This is the second installment of our Climate Interventions series, where we look at the scientific understanding and uncertainties around a range of interventions to reduce greenhouse gas emissions and cool the planet, along with a robust discussion on ethics, risks, and governance.  

From nature-based to technological solutions, carbon dioxide removal could help address the root cause of climate change by cleaning up Earth’s atmosphere. Exploring removing carbon at scale means examining the environmental, economic, and social benefits and tradeoffs. This panel discussion explores issues of verification, ethics, and community engagement on an array of solutions that exist across broad geographic scales.  

Featuring: Wil Burns, Co-Director, Institute for Responsible Carbon Removal, American University and Visiting Professor, Environmental Policy & Culture Program, Northwestern University; Freya Chay, Program Lead, CarbonPlan; Alicia Karspeck, Co-Founder & Chief Technology Officer, [C]Worthy; and Celina Scott-Buechler, Senior Resident Fellow for Climate Innovation, Data for Progress.

The discussion is moderated by Kristan Uhlenbrock, Executive Director, of The Institute for Science & Policy. 

Watch a video of this panel discussion on our YouTube channel.



Carbon Dioxide Removal at Scale

KRISTAN UHLENBROCK: It's a beautiful Monday morning here in Denver, Colorado. I'm Kristen Uhlenbrock. I lead our Institute for Science and Policy. We are a project here at the Denver Museum of Nature and Science. And in partnership with Wil sitting down there at the end, from the Institute for Responsible Carbon Removal, we've been bringing you this series on climate interventions. This is part two, where we're going to be talking about carbon dioxide removal (CDR) at scale. Part one was last month, and we talked about solar radiation management. There's a video available if you missed that and you want to watch that. 

We're gonna talk about issues around policy, technology, ethics, uncertainty, and governance. All these sticky questions when we're talking about these issues as a tool and as a pathway as we think about removing carbon dioxide to try to help solve for climate change, which we need to do. We know we're not on the pathways to meet some critical targets and thresholds. So let me introduce this lovely panel sitting up here.  

We have directly here to my right, Freya Chay, Program Lead at Carbon Plan. Carbon Plan is a nonprofit that analyzes climate solutions. It's based on the best available science and data. Next to Freya is Alicia Karspeck. Her and I worked together many years ago at NCAR/UCAR, but now she's the co-founder and chief technology officer for [C]Worthy, which is a nonprofit that builds software that supports multi scale oceanographic modeling and data integration for quantifying the efficacy and ecological impacts of ocean-based CDR. We have Celina Scott-Buechler. She's finishing her joint Ph. D. J. D. right now at Stanford, while also working full time, and she's had an amazing career thus far. She's a Senior Resident Fellow for Climate Innovation for Data for Progress, a think tank and polling firm. And last but not least is my colleague sitting down there at the end, Wil Burns. Wil is a leader in the carbon dioxide removal conversations and space, and he's been partnering with me to help bring this series together. He's the co-director of the Institute for Responsible Carbon Removal, located at American University and he’s also as a visiting professor at Northwestern right now. 

Wil, start off the conversation by explaining for us why we do CDR. Why?  

WIL BURNS: I see there to be four potential rationale for why we would try to remove carbon dioxide from the atmosphere. The first of them is in the short term - we're trying to buy time while we decarbonize the world's economy. We know that as concentrations of CO2 grow in the atmosphere, temperatures increase. And one of the things that we're worried about is passing critical thresholds. One point five degrees Celsius, two degrees Celsius [above average] is where we start to see serious impacts and, in some cases, potentially irreversible impacts. If we can draw some carbon dioxide out of the atmosphere as we simultaneously work to reduce our emissions, we may be able to extend the period that we have before we pass those critical thresholds.  

The medium-term objective is by the time we get to the middle of the century, the primary international climate agreement, the Paris Agreement, says that we should be aiming for what we call net zero emissions, right? 

Which is to balance what residual emissions we have at that point with things that take carbon dioxide out of the air and get to net zero. To do that, we're likely to need substantial amounts of carbon removal because we're likely even in that time still to have large amounts of emissions from sectors that are hard to reduce emissions in such as aviation, steel, and concrete. 

