Turning Carbon Dioxide into Stone in the Fight Against Climate Change

Scientists in Iceland have made an exciting breakthrough in carbon capture and storage (CCS) technologies by converting carbon dioxide into stone.

The project, named CarbFix, ran for two years and showed better-than-expected results in terms of the time it took for the gas to be solidified and the percentage of it which was nullified. The results of the study were published in the journal Science and are believed to signify a potential breakthrough in the fight against climate change.

Harmful gas turned into stone

The process involved pumping a mixture of water and carbon dioxide half a kilometre into basalt rock formations, near the Icelandic geothermal plant Hellisheidi.

The mixture reacted with the calcium magnesium found in the rock and created limestone, which should effectively trap the carbon dioxide in a solidified form indefinitely. “It’s no longer a gas,” explained Dr Jürgen Matter, lead author on the paper detailing the results of the project. “Basically carbon dioxide is converted into stone.”

In further encouraging news, the two-year study showed that up to 95% of the gas was captured and transformed into limestone during this time. Such a rapid turnaround is far quicker than many experts had predicted, with some projections estimating that the CCS process could take centuries or even millennia to complete.

With climate change a hot topic right now - especially in the wake of the COP21 talks in Paris last year – this breakthrough in CCS technology could represent a huge boon for the future of our planet.

Not the finished article yet

Though the study showed very promising results, there are still several teething problems to be worked out and improved upon. First and foremost, the process is an incredibly expensive one – the two years for which CarbFix ran cost a grand total of $10 million (roughly £7 million). Should the technique be used on a large scale, the costs would surely run into the trillions.

However, the project does provide a solution as to the question of where carbon dioxide should be stored once it is captured. Most existing CCS schemes involve injecting the carbon dioxide into abandoned oil wells, though monitoring it thereafter has proven to be tricky. By solidifying it and transforming it into limestone indefinitely, scientists believe they can use the natural abundance of basalt rock on the ocean floor to dispatch much of the atmospheric carbon currently troubling the planet.

As with any CCS system, further research will be necessary to ensure the process doesn't impact upon other greenhouse gases (GHGs) and pollutants. However, the early results are promising and supporters of the technology believe it can offer a viable form of climate change mediation.

Investment and support lagging behind technology

According to Dr Matter, the main obstacle to furthering this kind of research was resistance from politicians, governments and big business.

“Carbon capture is not the silver bullet, but it can contribute significantly to reducing carbon dioxide emissions,” he explained to the Guardian. “The engineering and technology of CCS is ready to be deployed. So why do we not see hundreds of these projects? There is no incentive to do it.”

Hopefully, studies like this one will encourage belief in the power of CCS technologies to mitigate the harmful effects of climate change and keep our planet beneath the universally agreed level of 2°C and the preferred target of 1.5°C.