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Transcript for Season 5, Episode 6: Can We Pull Carbon Out of the Air?
HOST: So far this season, we’ve been looking at some of the technologies we’ll be relying on to meet our climate goals. Things like solar arrays, better batteries for electric cars, and nuclear power. Each of these comes with its own sets of challenges, but also, proponents who believe that — with the right support — they’ll be critical players in the push to lower carbon emissions.
[THEME IN]
HOST: And on that front, we’re making progress. In 2015, forecasters predicted that global warming emissions would rise by about 16 percent by 2030. Now, we’re on track for a three percent rise in emissions. That's much lower, and genuinely good news.
But here’s the challenge: the Paris climate agreement says we need to reach net zero by 2050. And even the most aggressive plans to curb emissions still anticipate burning some fossil fuels well past 2050. So how do we square that? For every ounce of CO2 we put into the atmosphere, we’ll have to pull an ounce out. It's a math problem. A big one.
This is where Direct Air Capture, or DAC, comes in. Direct Air Capture is a process that, essentially, pulls carbon dioxide out of the air. The hope is that it could offset any CO2 we continue to add to the atmosphere. And ultimately, once we stop burning fossil fuels, it could help bring the total amount down.
But Direct Air Capture has its own challenges. It has yet to prove itself on a large scale. It requires an enormous amount of energy. And once the carbon dioxide is removed from the atmosphere, it has to be transported and stored safely somewhere.
All of which is to say, there are more unknowns here than with some of the other technologies we’ve talked about this season. Is Direct Air Capture the final runner in a relay race that will get us over the finish line? Or is it an expensive distraction that will knock us off course?
I’m Arielle Duhaime-Ross and this is The World As You’ll Know It.
[THEME MUSIC OUT]
HOST: Some people call Dr. Klaus Lackner “the godfather of carbon removal.” Other people just call him grandfather.
Arielle Duhaime-Ross: I hear that you're being a little bit of, you know, Grandpa Klaus right now, is that correct? You have some grandkids around you.
Dr. Klaus Lackner: Yes, Opa. [chuckles] They may have just left for a walk. [chuckle]
HOST: Lackner is a professor at Arizona State University where he founded the Center for Negative Carbon Emissions. He started his career in particle physics and worked for years at Los Alamos — a hub for American nuclear research. He was researching nuclear fusion when he began thinking about the math problem posed by climate change.
Dr. Klaus Lackner: So I realized in the early 90s that the world needs plenty of energy, but the way it generates energy today from fossil fuels is fundamentally unsustainable. And so it was very clear early back then that we have plenty of fossil carbon. And the real problem is not that we ran out of fossil fuel, but that the damage we can do with the CO2 we pile up in the atmosphere is just not tolerable. So you have on the one side the environmentalists who say we need to stop using fossil fuels because it's bad and it causes damage. And you have on the other side, people who say, “but we want our energy”. And in a way, the economic impact of pulling 85% of the energy supply out from under you is horrific. And it is not just horrific for us. It's really, really bad for developing countries. And so that then naturally led to the question, “Can I actually pull the CO2 back out of the atmosphere?”
[MUSIC IN]
HOST: In the 1970s, oil and gas companies started collecting some of the carbon dioxide produced as a byproduct of oil drilling. They figured out that if they injected CO2 back into the ground it would loosen more oil, making wells more productive. Twenty some years later, Lackner wondered: “what if you could use this same concept to remove atmospheric carbon - permanently?”
Dr. Klaus Lackner: And so I said, well, we ought to be able to build something akin to a tree or a windmill that scrubs the CO2 out of the wind and then removes it, just like the windmill scrubs out the kinetic energy and then converts it to electricity. And so that's how that started.
Arielle Duhaime-Ross: When you proposed removing carbon from the atmosphere back in the late 1990s, what responses did you get from the scientific community?
Dr. Klaus Lackner: Well, mainly, “This is too difficult. This can't be done.”
Arielle Duhaime-Ross: So a lot of negativity. People were thinking, “mmm this is impossible.”
Dr. Klaus Lackner: Right. And that can't possibly be true, because the tree apparently can do it. So if it were thermodynamically impossible, the tree couldn't do it either. So, there are natural analogs which work.
