But let us think beyond these fossil fuels for a bit. Carbon capture and sequestration technology can, in fact, be used for all sorts of other things. For instance, it can be employed to curb emissions from heavy industry by attaching it to boilers and blast furnaces, steel mills, cement plants, and so on. I wouldn’t be the first one to argue that CCS needs to be reconceptualized, and that advocates would have more success if they rebranded the technology to emphasize biomass, gas-fired power, or industrial uses.19 We even see the IEA experimenting with these foci. The nonprofit Carbon180 talks about “renewable CCS,” distinguished by two key features: (1) renewable systems that capture from an atmospheric CO2 source (as in BECCS), or direct air capture from ambient air (as opposed to a fossil source); (2) long-term storage, rather than capture for short-lived fuel or chemical production. What you get, then, is not primarily an energy generation technology, but a pollution disposal technology.
There is an opportunity here to appropriate this group of techniques for redistributive ends. Morally, rich countries have an imperative to develop this technology, and use it, in order to reduce climate risk for everyone. This comes down to having an appetite for paying for and living with expensive infrastructure—and for making bright, clear distinctions regarding how and why it is built.
Reconceptualizing CCS is not going to be easy—especially given that the latest concept to gain traction is using CCS to produce low-carbon or carbon-negative oil. Essentially, enhanced oil recovery works by using water or carbon dioxide to flush additional oil from used-up wells. The industry has been doing this for decades, but now, there’s a climate policy rationale for it. The key limitation to enhanced oil recovery, for the time being, is the low supply of carbon dioxide; most of the carbon dioxide the companies used is mined from caverns in Colorado and piped over to oil fields in the Permian Basin, in Texas. Installing CCS at ethanol plants instead, or building direct air capture facilities, could supply this demand for CO2—and potentially more cheaply, especially if states like California certify the oil that is produced as lower carbon. Hence, a few industrial actors are promoting CO2 EOR in residual oil zones as a “negative emissions” technology. In fact, direct air capture company Carbon Engineering announced a partnership with a subsidiary of oil company Occidental to build the world’s largest direct air capture facility in Texas’s Permian Basin, initially to capture 500 kilotons of CO2 per year—to supply enhanced oil recovery operations, in a move touted as opening a pathway for carbon-negative fuels. Whether those carbon-negative fuels will ever be delivered is debatable, since they would only be carbon-negative under a particular life cycle accounting. It’s easy to see how this maneuver could reassure nervous investors that there might be a continuing future for oil, and incentivize further oil production, while never delivering on the “carbon-negative” part of it.
Yet direct air capture technology need not be simply a tool of oil companies. The basic underlying technology could offer an opportunity to break the psychic chains between CCS and fossil fuels—depending upon who develops and controls it.
Mining the air
The idea behind direct air capture is simple. Instead of capturing carbon from a concentrated source like a power plant, or a cement factory, just capture it directly from the air. A handful of companies have working pilot projects that are doing this, using the captured carbon in greenhouses or to produce transportation fuels. Swiss company Climeworks has even partnered with a subsidiary of Coca-Cola to use its capture carbon in beverages. Yet direct air capture is expensive at present, in terms of both energy and money.
To understand the landscape for this emergent idea, I talked with Klaus Lackner, an engineering professor at Arizona State University and director the Center for Negative Carbon Emissions. He has been working for decades on direct air capture, approaching it as a waste management problem. Fossil fuel emissions are a cumulative problem, he underscores: the more you put out, the worse it gets. “See, we are actually all are incorrectly trained, and I actually don’t know how that happened. It is in itself an interesting question,” he muses, explaining that sulfur pollution and acid rain in the 1970s and 1980s effectively trained us that pollution has a lifespan in the atmosphere, and then goes away. CO2, however, truly accumulates. “And it actually does change the way you think about the problem. You see immediately, if I pretend garbage is CO2, right?” You wouldn’t allow people to throw waste in the street, he says, and you wouldn’t accept it if someone claimed they were just dumping 10 percent less garbage than last year. We can’t afford to dump CO2 in the atmosphere, he says, yet we have been. “But now the litter is so, so big that even if we stopped emitting tomorrow, we have to come back down. So we need carbon removal technologies.”
