How Direct Air Technology Can Reduce Our Carbon Footprint
The global temperature is rising and poses an enormous risk to the world around us. CO2 emitted by fossil fuels is one of the largest contributors to the problem, accounting for 65% of global greenhouse gas emissions. To ensure our future’s security, scientists have been assessing how to reduce global warming, limiting global temperature rise to 1.5°C or less per year, and the recent increased use of carbon capture technology is one possible solution. However, the effectiveness of this technique is still controversial. Here’s what we know so far.
The best-known method for removing CO2 from the air is to improve carbon storage in natural ecosystems – this includes planting trees and storing more carbon in soil. However, as we continue to develop more urban areas and deforestation continues to rise, this solution presents some challenges. To combat these barriers, scientists are starting to promote direct air capture (DAC) technology.
According to the International Energy Agency (IEA):
“Direct air capture technologies extract CO2 directly from the atmosphere. The CO2 can be permanently stored in deep geological formations (thereby achieving negative emissions), or it can be used in food processing, for example, or combined with hydrogen to produce synthetic fuels.
Today, two technology approaches are being used to capture CO2 from the air. Liquid systems pass air through chemical solutions (e.g., a hydroxide solution), which removes the CO2 while returning the rest of the air to the environment.
Solid direct air capture technology makes use of solid sorbent filters that chemically bind with CO2. When the filters are heated, they release the concentrated CO2, which can be captured for storage or use.”
Progress Mixed with a Touch of Skepticism
In 2017, the first commercial plant for capturing carbon directly from the air opened in Switzerland. The Climeworks AG facility near Zurich became the first ever to capture CO2 at an industrial scale from the air and sell it directly to a buyer. Today, the company operates 15 direct air capture machines across Europe.
At the time, Christoph Gebald, co-founder and managing director of Climeworks, shared the following: “Highly scalable negative emission technologies are crucial if we are to stay below the 2-degree target [in global temperature rise] for the international community.”
However, many individuals believe DAC technology is not the solution to our global warming problem and have shared insights into why we should leverage alternative remedies.
First, DAC technology is expensive. Howard Herzog, Massachusetts Institute of Technology (MIT) senior research engineer, points out that the total system costs for air capture could exceed $1,000 per ton of CO2, which is ten times the cost of carbon removal at a fossil fuel plant. He elaborates, “At that price, it is ridiculous to think about [such technology] right now. We have so many other ways to do it that are so much cheaper.”
Second, DAC machines are energy intensive, and research suggests that direct air capture machines could use up to a quarter of global energy in 2100. However, new DAC methods are currently being introduced to help overcome this hurdle.
Those who want alternative solutions are promoting the idea of planting trees. During photosynthesis, trees consume carbon dioxide and release oxygen. Unfortunately, this solution alone is not a viable option. It must be accompanied by additional measures.
“Addressing climate change will require investment in technologies that help to limit future emissions, such as electric vehicles, and [promote] the drawdown of carbon from the atmosphere. Nature-based solutions can help with both of these, but we will need thousands of solutions in combination,” says Tom Crowther, a tenure-track professor of global ecosystem ecology at ETH Zürich and the chief scientific advisor to the United Nation’s Trillion Tree Campaign. He continues, “There is huge potential for direct carbon capture technology as part of a diverse climate plan.”
A Brighter Future at a Lower Cost
Once scientists can identify less costly DAC technologies that use less energy, they can help us meet the demands of the future. Not only can such technologies be replicated, but they also use less land and water than other negative emissions technology. In terrains such as Australia, where growing trees is not always suitable and solar energy is highly accessible, DAC technologies can be extremely useful.
With the right modifications, DAC technologies might be one of the best solutions for combating global warming. If we fail to change the dynamics we currently live in, the results could be catastrophic.
Klaus Lackner, director of the Center for Negative Carbon Emissions and a professor at Arizona State University, observes: “We started the industrial revolution with 280 parts per million in the atmosphere … By now we have 415 [ppm], and we are going up 2.5 ppm a year at this moment.” He continues, “The oceans have started to rise, hurricanes have gotten way worse, climate has become more extreme, and this will only get worse over the next decade.”
Thankfully, progress is being made. In the United States, the Department of Energy (DOE) announced in June 2021 that $12 million in deferral funding will be allocated to six research and development projects (R&D) that are advancing DAC technology.
“Across the U.S., in states like Arizona and North Carolina, brilliant innovators are developing direct air capture technologies that can extract carbon dioxide straight out of the air,” said Secretary of Energy Jennifer M. Granholm. “These DOE investments, and the ones we will make with President Biden’s American Jobs Plan, are crucial to advancing technology that will help us avoid the worst effects of climate change and achieve carbon neutrality by 2050.”
What Does the Future Hold?
This year, billionaire Elon Musk announced that he would donate $100 million toward a prize for anyone who comes up with the best carbon capture technology. His offer highlights the significance of these new technologies and brings renewed attention to their study and use.
Despite these efforts, however, costs continue to be an issue. “The best capture technology will reduce [associated] costs, but it will never be zero. Hence, even the best carbon capture technology will be useless if the world is not willing to put a price on carbon,” stated Berend Smit, professor of chemical and biomolecular engineering in the Department of Chemical and Biomolecular Engineering at the University of California, Berkeley. His research focuses on finding the optimal material for carbon capture.
As we wait for the discovery of new, more cost-effective methods, scientists and researchers are working to make current carbon capture technologies better. Every small step in the right direction helps.