In the longer term, a lot of scientists believe that we don't want to leave concentrations of greenhouse gases in the atmosphere where they are now past 420 parts per million, that we ultimately want to return to a time where the climate was deemed to be safer, perhaps 350 parts per million, 300 parts per million. What we want to do is continue to work to draw CO2 out of the atmosphere at that point in what's called a net negative scenario.  

Then the last rationale is what we call the overshoot scenario. Let's say we don't meet our temperature targets - we're going to start seeing serious negative manifestations from that. We can use carbon removal to draw ourselves down back below those temperature thresholds. It doesn't mean we won't see serious and maybe irreversible impacts, but we may be able to ameliorate the long term impacts that would occur if temperatures stayed at those levels for centuries beyond this. 

KRISTAN: Any other reasons from the panelists for why we should be doing this?  

FREYA CHAY: I love that framing of the different roles and would also offer just the simplest boiled down version, which is because carbon dioxide stays in the atmosphere essentially forever when we emit it. To stabilize temperatures globally, to stop warming, any carbon we put in, we have to take back out. 

ALICIA KARSPECK: I'll add one point to this, which is really about not just why do we do CDR, but why do we need to do it right now? And that has to do with, that the act of doing carbon dioxide removal is essentially, in a lot of cases, an industrial process, or process that involves engineering and research. So there's a lot of urgency just to start learning how to do carbon dioxide removal at scale now, even if we don't expect to actually do large scale deployment for many years.  

KRISTAN: Alicia, could you talk to us about some of these major pathways? We're going to talk about what are even talking about here when we talk about carbon dioxide removal.  

ALICIA: So a lot of times when we talk about carbon dioxide removal, there's a lot of sort of abstraction. Like, what exactly is this? And what are we talking about? So you'll hear this term pathways come up quite a bit in this discussion and all that really means is the different types of methodologies that we think of to actually remove carbon dioxide from the atmosphere. (Slide 1) 


I want to show you just a couple of the different taxonomies or categories of types of carbon dioxide removal. There's a broad range. The two ones that you'll hear a lot is one called conventional carbon dioxide removal. These are the types of carbon dioxide removals that are currently enacted right now. A couple examples of this are aforestation and reforestation processes or having soil carbon being stored through improved agricultural processes. What we see is that globally, there's about two gigatons of carbon removal that are happening right now through those conventional methods. 

A gigaton is a billion tons. When Wil was talking about our targets for midcentury, that's around 10 gigatons, so we're not where we need to be right now. These conventional CDR methods are really amazing and they're related to the agricultural sector. They do have some challenges, which has to do with this concept of durability, which means that it's not clear how long that carbon remains stored and away from the atmosphere.  

There is another whole class that's called novel or durable carbon dioxide removals. You can think of these as a next generation of types of carbon dioxide removal, which are not as mature in terms of their readiness level. And I'm just going to name a few of them here because the terms will come up. You don't have to remember them all. But just so you're familiar with these terms, you'll hear terms like biochar, which has to do with creating kind of a charcoal-like product that's related to biomass that’s stable. Enhanced rock weathering which has to do with enhancing the natural process of weathering and pulling CO2 out of the atmosphere. We have something called direct air capture (DAC) that's an industrial process where you're removing CO2 directly from the air. You may have heard of ocean or iron fertilization which has to do with this idea that we spur biomass growth in the ocean, and that takes up more CO2.We have things like ocean alkalinity enhancement, and something called direct ocean capture. So, a whole set which we think are very durable, but are actually novel, and we're just working through collectively some of those technologies. 

(Slide 2) I just want to mention a couple of different various taxonomies that people think of. 


So, I just gave you one taxonomy which is conventional versus novel and durable. You'll also hear people talking about these categories of biotic and abiotic. Biotic are any carbon removal processes which in some way evoke kind of natural ecosystems or biological processes - an example of that is ocean iron fertilization. And we have abiotic approaches, which are mostly geochemical. These are things like ocean alkalinity enhancement, enhanced rock weathering, or even direct air capture.  