What exactly is he building? Picture a machine the size of a shipping container—each one removes a ton of CO2 per day, and you could deploy four of these on a square kilometer. Sequestering 4 million tons per year on that square kilometer would be like erasing the emissions of half of a big coal plant. These machines would be mass produced, and situated in places where you’d want to collect and store CO2. They would provide a service—the cleanup of pollution that was ignored in the past—much as the engineers who maintain an urban sewer system provide a valuable service.
One engineering challenge is that carbon is dilute: 400 (plus) parts per million. Lackner suggests thinking of windmills as miners that pull kinetic energy out of the air. With direct air capture, pulling the CO2 out of the air is like mining it. If it’s mined for disposal, perhaps all he gets is a tipping fee, a fee for the waste disposal—say thirty dollars a ton. “So now I can say, ‘Okay. I have a cubic kilometer of air.’ Which sounds huge, but it turns out a big windmill sees this in an afternoon. You can ask, ‘How much kinetic energy is there?’ Turns out, it’s $300 worth. If you ask how much CO2 is there, turns out it’s $21,000 worth.” Even though CO2 is dilute, it’s relative—the CO2, by this measure, is seventy times as concentrated as wind energy.
And, he adds, the geographic footprint would be smaller than that of wind energy, especially if you wanted to fill a single drill-hole with carbon. “You could think of these things sitting around in corners of a field. You could see them in corners of a wind farm. And they are actually smaller in the wind farm. Or solar panels.” They could absorb excess capacity when supply of renewables is higher than demand. Imagine looking at it from an airplane: most of what would be visible is simply solar panels. “You see these solar panels there; there’s this one curious thing in the corner, which is there to collect the CO2.” The footprint might be physically smaller than the renewable energy sector, but the revenue might be comparable.
In this scenario, scaling up direct air capture sounds much like the scale-up of renewables: rural and remote communities are asked to bear the burden, with some possible benefits. I wonder if there’s any way to make the infrastructure more lively or beautiful—the devices have been referred to in the press as “artificial trees.” Is it actually possible to actually design air capture devices that look like trees, I ask? He says that it is possible, but his team is probably not the right group to do so—and gives an explanation involving a membrane and the difficulty of making a flat sheet of his material (because it expands when it gets wet). The main design consideration, though, is to site direct air capture where you want to store the CO2.
“The architecture group here wants to do fancy things on the outside of houses and buildings. And they say, ‘Well the wind blows by there, why don’t we just collect CO2 while we go? And being in Phoenix we can use them as shade structures at the same time.’ Then, well, now you have ten tons of CO2 at the end of the day out of your building; what are you going to do with that? Right? I need to be somewhere where I can make use of that CO2. So I think a lot of them will be like your mirrors in the desert, like your windmill farms in Kansas. And they will just be out of sight for most of the population. I think that’s actually very likely. And not only because we want to hid
e them, but also because most of the places where you really could do something with that CO2 are not under cities. For one thing, people don’t want to live right on top of the CO2 you just put away. And this gives you the flexibility, right?” Lackner notes that this would inherently be a very big industry. If you could do it for thirty dollars a ton, which he names as an ambitious target for the long term, you’d need a trillion-dollar-per-year industry to pull as much CO2 out as we are currently emitting, meaning that it would take us forty years to pull back one hundred parts per million. But, he adds, it would also be an industry with a known sunset, because we wouldn’t want to take out, for example, 300 parts per million. “And so, you know at some point that task ends.”