[MUSIC OUT]
HOST: In 2007, Lackner and a company called Global Research Technologies, successfully demonstrated Direct Air Capture for the first time. Their prototype was basically a tall air filter. It was this big column outfitted with a scrubber that captured carbon dioxide.
17 years ago the prototype showed the world what was possible. And yet today, only a handful of companies around the world are attempting to do this commercially. Meanwhile, the need for this technology keeps growing.
Arielle Duhaime-Ross: Back in the 90s, how much carbon did you think we'd need to remove from the atmosphere every year? And I mean like back then.
Dr. Klaus Lackner: [chuckles] Back then I would have said six gigatonnes of carbon. Because that's what we were putting out.
HOST: Quick note, a gigatonne is a billion metric tonnes.
Arielle Duhaime-Ross: How about now?
Dr. Klaus Lackner: [chuckle] Now I would say ten gigatonnes of carbon because that's what we are putting out.
Arielle Duhaime-Ross: Okay. So huge change. A lot of people talk about the year 2050. How much carbon do you think we'll need to remove annually by 2050?
Dr. Klaus Lackner: That's very hard to predict. If we really wanted to solve the problem and stay where we are, right now, this is 40 gigatons a year.
HOST: Until recently, we’ve only had capacity to remove around 10,000 metric tonnes of carbon per year from the atmosphere using Direct Air Capture. Meanwhile humans released 37.4 billion tonnes of CO2 just last year. So, currently at least, we’re barely making a dent.
[MUSIC IN]
HOST: But things could soon scale up. A Swiss company called Climeworks has just opened a DAC facility in Iceland that, it claims, will be able to remove up to 36,000 tonnes of carbon per year.
The international energy agency projects that, if all currently planned projects move forward, Direct Air Capture might help us remove as much as 3 million tonnes of carbon per year by 2030.
Once the carbon dioxide comes out of the air, though, you have to do something with it. That's the other side of the equation.
Arielle Duhaime-Ross: Are you actively working on storing carbon dioxide, you know, underground at the moment?
Dr. Susan Hovorka: Yes. I think it says on my resume, “My little sticky fingers have been on 11 million tonnes stored.” That's my headcount. Several of the projects that we worked on getting commercialized are running splendidly at a rate of two or three million tonnes a year.
HOST: This is Dr. Susan Hovorka. She's a geologist at the University of Texas at Austin. She’s been working on carbon storage for the past 25 years.
Dr. Susan Hovorka: There's enough storage to do the deed. We have lots of storage in the subsurface. We have techniques in our kit, and I've personally been to the field eight times with big teams to make measurements to see if, “are the techniques robust? Can we trust them?” The answer is yes, they are. Actually, if I could have proved that it was not going to work, I could have written more important papers. [chuckle]
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HOST: Hovorka and her team are experts in storing carbon. They focus on how to get CO2 into the ground, for good, using a method that’s getting a lot of attention: gas or liquid injection.
The way it works is by pumping CO2 underground and allowing it to penetrate the pores of rocks deep below the surface. Hovorka and her team have been injecting and storing carbon underground, using old oil wells, since 2004.
Dr. Susan Hovorka: So in 2004, I had just less than $5 million funding for a team to work on the very first U.S. deep saline formation injection, which we did in Dayton, Texas, which is just outside of Houston, not very far from the airport. Which is a residential area. People live there. We had a partner who was willing to let us use existing wells that had produced oil, but we used a zone that had no oil in it.
So what we did is we brought about a hundred truckloads of CO2 that usually goes to a beer operation. So the truck drivers were surprised to drive it out in the woods [laugh] and we offload it into a tank and we injected the CO2 into the well, and we made thousands of observations of what happened. And the interesting thing is, at the surface, nothing happens. The researchers sit there under the canopy, collecting their fluids and watching their instruments and so forth. Everything is happening a mile deep. The surface activities go on as normal.
HOST: One of the major concerns with this process is leaks. What happens if carbon dioxide leaks out of those wells and reaches the surface?
Dr. Susan Hovorka: The regulations are very strict. I, myself, and our team have looked at some 800 wells in West Texas that have been operating since the 70s in CO2. We were sure we would find some – we couldn't find any. [laughs]
Arielle Duhaime-Ross: You couldn't find any leaks?