People often categorize these in terms of natural and technological solutions. I would point out that there's a pretty big gray area. All of these taxonomies are things people are still considering and thinking through. Then, of course, we have this taxonomy of land-based versus ocean-based. These are all ways that people categorize these different pathways. So, to finalize, I want to show you a little bit of what a CDR looks like in practice. (Slide 3) As we'll talk about in a little bit, there's not a lot of CDR going on outside of conventional CDR right now. But we do have some pilot projects for a lot of these different methods. 

I want to show you what this actually looks like in practice. We have actual afforestation and reforestation happening. Agricultural management, that's actively happening right now. There are pilot projects around enhanced rock weathering, which happen on agricultural fields. 

Biochar is a known technology that's happening all the time. What's new is thinking about that in terms of carbon removal. We have new companies working in direct ocean capture, ocean alkalinity enhancement, and this is direct air capture.  

KRISTAN: Thank you, Alicia. Anything else you all would add about the viability and durability of these types of different nature-based and technology-based solutions?  

CELINA SCOTT-BUECHLER: Yeah, I'll start off here. I think we often talk about conventional CDR as ready to go. I want to distinguish between something that we can implement and something that we can do that amounts to measurable carbon removal. I think there's often this idea that we can plant trees and that will count towards CDR. There is the challenge that I'm sure we'll talk about later in this panel of monitoring, reporting and verification. 

I'm a social scientist. I come from a natural science background, but I am now a social scientist. A technology or a pathway is usually thought of as the implementation stage. I want to challenge us - and think that policy in general should be challenged more - to think about a technology or a pathway as start to finish. So, implementation through to crediting.  

Where I slightly disagree with the first figure that was put up on the screen about the state of CDR is that it presents these conventional CDR approaches as ready to go. But they are in a stage of experimentation.  

We need new ways of monitoring how much carbon these new systems are removing. There are questions about additionality, which is to say: how do we know that these actions that we're taking wouldn't have been taken anyway? And how are we contributing to additional tons of carbon dioxide being removed from the atmosphere? 

We'll be talking about scaling CDR. I think of that scaling on the technological front rather than land-based pathways. There's a lot of work to be done to figure out these various pathways, such that they are scalable. Across both categories.  

KRISTAN: Freya, sometimes when people hear “nature-based” they just automatically assume “good,” versus technology. Not saying bad. But when they hear the word “nature,” there's an assumption that there's something good about that. How do you speak about that?  

FREYA: Yeah, it's so interesting. Of the taxonomies that you shared, I find nature-based versus technologically-based one of the least useful. Is speeding up rock weathering less natural than a plantation forest? 

Arguably, no. We are humans intervening in complex systems. The word “nature” carries all this value. But it's not very helpful for us thinking about what makes sense where. One of the more useful taxonomies that I find is the taxonomy around durability. 

So, when you do the action, and it removes carbon, how long do you expect that carbon to be removed? I think that's important for our thinking, based on the science. When we burn CO2, it impacts warming for millennia. 

Forests are fantastic. Soils are fantastic. Removing carbon via these methods does not necessarily mean we are taking care of a fossil emission. Because the liability we have created by burning fossil fuels lasts way longer than we can promise to protect forests or soil carbon. So, I really lean on that durability taxonomy, not to pass a value judgment about what is worth doing or not, but to think about how different technologies or pathways can fit into our big picture climate goals and planning. 

ALICIA: I think that's a great point. I want to add something that may not be clear to everyone here. There is a lot of active academic research happening into all these pathways. 

So, whenever you're hearing terms like “nature-based,” where you're thinking about doing an intervention into the natural system maybe to speed up the natural process of carbon dioxide removal, think about invoking the entire discipline of folks who work in their system science and climate science world already. 

When we think about an ocean-based pathway, we need oceanographers and ocean modelers who are thinking about the ocean carbon cycle and actively enhancing and pushing that research forward. When you think about enhanced rock weathering and soil carbon, we need the entire discipline of folks who work in terrestrial and land modeling, who work in agricultural sciences. 

So just remember, it isn’t just companies pushing this forward. These are not just policy objectives. These are entire groups and disciplines of scientists who are coming along on this journey, helping us understand what it means to do these types of interventions in the natural world. 

KRISTAN: Everything comes with some level of trade off, right? This is the world we live in. Environmental concerns have benefits and trade-offs associated with them. What are some big ones that you’re hearing discussed and debated, researched and evaluated, when it comes to environmental risks and trade-offs? Wil, go ahead.  