Critics are quick to point out that the thirty-dollar-a-ton target is very aspirational. A 2011 report by the American Physical Society on direct air capture, one that still haunts discussions of the technology, projected it would cost $600 a ton.20 (In fact, this is what it costs a company called Climeworks to do direct air capture at its small demonstration facility in Switzerland, where the CO2 is used in greenhouses for growing things like cucumbers.) Lackner critiques the methodology in this report, though, because it is based on a conceptual device made entirely of off-the-shelf things that we already know how to do, with no attempt to make the process streamlined and efficient. “Once you get on an experience curve and start learning,” he says, “I would have taken those messages as saying, ‘Oh! This is actually a remarkably good start for something!’ We aren’t done yet. Right?” Lackner thinks that bringing the price down by a factor of ten might not be that hard, ticking off examples of technologies that get cheaper over time, especially when using mass production: photovoltaics today are one hundred times cheaper than in the 1960s, and wind energy is about fifty times cheaper.
As of this writing, I think it’s fair to say that we don’t actually know how much it will cost to capture carbon from the air. The system designed by Carbon Engineering, a firm based in British Columbia, reported costs of between $94 and $232 per ton of CO2.21 If costs could be brought down to one hundred dollars per ton, removing five gigatons per year would run about $500 billion, or 0.6 percent of global GDP. (For comparison, the bill for damages from the US hurricane season in 2017 was about half that.) The primary limitation of direct air capture technology is financial—a reflection of people’s willingness to pay to dispose of this waste properly. It’s a social value. “Look at what happened in recycling,” Lackner suggests. “How did people decide that you actually recycle, and not turn around the corner and dump it into the landfill?” People who you can’t convince of the reality of climate change, Lackner observes, can still be convinced to clean up after themselves. He recalls an open house where his team set up a table with Ziploc bags filled with sand: a half pound, a one pound, and a two pounder. They’d ask people how many miles their car gets to the gallon; if it was thirty, for instance, they were handed a one-pound bag of sand, which weighs the same as how much that vehicle emits. “And most people were shocked how much stuff comes out of their car. Because it’s colorless and odorless and not visible. So they don’t appreciate how much it is.”
When we think from this waste management frame, it makes it easy to connect the nascent direct air capture industry to environmental justice concerns. Lackner sees all kinds of regulatory questions that will need to be answered as the industry matures: the definition of a true removal, how to know it was done, how to know it is permanent, and what industry standards should govern it, to name a few. There are safety issues, too: the process needs to be certified as safe and harmless. “This then ties to policy, ties to regulatory frameworks, and ultimately ties to the law. If I’m downwind from a field, can I get sued by a farmer who says his corn didn’t grow as well as before, because I took CO2 away? Nobody has thought about that yet.”
The environmental justice questions aren’t just a matter of avoiding injustice. Could a direct air capture industry could further climate justice? If so, what would it take to accomplish this? I ask Lackner about how his technology could address things like historical responsibility.
“Yeah, you could imagine if you were so inclined … We get started, and because we’re not very good at it, this year we clean up 1800 to 1804, next year we are cleaning up 1804 through 1808. And we keep going along like that, when we hit the 1950s we really have to be big, right? And so, I see the argument India has made, that we should not stop their development.” But as Lackner, notes, we have never been good at reparations. “Think of slavery, think of colonialism. We even refuse to apologize, because it would set precedents. So I have a hard time seeing that the industrialized countries suddenly see the light and turn around and say, ‘Okay, it was all our fault, we will take care of it’ … So I think the outcome is much more likely that we handle it on a per capita basis today.” There’s an argument to be made, though, that carbon removal could be reparative. “If every person on the planet has a carbon budget which includes his ancestors’ carbon budget, then we in the US and in Europe have basically blown our budget a long time ago, I mean. Carbon removal technologies, air capture in particular, would actually allow you to pay it back. So you could negotiate and say, ‘We know that we had a history of it, and we will level the playing field.’ You could, in principle, say that. Am I an optimist that we will say that? No.”
