Direct Air Capture and How It Can Help Mitigate Climate Change
By Lucinda Peng
What is DAC?
A relatively new and promising technology, DAC (Direct Air Capture), has the potential to play a significant role in mitigating climate change through the direct removal of carbon dioxide from the atmosphere. Climate change is largely caused by an excess in greenhouse gas emissions, such as CO2, in the atmosphere, which traps heat from the sun and warms the planet. Some ramifications of climate change include rising sea levels, more frequent and severe weather events, and a loss in biodiversity.
DAC technology goes through multiple steps in order to separate CO2 from the particles of nitrogen and oxygen in the air. DAC facilities use gargantuan fans to suck in ambient or outdoor air and push it through a filter laced with chemicals. The CO2 reacts with these chemicals and sticks to it, while the other components of air pass through. Once the CO2 is removed from the filter through the use of heat, pressure, or other chemicals, the CO2 is mixed with water and injected into the Earth where it mineralizes and turns into stone.
What are the Pros of DAC?
In addition to mitigating climate change, one of the major advantages of DAC is its flexibility in location. DAC can be used to remove CO2 from the atmosphere anywhere, regardless of whether or not there are sources of emissions nearby. This makes DAC a versatile technology which can be used in both urban and remote settings.
Another advantage is DAC’s scalability. This means that it can be used to remove large amounts of CO2 from the atmosphere when necessary. This differs with other methods of mitigating climate change, such as planting trees, which have a lower limiting capacity on the ability to remove CO2 at a large scale.
What are the Cons of DAC?
Despite these advantages, there are some challenges associated with DAC technology. Since CO2 makes up a tiny fraction of the air in the atmosphere, DAC facilities must take in a lot of air. This process is energy intensive and can prove costly. For reference, there are only about 412 particles of CO2 in every 1 million particles of “air.” This means that DAC machines must sift through millions of pounds of air in order to grab CO2.
One of the current main challenges is cost, which is relatively high compared to other methods of mitigating climate change. Once DAC technology becomes more ubiquitous, it’s expected that the costs will decrease.
Where is DAC headed?
Currently, there are 19 direct air capture facilities in operation around the world, according to the International Energy Agency. Fifteen of these are operated by the Swiss company Climeworks, and its most recent DAC facility highlights both the promise of vacuuming up CO2 and the remaining hurdles to large-scale builds. Based on the statement of Net Zero by 2050 in the Paris Climate Agreement, DAC is scaled to capture almost 60 megatons of CO2 per year. Although this level of deployment is attainable, it requires several additional large scale demonstration plants to refine the technology and reduce costs.
While there are challenges associated with DAC, such as its current cost, it may be a promising technology that offers a versatile and scalable solution to mitigating climate change.
Works Cited
“Direct Air Capture – Analysis.” IEA, https://www.iea.org/reports/direct-air-capture. Accessed 26 Dec. 2022.
Foster, Joanna. “Carbon Capture: Reversing Climate Pollution.” Environmental Defense Fund, https://www.edf.org/article/carbon-capture-fight-climate-change-stop-climate-pollution. Accessed 26 Dec. 2022.
Nations, United. “Net Zero Coalition.” United Nations, https://www.un.org/en/climatechange/net-zero-coalition. Accessed 26 Dec. 2022.
Ryan, Jackson. “Machines That Suck CO2 out of the Air Promise to Reverse Emissions. Will They Work?” CNET, https://www.cnet.com/science/machines-that-suck-co2-out-of-the-air-promise-to-reverse-emissions-will-they-work/. Accessed 26 Dec. 2022.