WIL: Okay. We've already heard the idea that nature-based is not necessarily an unalloyed good, right? A part of it is the scale that you do it at and where you do it. So, for example, tree planting, which sounds good. We like trees. We reap other benefits from planting trees. 

But when we talk about using afforestation and reforestation at large scales, in terms of carbon removal, we start to get clear trade-offs. For example, many areas where we talk about planting trees are prairie grasslands and savannas. These are areas high in biodiversity, right? 

There could be some clear trade-offs in terms of encroaching in those areas. A lot of times when we talk about tree planting, there are potentially large populations, including indigenous people, that rely on that land for their livelihoods. They potentially could be expelled from that land as elitists in countries try to obtain carbon credits. 

When we plant huge amounts of trees, we can alter the hydrological regime in an area. We can require huge amounts of fertilizer that can result in nitrification. If we plant plantation forests and replace areas where we had a wide diversity of trees, we may undermine biodiversity. I think other speakers will talk about some of the other approaches. But I'd emphasize that nature-based solutions have a role in that goal of getting to 10 billion tons of carbon dioxide removal by the middle of the century, maybe as much as 15 or 20 billion tons at the end of the century if we don't get our act together in terms of decarbonizing. But they must be part of a portfolio. 

Any one of these approaches, at large scale, is likely to prove unsustainable. But figuring out how you cobble all these together and govern them effectively and look at the trade-offs between them is part of the huge social science governance challenge that Celina was talking about. 

CELINA: We’re obviously concerned about carbon dioxide, and for good reason. Carbon dioxide will remain in the atmosphere for millennia. But sometimes, by monetizing that carbon unit, or prioritizing that carbon unit, we are falling into what I like to call carbon dioxide myopia. Which is to say that we're forgetting about other greenhouse gases that might be created in the process of removing carbon dioxide. We might be privileging carbon dioxide removal over the preservation of biodiversity. 

Usually when decision makers - be they private companies or governments - are making these decisions, it's not clear that we're trading off one unit of carbon dioxide for one unit of biodiversity. It’s more like we have one unit of carbon dioxide with maybe a 25 percent risk of some harm to biodiversity. 

And we usually can't narrow it down to 25 percent. It’s within a range. And where these individual actions are making these kinds of risk tradeoffs in isolation of others, we don't have centralized planning around what risks we're willing to take as a society, what risks we're taking in each one of these decisions, and what those risks are cumulatively.  

We are obviously facing a climate crisis. We are also facing a biodiversity crisis. We're also, in many parts of the world, facing equity crises. How do we figure out all of these things together? 

The U. S. is the largest cumulative emitter of carbon dioxide in history, and that creates a responsibility, I think, to remove carbon dioxide. Not only so that we can net out our own emissions, but so that we can contribute to a net negative. That way, the countries and populations that have contributed least to the climate crisis are able to develop in ways that maybe aren't the most sustainable, but that allow them to meet the needs of their populations across some of these other crises that are intersecting with climate. 

At the same time, we face national equity crises. So, it’s one thing to say that the U. S. should take up the mantle of removing excess carbon so that we can be a good global player. But we also need to be thinking about the site impacts of where those projects are going, what communities they're going into, and the kinds of participation and governance processes that we have around global risks and local risks. Is it going to create co-pollutants that affect human health, for example? How do we decide that one community is going to take on that risk burden versus another? I could talk about this for ages, but I'll leave it there. 

KRISTAN: I want to build on that and bring the other panelists into this question from the audience. How do we make decisions around CDR implementation when we know action is needed now, but things are still somewhat experimental with a ton of risks and trade-offs? How do you get past decision-making paralysis? This is not an easy question, I'm sure. But I'd be curious.  

FREYA: I think my litmus test right now is: Does this decision help us learn? If we are setting up a deployment right now that doesn't help us learn and we are taking on these risks, I think it’s probably not worth it. 

So as policy makers, as CDR buyers, whether you're participating in a market, whether you're participating as a regulator, I think the question is: Does this help us learn about what works or doesn't work? Does it get us closer to knowing whether we will have a tool for gigaton-scale carbon removal? 