But Lackner is more optimistic that we can learn to see this as a waste management problem. “We have taught people about recycling. We have taught people about renewable energy. And there we were actually extremely successful.” He suggests that if there were a certification system that was trustworthy, people might be convinced to pay a little extra for carbon removal. If you could convince Amazon, for example, to send its customers a pop-up at the moment of payment that says: “‘Your CO2 bill would be fifty cents. Are you willing to pay that?’ And I’m sure I would say yes, if I trust the system is actually doing it.” Just like recycling, Lackner thinks, it will start with a few standalone adopters and volunteers who feel strongly about it. “At some point, politicians say: ‘And now it’s regulated. You don’t have a choice in the matter anymore. If you want to buy a gallon of gasoline, twenty pounds of CO2 have to be put away.’ And then you could also have volunteers who say, ‘I’ll take my grandfather’s CO2 back.’”
Lackner is clear to say that at the end of the day, he can’t guarantee that this technology will work. “I think it would work, but until it really works, I can’t guarantee it. I am the first person to agree that we shouldn’t take it as a fact that we can do it, and therefore that we have nothing to worry about. But I can tell you that if it fails to mature in our lives—because we have not worked on that, or maybe because we couldn’t make it work—then there will be a high price to pay for that. Because we will overshoot, and if we can’t come back down, we will suffer all the consequences. If we can come back down, the consequences will be less.”
Taking CCS to the next level
What are the costs of failing to understand CCS through the right frame? Without active engagement from climate justice advocates, CCS probably won’t go in the right direction, and an opportunity for climate repair will be missed.
Direct air capture can be applied to carbon removal in two fundamental ways—what I’m calling the two levels of carbon removal, where the first level involves million-ton scales and the second level involves billion-ton, climate-significant scales. On the first level, direct air capture could be used for so-called “carbon capture and utilization,” or CCU: niche applications in the “carbon to value” economy, or carbontech sector. A lot of this is basically what I’d call concept art, where the value is getting people to think differently about carbon: Did you know you can make shoes out of carbon dioxide? Indeed, materials scientists have discovered all kinds of things you can make with captured carbon dioxide, from makeup to carbon fiber. Some people working in climate policy see CCU as a step stool from level one to level two. Much like with enhanced oil re
covery, the idea is that it provides an initial market to develop the technologies and bring their cost down. One consortium trying to bolster the carbontech sector, the Global CO2 Initiative, claims that the CCU sector could reduce emissions 10 percent by 2030, identifying four major markets: building materials, chemical intermediates (e.g., methanol, formic acid, syngas), fuels (methane), and polymers.22 This might actually be true, if you were to count the emissions displaced by the decarbonization of concrete manufacturing; cement production, it turns out, is responsible for some 8 percent of global emissions.23 Indeed if cement were a country, only China and the United States would emit more. so decarbonizing concrete is promising. And air-to-fuels, as mentioned earlier, hold huge potential as a use product for the captured carbon. But again, avoided emissions are not the same as negative emissions or carbon storage.
However, this scale of projects is vastly different than Level 2 carbon removals: removals that would affect the climate and actually draw down greenhouse gas concentrations in a noticeable way. The key limitation of turning carbon into valuable products is the staggering scale of current emissions—so much carbon is emitted that we’d only be able to use a tiny fraction of it. A 2017 study in Nature Climate Change examines the potential contribution of CCU to climate goals. The authors find that “CO2 utilization is highly unlikely to ever be a realistic alternative to long-term, secure, geological sequestration,” and that it could comprise only about 1 percent of the mitigation challenge.24 Another issue is that a lot of the products release the carbon again at the end of their lifespan. If carbon is turned into urea and used as a fertilizer, or turned to methanol for fuel, it’s only utilized for some months. The authors strongly emphasize the danger of reinforcing the narrative that CO2 utilization is key to CCS. “If this narrative continues,” they warn, “it introduces the very real risk that emission mitigation targets will not be met and that CCS through geological storage will not be deployed in any meaningful way.”25
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