Dr. Susan Hovorka: Any that are leaking CO2. We thought we were so clever. It would have been a much stronger publication and more prestigious for us to find two or three that were leaking. We thought we had one in Mississippi, and it turned out that it was — the CO2 was modern. The CO2 that was leaking underneath it was not coming from depth. It was modern CO2 from nearby swamps.
[MUSIC IN]
HOST: So, carbon storage, like Direct Air Capture, can work. These methods are technically possible. But to go from that, to saying that we definitely know how to use these techniques to reach our goals, well there’s more to that than just technology. There’s the economics, of course. And the politics. For that, we turn to Dr. Emily Grubert.
Dr. Emily Grubert: I feel like I spend a lot of my time trying to distinguish on all of the decarbonization and energy systems stuff, what's physically impossible, what's currently institutionally impossible, and what's currently politically impossible. And those are very, very different kinds of constraints.
HOST: Grubert is a civil engineer and an environmental sociologist at the University of Notre Dame. She's also a former deputy assistant secretary in the Department of Energy’s Office of Carbon Management. Her work focuses on incorporating the perspectives and priorities of communities into energy policy.
Dr. Emily Grubert: I'm trained in a lot of like pollution management kinds of things. When you go through civil and environmental engineering courses, a lot of it is, you know, how do you get contaminants out of water or how do you get contaminants out of the air? So the notion that you might be able to do something was not — I don't know, it didn't seem like an impossible task to me. I think the thing that I still think about is like, “Oh, that's going to take a lot of energy.”
HOST: Direct Air Capture is incredibly energy intensive. In 2020, Key Numbers, an energy analysis company, calculated that were we to use DAC to remove the net carbon added to the atmosphere that year, it would have required five times the amount of electricity consumed worldwide.
Dr. Emily Grubert: You're also saying, I'm going to use some amount of energy resource to do this instead of doing something else. And we have this tendency to talk about renewable energy as infinite. The renewable energy is basically inexhaustible from a human perspective, but our capacity to harness it using machines and land and all those kinds of things is not.
HOST: It’s worth asking which sources of energy we’ll turn to make up for what’s being diverted to carbon removal. Because if it’s fossil fuels, we’ll be running in circles.
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HOST: Plus, this is going to require a lot of money. Right now, companies like Meta and Amazon are helping fund Direct Air Capture projects by buying carbon credits. These credits essentially pay to have carbon captured and stored. It’s a way for companies to offset their own emissions. Individual people have also purchased these kinds of credits.
Dr. Emily Grubert: Full disclosure, I've been a voluntary purchaser of Direct Air Capture with storage credits from Climeworks since basically the beginning. I want to say that was Fall 2019 for my subscription. So the contract is written in a way that says, basically, we'll deliver what you purchased within a few years. Um, just because when I actually subscribed to them their plant wasn't open yet.
HOST: Climeworks is one of only a handful of companies in the world actively removing carbon from the air through Direct Air Capture. It's been slow going. So the U.S. government has introduced incentives to get more of these projects off the ground.
Dr. Emily Grubert: Under the Inflation Reduction Act, basically the existing tax credit for CO2 storage is just how many tonnes of CO2 did you put underground.
HOST: Under the IRA, every tonne of CO2 pulled out of the atmosphere through Direct Air Capture and then stored permanently underground is eligible for a $180 tax credit. But the cost of removing and storing carbon runs about 600 to 1,000 dollars per tonne.
Dr. Emily Grubert: So 180 is not a huge percentage of 600 or 1,000, if you're thinking about this as the thing that's going to encourage people to do this. The other piece of this CDR is not required anywhere by anything.
HOST: A quick note here, “CDR” is short for “carbon dioxide removal,” it’s a sort of catch-all term for the various ways to capture carbon emissions.
Dr. Emily Grubert: So this is entirely voluntary and there's a little bit of a subsidy, but you need to come up with a huge amount of other money in order to make this work.
HOST: Grubert sees this as one of the core problems with Direct Air Capture in the U.S.
She believes that if we’re going to use this technology, it should be used surgically, to compensate for the emissions of industries, and possibly countries, that simply can’t decarbonize overnight.
[MUSIC IN]
HOST: Her argument is that companies which have the resources to fund fossil-fuel alternatives that could power their server farms, those companies could and should do so, rather than buying the limited offsets available.
