From greenhouse gas to rock in 25 years

Newly published research by scientists with the Solid Carbon project shows that carbon dioxide (CO2) taken from the atmosphere and injected into the deep subseafloor off Vancouver Island may turn into solid rock in about 25 years.

Solid Carbon, an international research team led by Ocean Networks Canada (ONC), a University of Victoria initiative, and funded by a PICS Theme Partnership grant from the Pacific Institute for Climate Solutions, hosted and led by UVic, is investigating how to permanently and safely sequester CO2 as rock in the ocean floor.

The project is part of the emerging field of negative emissions technologies—climate solutions that reduce the amount of carbon in the earth’s atmosphere.

The new research, published this fall in Geochimica et Cosmochimica Acta, the journal of The Geochemical Society and The Meteoritical Society, shows through sophisticated modelling and simulations how captured atmospheric carbon injected into porous, basalt rock, such as that found under the Cascadia Basin, may interact with different minerals in the basalt, creating carbonate rock.

The natural layer of sedimentary rock on top of the basalt, composed of up to 800 metres of sandstone and siltstone, keeps a lid on these “ingredients” while this process occurs. This cap keeps the CO2 interacting with the basalt rather than escaping.

Benjamin Tutolo, a researcher with Solid Carbon and associate professor in the Department of Geoscience at the University of Calgary, says the research team projects that 25 years post-injection, 95 per cent of the CO2 will be mineralized.

“Once it’s down there, it’s not going to go anywhere for a long time,” he says.

“What we have shown in this study is that carbon dioxide can transform to rock within 25 years as opposed to cases where mineralization takes many millennia,” says Adedapo Awolayo, the research paper’s principal author and a former post-doctoral fellow on the Solid Carbon research team. 

The research also explored uncertainty by creating scenarios where the surface area of basalt that interacted with the CO2 varied. Even with these variations, the researchers still found mineralization could be expected within 100 years.

“The findings from this modelling of ocean basalt lay an incredibly strong foundation for our next steps,” says Kate Moran, ONC’s president and chief executive officer, who notes planning is underway for a Solid Carbon demonstration project in the Cascadia Basin.

If the demonstration project shows positive results, Moran says permanent apparatus could aim to start by injecting half a million tons of CO2 per year per sequestration site, potentially scaling up to more than 20 gigatons per year by 2100 with global deployment of the technology. Human activity adds around 50 gigatons of greenhouse gases to the atmosphere each year.

“It’s important that we do this work now,” Tutolo says, “because projections predict by the middle of the century, we need to be directly capturing 10 gigatons of CO2 per year out of the atmosphere.”

Tutolo is quick to point out, however, that carbon-capture and-sequestration technology doesn’t remove the need for decarbonization of a variety of industries.

“This is not a ‘get out of jail free’ card,” Tutolo says. “All pathways to remain under 1.5 degrees of global warming require the use of negative emissions technologies such as this, but we also need to decarbonize the economy to get there. We need both.”

Researchers with the Solid Carbon team are also exploring many other aspects of project implementation, from the best renewable energy source for the project, such as wind power, to the policy implications for various levels of government, and how best to involve communities and Nations who use and care for the Cascadia Basin.

Read more about the Solid Carbon project team and history at solidcarbon.ca.

The Pacific Institute for Climate Solutions develops impactful, evidence-based climate change solutions through collaborative partnerships that connect solution seekers with experts from BC’s four leading research universities. PICS is hosted and led by the University of Victoria in collaboration with the University of British Columbia, Simon Fraser University and the University of Northern British Columbia.

Ocean Networks Canada, an initiative of UVic, monitors the west and east coasts of Canada and the Arctic to continuously deliver data in real-time for scientific research that helps communities, governments and industry make informed decisions about our future. Using cabled observatories, remote control systems and interactive sensors, and big data management, ONC enables evidence-based decision-making on ocean management, marine safety and environmental protection. ONC also works in collaboration with educators, students, communities and Indigenous peoples on ocean monitoring initiatives along BC’s coast and in the Arctic.

UVic is a catalyst driving change and meaningful impact on a global scale through strong partnerships at home and internationally. In our teaching, research and operations—and through our local, national and international partnerships—the University of Victoria proudly supports and works to advance the United Nation’s Sustainable Development Goals (SDGs). UVic’s commitment to climate, environmental change and sustainability measures up—we are second in the world among universities for climate action as ranked against the SDGs. Learn more about UVic’s 2022 ranking by the Times Higher Education Impact Rankings.

Read more details about this research from PICS.

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A media kit containing high-resolution photos of the researchers and a microscopic image of solidified carbon are available in Dropbox.