Direct Air Capture Of CO2: How It Affects the Air We Breathe

Why can’t we capture CO2 directly from the air and store it somewhere to tackle global warming? That is the question many engineers and scientists are asking in the quest to tackle the climate crisis.¹

But the answer is not as simple as it might seem. In recent years, there has been growing interest in direct air capture (DAC) technology. In March 2020, the US government gave an unprecedented USD $24 million award for research into the field. “If we can figure out how to remove polluting emissions directly from the air, it would be a game changer in America’s fight against climate change”, said the Secretary of Energy, Jennifer Granholm.²

How does direct air capture technology work?

Direct air capture technology focuses on removing CO2 straight from the atmosphere and storing it. It may be stored underground, used as fuel or to make products. The UK-based Committee on Climate Change (CCC) says we also need engineering solutions to remove greenhouse gas emissions.³

How can direct air capture technology change the future of our air?

Direct air capture has the potential to reduce the amount of carbon dioxide in the air significantly. If the captured CO2 is stored underground, it would be permanently removed from the atmosphere. There are currently 15 direct air capture plants operating worldwide, according to the International Energy Agency (IEA). They capture more than 9 000 tCO2 a year. A bigger plant capturing 1 tonne of carbon a year is in advanced development in the US. There is strong commercial interest in the technology, especially from companies who plan to get their carbon emissions down to net-zero.⁴

Is direct air technology viable?

While there are plans to scale direct air capture technology, it is prohibitively expensive and relatively small scale. Currently, there is little indication that it can help us stop climate change, despite its immense potential. Capturing a tonne of carbon dioxide has fallen to USD $94 and $232. This is expected to fall further. But there is no financial incentive to remove and store carbon as of yet, despite media interest.⁵

Currently, most DAC plants are small and sell the captured CO2 for use in carbonated drinks, for example.⁶ While this industry and technology has the potential to help us slow down global warming, it is yet to prove itself.

1. The Engineer. (2021). Direct air capture: silver bullet or red herring? [online] Available at: https://www.theengineer.co.uk/direct-air-capture-net-zero/ [Accessed 22 Apr. 2021].
2. Energy.gov. (2021). DOE Invests $24 Million to Advance Transformational Air Pollution Capture. [online] Available at: https://www.energy.gov/articles/doe-invests-24-million-advance-transformational-air-pollution-capture [Accessed 22 Apr. 2021].
3. The Engineer. (2021). Direct air capture: silver bullet or red herring? [online] Available at: https://www.theengineer.co.uk/direct-air-capture-net-zero/ [Accessed 22 Apr. 2021].
4. Direct Air Capture. (2020). International Energy Agency. [online] 22 Jun. Available at: https://www.iea.org/reports/direct-air-capture.
5. Roberts, D. (2018). “Direct air capture” of carbon dioxide won’t solve climate change. [online] Vox. Available at: https://www.vox.com/energy-and-environment/2018/6/14/17445622/direct-air-capture-air-to-fuels-carbon-dioxide-engineering.
6. The Engineer. (2021). Direct air capture: silver bullet or red herring? [online] Available at: https://www.theengineer.co.uk/direct-air-capture-net-zero/.