CO2’s Better Down Where It’s Wetter, Under the Sea

A state-of-the-art system aims to take carbon dioxide from the air and pump it below the seafloor, where it would eventually turn to rock.

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We know that limiting carbon emissions is key in the fight against climate change, but should we also be removing existing CO2 from the atmosphere? Climate modellers increasingly recognize that this will be a necessary part of achieving our goal of capping global warming at 2 °C.

The Pacific Institute for Climate Solutions (PICS) at the University of Victoria has announced a $1.5 million partnership titled ‘Solid Carbon: A Climate Mitigation Partnership Advancing Stable Negative Emissions’. The inter-disciplinary partnership will unite Canadian, European, and US scientists with the goal of adapting technologies to create a state-of-the-art COdisposal system. The four-year project began on Oct. 1, and the team hopes to have the technology employed globally by 2050.

“We have to get to net-zero,” said PICS executive director Sybil Seitzinger in a UVic press release. She added that decreasing the concentration of CO2 in the atmosphere is essential because we simply have not been able to reduce emissions quickly enough.

On paper, the technologies will remove CO2 from the atmosphere via Direct Air Capture (DAC) technology and then pump it below the seafloor among basalt rock. Here, the CO2 will mineralize and eventually become rock itself, locked away where it can’t do harm. The whole process will be powered by wind and solar energy.

It may sound unrealistic, but it’s been done before on land. In Iceland, scientists sequestered CO2, dissolved it using water, and then injected it into basalt rock through the land. The PICS partnership have their sights on the oceans because 90% of the Earth’s basalt rock is found beneath the ocean floors, and that means the tech could be put into operation globally.

However, translating this technology from land to a deep-sea operation will be a monumental challenge for the team.

“One key design challenge will be adapting direct air capture technology that has only been used on land to perform reliably on a floating offshore ocean platform that is powered by renewable energy,” said UVic research lead Curran Crawford, in the press release.

“Another challenge is that the basalt reservoirs we want to reach are 2,700 metres deep, so our team is engaging with offshore oil and gas drilling experts who have successfully built systems in the deep-sea environment.”

But their problems don’t stop here. There are legal gaps in the regulation of activity in the oceans as policymakers didn’t foresee the need for measures like these when existing laws were written.

“We need to better understand the laws affecting offshore carbon capture and storage to ensure future projects are conducted in a manner that not only helps to mitigate climate change, but is also safe and environmentally responsible,” commented Romany Webb from Columbia Law School in UVic’s press release.

The partnership’s prospective technology comes under the umbrella of ‘negative emissions technologies’, a term that broadly covers tech which removes CO2 from the atmosphere. Seitzinger agrees with other experts who believe reducing emissions will simply not be enough to achieve our climate change goals.

“Solid Carbon is a highly ambitious project with many barriers to overcome but if this team can advance the technology to a commercially viable stage by mid-century, it could be a major tool to combat climate change,” she said.

“Drastic reductions in greenhouse gas emissions are not enough — we need large-scale, permanent removal of excess carbon from the atmosphere.”

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Barry is a journalist, editor, and marketer for several media outlets including HeadStuff, The Media Editor, and Buttonmasher Magazine. He earned his Master of the Arts in Journalism from Dublin City University in 2017 and moved to Toronto to pursue a career in the media. Barry is passionate about communicating and debating culture, science, and politics and their collective global impact.