Reduced CO2 storage capacity estimated to be just one-tenth of previous estimations

In a significant development, a study published in the prestigious journal Nature has revised the planet's capacity to store carbon dioxide underground safely. The research, conducted by researchers at the International Institute for Applied Systems Analysis in Austria, has applied a risk-based framework to produce a realistic global estimate of carbon storage capacity.

The study, co-authored by Alexandre Koberle, suggests that the revised global reserve of carbon dioxide, taking into account geological risks, proximity to population centres, and political constraints, is approximately 1,460 gigatonnes. This is a significant decrease from earlier projections, which suggested that wide-scale storage could help cut warming by 5 to 6°C, the reduction needed to align with the 2015 Paris Agreement. At current emission levels, the revised carbon storage capacity would last roughly 35 to 40 years.

The current global emissions are around 37 gigatonnes annually. This means that the revised capacity could potentially store less than half of the current annual emissions. This finding underscores the extreme importance of reducing emissions as fast and as soon as possible, a sentiment echoed by Matthew Gidden, the lead author of the study and a research professor at the University of Maryland.

In the realm of carbon capture and storage (CCS), several initiatives are underway. Greenlyte Carbon Technologies is developing low-energy capture processes targeting lower costs. The Brevik cement plant in Norway, owned by Heidelberg Materials, is installing equipment to capture up to 400,000 tonnes of CO2 annually, about half its emissions. The plant has already sold all net-zero cement output for 2025.

Another pioneering project is the Bonaparte CCS project near Darwin, Australia. This project has confirmed saline aquifer storage potential of more than 10 million tonnes per year. Carbfix in Iceland is also making strides in CCS, injecting CO2 into basalt formations where it reacts to form stable carbonates, storing about 12,000 tonnes of CO2 each year.

Climeworks' Mammoth plant in Iceland, launched in 2024, is designed to remove 36,000 tonnes of CO2 annually. The European Union (EU) has also set ambitious goals in this regard, creating a net-zero scenario envisioning the scaling of carbon dioxide detection and storage to more than five billion tons per year by 2050 as part of its Carbon Removal Certification Framework (CRCF) and the EU Green Deal aiming for climate neutrality.

However, Gidden emphasizes that while carbon storage is a limited tool in addressing the climate crisis, it should not diminish the urgency of reducing emissions. The reduction in warming that could be achieved by wide-scale carbon storage, according to the study, is about 0.7°C. This underscores the need for concerted efforts to reduce emissions and transition to cleaner, renewable energy sources.

Reduced CO2 storage capacity estimated to be just one-tenth of previous estimations