The problem, as she sees it, is that many of the companies large enough to pay the current going rate for Direct Air Capture credits are companies that could also afford to decarbonize.
Dr. Emily Grubert: This is maybe my spicier take on this is, [chuckle] I think the way that it's set up right now is basically appropriating a very, very scarce resource for whatever we want. And so, like, if I buy a tonne of carbon dioxide removal and I decide that I want to use that to go, like, I don't know, do burnouts in a parking lot, I have just said, “I'm going to take one of the 4000 tonnes of CO2 removal that the world has this year and dedicate it to, like this frivolous activity that I've decided I want to do.” And that's really different from having a situation that says, “wait, okay, like this is the minimum amount that we need, this is why we need it, and this is how we're going to match it up to the things that we know we're going to have a harder time mitigating.”
Arielle Duhaime-Ross: This burnouts in a parking lot example, is this a real example?
Dr. Emily Grubert: No, unfortunately. [laughs]
Arielle Duhaime-Ross: [chuckles] Okay, okay. Just wondering.
HOST: There's another factor to consider with this technology. One which, for some people, presents an uncomfortable situation. Some of the biggest investors in Direct Air Capture, so far, are oil and gas manufacturers. One of the two major Direct Air Capture hubs to receive federal funding last year is owned by a subsidiary of Occidental Petroleum.
And, the CEO of Occidental has said the technology will give the industry quote “a license to continue to operate for the next 60, 70, 80 years.”
I asked Hovorka about the role fossil fuel companies have played in Direct Air Capture so far.
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Arielle Duhaime-Ross: From what I understand, some oil and gas companies have actually funded some of your work.
Dr. Susan Hovorka: Oh yeah.
Arielle Duhaime-Ross: What's in it for them? Why do you think they're doing that?
Dr. Susan Hovorka: [chuckle] Two things. They're interested in profit, and they have a lot of skills handling fluids in the subsurface. So all these major energy companies see it as a future business. They're seeing potential or certainty of decline in their and their fossil business.
Arielle Duhaime-Ross: Mmhmm.
Dr. Susan Hovorka: What are they going to do next? So abate everyone's carbon is an attraction that uses their — repurpose their skills. So some people don't like it because it uses the classic skills of oil and gas companies.
Arielle Duhaime-Ross: But what would you say to someone who's upset about oil and gas companies then being able to profit from this kind of technology?
Dr. Susan Hovorka: Climate is such a serious problem. I don't actually care who profits as long as we get there. They have the expertise to do the project safely. So you probably actually want them, even though you're not a fan of petroleum itself. You need the expertise.
HOST: I put this to Klaus Lackner as well.
Arielle Duhaime-Ross: You're a scientist. You've been doing this a long time, and you've seen how money and markets can influence how ideas are implemented. And now we can see the parties that are most interested in Direct Air Capture. Right? It's a lot of private industry, tech companies, uh, oil companies. I wonder how you feel about those groups being the ones that are championing this kind of work.
Dr. Klaus Lackner: I'm not sure they are in the long run, the champions. I, I think – taking my view that the fossil fuel companies are liable for the carbon and therefore need to do it, I actually am not opposed to the fact that they show up at the party.
Arielle Duhaime-Ross: Mmmm
Dr. Klaus Lackner: Right. If they are liable for it they should. Particularly if you talk about geological sequestration, they have an awful lot of expertise.
Arielle Duhaime-Ross: Right.
Dr. Klaus Lackner: And so having somebody with expertise coming to the table and saying, “I know how to do that” is also very useful. The skepticism I have is that they will always think of this as a drag at the bottom line, and they will be pulled into this kicking and screaming.
HOST: Direct Air Capture will likely become cheaper over time. But each of today’s guests argue that DAC will only become economically feasible when we start to treat carbon the way we treat other waste — you pay to get it removed. Properly and regularly.
Arielle Duhaime-Ross: What needs to be done in order to get the cost of Direct Air Capture and storage down?
Dr. Susan Hovorka: You're not going to get the costs down. You're going to learn to pay for it the same way you pay for having a water treatment or garbage disposal.
