An excess of carbon dioxide is endangering our planetary health, but new technologies could let us put it to good use. Eric Mack makes the case.
Imagine being able to run your gasoline-burning car with fuel that’s not the product of old dinosaur bones, but rather of molecules pulled literally from thin air. Imagine tipping back a carbonated drink whose bubbles are carbon dioxide taken directly from our atmosphere. And imagine a world in which a vast array of the industrial processes we all depend on in our everyday lives are reducing the dangerous levels of CO2 in our atmosphere rather than sending them ever higher.
In fact, you don’t have to imagine, because the science behind this vision is established. We have the ability right now to harvest the heat-trapping molecules transforming our climate and use them to replace the largest sources of greenhouse gas pollution. That turns a planetary pollutant into an industrial feedstock: the concept is akin to turning poison into medicine.
What we don’t have is scale. The technology, while young, is proven to work and developing quickly. Deploying it with the haste and scope required for maximum impact is largely a matter of economics and politics. Even these frequently tricky hurdles may not be as high as they appear – but we don’t have much time to do it in. The next decade will be critical: that’s why this technology is at its tipping point.
Last year, the International Panel on Climate Change estimated in a widely publicised and disturbing report that to avoid catastrophic change we must not only drastically reduce our carbon dioxide output, but also begin actively pulling about 20 billion metric tons of CO2 out of the atmosphere each year (IPCC, 2018). A suite of technologies known as “carbon capture and utilisation” could go a long way towards addressing the second part of the equation. While the name may sound drab and technical, these innovations could be one of our most powerful levers in addressing climate change.
With justifiable scepticism about our collective ability and will to reduce emissions quickly enough, carbon capture may be needed to stave off runaway climate change. And even if it isn’t, there’s still a long-term need to get excess CO2 out of the system, a process that could take an extremely long time if left to nature’s depleted capacities. As “carbon wrangler” Julio Friedmann wrote in 2018: “We have a moral responsibility to clean up our mess and restore the world’s atmosphere to how we found it.”
The basic concept behind capturing CO2 is to move vast amounts of air through a filter or solution that traps the carbon dioxide molecules. From there, it can be stored, used as-is or converted to a more useful molecule with the help of a little chemistry. Considerable attention has been paid to the idea of simply burying it underground: the idea that we can put it to good use has been comparatively neglected. But it is starting to gain traction.
A recent proposal suggests that the world’s air conditioners could also double as carbon capture systems, collecting CO2 and water vapor from the air (Dittmeyer, R, et.al. 2019). Simple electrolysis can peel H2 off the water and combine it with carbon dioxide to locally produce hydrocarbon fuel using the Fischer-Tropsch process.
Considerable attention has been paid to the idea of simply burying it underground: the idea that we can put it to good use has been comparatively neglected. But it is starting to gain traction.
Laboratory experiments have also used captured CO2, electricity and a little lithium to create carbon nanofibers (Ren, J., et.al. 2015) that can be used in the manufacture of everything from better batteries and golf clubs to aircraft.
Climeworks is one of a handful of companies that has taken similar technology beyond the lab and is already pulling CO2 directly from the air. The Swiss start-up has set the ambitious goal of removing one per cent of global carbon dioxide emissions by 2025. The company’s small, modular direct air capture system is up and running in Switzerland and other locations in Europe, including a small demonstration unit in Italy that will capture 150 tons of CO2 per year to be converted into natural gas fuel.
Canada’s Carbon Engineering has also been capturing CO2 for several years, converting it into liquid fuels that could be used in today’s cars, trucks and even commercial jets. CEO Steve Oldham claims the technology can be “scaled up to capture gigatons of CO2 directly from the atmosphere… we’re now ready to move into much larger scale.” The company published a breakdown of its technology in a peer-reviewed journal last year (Keith, 2018), and is aiming to scale up enough to pull a gigaton of CO2 from the air per year – more than two per cent of what the world emits in the same time-span.
One challenge for such firms is that current atmospheric CO2 concentration of over 400 parts per million is enough to significantly disrupt the climate, but it’s still a tiny percentage of the air overall. One answer to that is to go directly to the source of excess carbon emissions: a third start-up, Alabama’s Global Thermostat, has a design it claims can be easily retrofitted on to existing power plants and factories, catching much higher concentrations of carbon dioxide than that of the ambient air.
That makes engineering sense but is more contentious from a social perspective. There is considerable scepticism about the potential for these technologies to be used to “greenwash” continued use of fossil fuels. The Extinction Rebellion protestors, for example, have chosen 2025 as a target date for straight elimination of CO2 emissions because they don’t think we can rely on technological fixes to get the job done by 2050. There is precedent: carbon offset schemes and trading permits were previously pitched as ways to neutralise fossil fuel consumption, but have mostly proven to be ineffectual in practice.
That scepticism is intensified by deep-seated hostility to fossil fuel companies, who are backing carbon capture technology with both money – Carbon Engineering has raised a significant investment from names like Chevron and BHP Billiton – and marketing. Their interest is obvious: carbon capture could prolong the use of fossil fuels, and their existing business models. Even if it works, that would mean we’re not fixing the underlying problem – to say nothing of the other environmental consequences of fossil fuel use, from atmospheric pollution to industrial accidents.
Looked at from this perspective, finding ways to extract carbon dioxide could become part of the problem as opposed to part of the solution. As engineering professor Jennifer Wilcox, who literally wrote the book on carbon capture, puts it: “This approach is so alluring that it may even be risky… It may tempt people to continue to burn fossil fuels 24 hours a day, 365 days a year.”
