at which mineralization can occur in real-world underground formations, which depends on rock chemistry, temperature, pressure, and the presence of suitable fluids. Second, large-scale CO2 delivery systems must be designed to transport the gas to these formations efficiently and safely. Third, monitoring and verification protocols are essential to ensure long-term stability and to address regulatory and public concerns about subterranean storage.
Potential implementation pathways
Experts are exploring multiple routes to deploy mineralization-based storage in the UK and beyond. One option is retrofitting existing CCS sites with mineralization-capable workflows, enabling the injected CO2 to convert into solid carbonate minerals as it travels through mineral-rich layers. Another path involves in situ mineralization, where CO2 is introduced into reactive rock zones directly underground. A third approach could combine mineralization with enhanced rock weathering at the surface, accelerating the supply of reactive minerals to underground reservoirs.
Implications for policy and climate strategy
If mineralization in volcanic rock formations proves scalable, it could complement other decarbonization efforts by offering a dependable, long-term sink for atmospheric CO2. Policymakers would need to develop robust regulatory frameworks, standardized monitoring, and transparent risk assessments to reassure communities and industry stakeholders. Incorporating mineralization into national climate plans could help nations meet ambitious emission targets while diversifying the toolkit for climate resilience.
Looking ahead
The Edinburgh study marks a promising step toward a practical use of ancient geological processes for modern climate goals. While more fieldwork, pilot projects, and interdisciplinary collaboration are needed, the potential to convert millions of tonnes of CO2 into stone could redefine how we think about long-term carbon storage. As researchers refine models and gather real-world data, mineralization in volcanic rock formations may move from curiosity to cornerstone of sustainable climate strategy.