Dr. Klaus Lackner: It's just like municipal garbage. It's just like sewage. We have ignored that problem until it hurt. And that was true for sewage. This was true for municipal garbage. And at some point you have to sit back and say, “look, you're not allowed to dump it into the environment. You have to take care of it in an appropriate fashion.”
Arielle Duhaime-Ross: What do you think needs to happen in the next five, ten years for us to be on track to hit our Paris 2050 goals?
Dr. Klaus Lackner: My guess is we will miss them. And we will spend the 60s and 70s cleaning up, and we will have to grow into that. And I think — I would argue the first thing you could do is demand that carbon is cleaned up and then that will lead to reductions in fossil fuels. This will lead to sequestration at an unprecedented scale, and things can happen fast once there's an economic incentive.
Arielle Duhaime-Ross: Right, but you think that it's going to take a while for us to implement that economic incentive globally?
Dr. Klaus Lackner: That is where it is much harder in a way. There's a chicken and egg problem. The technologies will not get better unless they are deployed. And the deployment will not happen unless it is demanded. And the political will to demand it would be a lot easier if it were cheap. When I started out I said, “If the world thinks of the price of carbon removal at $1,000 a tonne, the world will say ‘climate change is a hoax’ until it's too late. If it's $5 a tonne, we would be arguing, ‘Why haven't we done it yet’”
[MUSIC IN]
HOST: We've spent the last six weeks looking at some of the tools and technologies that will be part of the shift from fossil fuels to emissions-free energy sources. These energy sources all have their own trajectories. Some may be wildly successful and others less so. But there’s a bigger story they’re all a part of. Something we might not be able to see from where we’re sitting. And something Richard Rhodes, author of The Making Of The Atomic Bomb, knows well.
Rhodes has studied the history of energy transitions. and we’re in the middle of a massive one right now. So I asked him: “how long do these transitions take? How long before we can expect the world to look truly different, and carbon free?”
Richard Rhodes: It will surprise people, because I think when we think of a new discovery or a new invention in the world of energy technology, we assume that it's so obviously better than what came before that it's going to be immediately installed in place of what came before. But it turns out that transitions on this scale take a long time. I worked with an Italian physicist who has studied at length the actual historical record of energy transitions. He describes a typical transition as taking around 100 years to go from zero penetration of the world market to 50%, in other words, dominance. Now, why? I mean, why should electric cars take as long as they are? Why should anything take as long as it did? And the answer is, we have to learn how to use these systems. We have to build the infrastructure that goes with these systems and is necessary for them to operate. And, in addition, there's another factor, which takes time, and that is the people who have invested in the previous technology are not at all interested in seeing the new technology cause their profound dollar investment to become what's called a sunk cost, meaning wasted, lost to the investor. So for all of these reasons, it takes about 50 years to get to a 10% market penetration, then another 50 years to get to 50%. Now, do we have that time?
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[CREDITS MUSIC IN]
HOST: This was the final episode of season five of The World As You’ll Know It. I'm Arielle Duhaime-Ross. Thank you for listening.
The World As You’ll Know It is brought to you by Aventine, a non-profit research institute creating and sharing work that explores how today’s decisions could affect the future. The views expressed don’t necessarily reflect those of Aventine, its employees or affiliates.
For a transcript of the episode and more resources related to what you've heard in today's episode, please visit Aventine.org/podcast.
Danielle Mattoon is the executive director of Aventine. Bruce Headlam is the editorial director at Aventine.
This episode was produced by Elliot Adler with support from Alexis Moore, Lisa Cerda, and me, Arielle Duhaime-Ross. Additional writing and producing from Bruce Headlam. Our editor is Eric Mennel. Kamilah Kashanie is our managing producer.
Original music by Vera Weber and Davy Sumner, with additional music from Epidemic Sound.
This episode was mixed by Marina Paiz.
Our recording engineers are Pedro Alvira, Hannis Brown, & Davy Sumner. Additional support from Sharon Bardales and Jade Brooks.
Research and fact checking by Will Tavlin. Creative direction and design by Curt Courtenay and Lauren Viera.
Music licensing by Extreme Music and Epidemic Sounds.
Our Executive Producer is Je-Anne Berry.
Special Thanks to Emerald O’Brien and Xandra Ellin.
I'm your host, Arielle Duhaime-Ross.
Make sure to listen to us on the Audacy app or wherever you get your podcasts.