It’s important to understand that if these technologies are going to help put the brakes on runaway climate change, they have to be just one part of a more holistic approach. We must avoid the temptation to capture some carbon from the air simply to justify increasing the rate at which we burn legacy fuels pulled from the ground. In fact, the whole concept of carbon capture and utilisation is more or less pointless unless each part of the process, from capture and processing of CO2 into a raw material to its downstream fabrication into a commodity or saleable product, is powered by renewable sources of energy as much as possible.
In order to make both the economic and the environmental parts of this equation add up the key will be scale.
To remove CO2 at the scale needed to save places like Bangladesh and Miami Beach from the ravages of climate change, we need to harness the same scalable market forces that drove decades of CO2 pollution. Fortunately, carbon dioxide molecules can be converted into a wealth of useful products people will pay for: ultimately, it could even replace oil and gas as the primary feedstocks powering our economy.
In the short term, the most likely uses are to turn it into substitutes for fossil fuels, as Carbon Engineering is doing. It can also be used to substitute for solid coal. Burning these fuels does release the CO2 into the atmosphere again, but it is much closer to a neutral impact on the climate and displaces the far more negative impacts of traditional coal.
If these technologies are going to help put the brakes on runaway climate change, they have to be just one part of a more holistic approach.
CO2 can also be “locked away” for a little bit longer when it is converted into things like supercapacitors, building materials and composites for the manufacture of a wide array of products. It’s even possible to convert it into breathable oxygen and consumable food and drink. According to a report by Carbon180, a think tank with a mission to ‘transform carbon from a liability to an asset‘, the worldwide total available market for so-called “carbontech” is nearly $6 trillion per year, including $3.82 trillion in CO2-based fuels alone (Jacobson and Lucas, 2017).
These estimates are the best possible scenario – a world in which everything that can be made from collected CO2 actually is.
It may seem like a dream that is beyond pie in the sky, but the potential uses of carbon dioxide as a feedstock for all sort of materials, from fuel to steel to plastics to food, is really only limited by demand and price. Right now it costs about $500 - $600 to pull a metric ton of CO2 out of the air with only three small start-ups actively doing so at what amount to pilot plants. That price needs to come down closer to $100 to begin to be competitive in the existing CO2 market as it stands today.
Carbon Engineering claims it can cross that threshold within a few years, as it moves to build commercial-scale facilities. Climeworks is also optimistic it can reduce its costs in coming years; it has already sold some of its directly captured CO2 to Coca-Cola. Plenty of sceptics argue that this is all the rhetoric of start-ups looking for investment, but the estimates are backed by peer reviewed studies that have seen the expected cost of direct air carbon capture plummet as the technologies have developed (Service, 2018).
It’s also possible for governments to tip the scales. Currently, leading nations subsidise the fossil fuel industry, particularly in the United States, through direct and indirect tax breaks. There is vast potential for these resources to be redirected in a less destructive fashion, backed up by policy and regulation. Supporting carbon capture and utilisation in these ways could not only roll back ongoing environmental damage but open up new opportunities for resource-poor regions of the world.
To scale up this technology, governments worldwide need to continue to build the market for carbon. Putting a price on carbon dioxide pollution will encourage the industry to grow and mature as it provides not only a valuable commodity, but also a service to companies and individuals seeking to comply with either government policies or a sense of responsibility to offset their carbon footprint.
This situation is akin to the early days of the wind and solar power industries, which started off impractical and expensive but blossomed with investments and incentives from governments. Large governments can be motivated to support the technology in order to keep up with their Paris Agreement pledges to offset or reduce emissions, while smaller nations may see it as an opportunity to sell a new natural resource that can be extracted literally anywhere on the planet.
According to data from the World Bank, as of February 1, 2019, only 13.8 per cent of annual global greenhouse gas emissions are subject to some sort of carbon pricing scheme. Initiatives scheduled to launch in China, South Africa and Canada’s Prince Edward Island will increase that percentage to nearly one-fifth of all emissions. Several other large economies, including Brazil, Japan, Mexico, Thailand and Vietnam are also considering similar programmes.
Extracting and using atmospheric carbon dioxide is not the only answer to our climate crisis.
This leaves plenty of room for growth. Not all emissions are taxed or taxed adequately (Naims, 2016) even in countries with programmes, and some of the biggest polluters – including India, Russia and Indonesia – are largely on the sidelines. The most obvious bystander is the United States, whose outsized carbon footprint makes it key. Despite the Trump administration’s intention to leave the Paris agreement, there is nonetheless progress being made on the American front. For example, California, which is responsible for about one per cent of global emissions, has set a goal to use only carbon-free electricity by 2045 and subsequently go carbon negative.
Last year a study in Environmental Research Letters (Minx, 2018) reviewed the state of “negative emission technologies” (NETs) worldwide, including carbon dioxide utilisation. It estimated that capturing carbon from smokestacks and directly from the air, then either storing it underground or converting it to useful fuels, materials and other resources could extract up to 10 billion metric tons a year. However, that’s looking at the market and technology as it stands right now. Capturing carbon and putting it to use is, at least in principle, limitless: other approaches like reforestation, trapping CO2 in soil, weathered rocks and even pumping it directly underground have sharp practical limitations.
Extracting and using atmospheric carbon dioxide is not the only, and certainly not the complete answer to our climate crisis. But it could prove to be one of the answers we can’t do without.
Eric Mack is a writer, radio producer and podcaster based in Taos, New Mexico. He is a contributing editor for @CNET, @ourwarmregards producer and regular contributor to @Forbes and @Inc. For the past two decades he has been reporting on climate change, and efforts to stem it and adapt to its impacts.
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