ALICIA: Okay, so let me disagree. I think we can do a little bit of disagreeing and disagreeing with each other. My perspective is that a lot of the early-stage CDR that's happening, at least outside of the conventional markets, is being done by small scale startups. These are startups which tend to be venture capital backed. Their business models are about trying to remove carbon and then sell onto a voluntary credit market. Celena's been talking about accounting and MRV - the idea of doing enough quantification that you can sell credits on a voluntary carbon market. I think we'll talk about that in a bit. But I'm saying all that to point out that a lot of this early learning is being done by small companies who are probably not going to succeed. That's just the reality of early-stage startups. So it's a very bumpy road for them. 

When we talk about this kind of learning, we're not just talking about the scientific and technological learning that has to happen. But what has to happen when you build a new industry from nothing. You have to learn how to operate within regulatory environments, and how to operate when there aren't clear regulatory environments. 

You have to think about things like: Do I have the right staff? Do we have enough expertise in the right disciplines to build a new industry? So I agree with this concept of doing things based on potential learning. But I think we should take a more holistic view of what that learning looks like, acknowledging that we are trying to build an industry where there is not an existing industry. 

FREYA: I might hop in and say, I totally agree. I think real deployments are some of the most interesting avenues for learning. But we have to make sure that learning doesn't stay behind closed doors. We have to figure out how to move that learning outside of a transaction, outside of a startup, to make sure it's available to the public. Especially because most of these startups won't stick around probably. 

KRISTAN: Let's talk a little bit about the economics and funding for these things. What are we seeing as some of those economic drivers? We talked about the startup world. Could you give us a little bit of the landscape as to what you're seeing through all these various technologies? Then I think we can broaden into the market conversation. 

FREYA: As has been alluded to, right now, a lot of the Cedar deployment is happening in the context of the voluntary carbon market. Essentially, this market is one in which mainly corporate entities are buying credits that represent a ton of carbon removal. Then they are using those credits to make claims to the public. Things like, ‘My milk is carbon neutral.’ You've probably seen these marketing claims. They're making that claim because the story is that, by buying that carbon credit, they are enabling a new climate good to happen. 

So this is the context in which much carbon removal deployment is happening today. It's been a powerful tool. We’ve had very forward-thinking buyers who are willing to pay quite a lot to support novel deployments that they think will help bring about carbon dioxide removal learning. 

Just to give you a sense of costs, the Department of Energy has a program they're calling the Carbon Negative Shot and their big dream goal is gigaton scale carbon removal. So that's billion tons per year at a cost of 100 dollars per ton. That is a lot of money. And today, we are transacting around tons that are much more expensive than that. So direct air capture -- which uses chemicals to pull carbon out of the atmosphere and then puts that carbon underground or into some other form of permanent storage -- that's often on the order of 500 to more than a thousand dollars a ton.  

Things like enhanced weathering, you're seeing maybe 200 to 500 dollars a ton. Some things like biochar, which are less durable but more practiced, may be a little cheaper than that. But we are not yet at the 100 dollars a ton mark. 

Those prices reflect first-of-a-kind deployments. That's hard, and there's a lot of learning to do. But even if we hit that 100-dollar-a-ton benchmark, we're talking about hundreds of billions of dollars a year to support this tool that we think we’ll need.  

WIL: I think, in the longer term, we're going to need public mandates. We're all going to have to pay to clean this up. These markets are incredibly small. We don't have a social cost of carbon that really reflects the actual cost of carbon emissions. Consequently, we don't have the market signals that drive corporations and others to embrace carbon removal. Especially if it's costing hundreds of dollars per ton, for example. Our Institute believes that in the longer term, if we're going to get to 10, 15 billion tons, we're going to need legal obligations. It may be the case that, ultimately, we’ll rely on a utility model. 

We ultimately adopted that model for waste disposal, right? We all pay for it. And it hopefully reduces the amount of waste that we produce as a consequence of those market signals. Similarly, we could have public carbon removal as a utility model in which we all pay for cleaning up the garbage that we've put into the atmosphere and benefited from. Or we could have obligations for corporations: For every ton of carbon emissions, they pay for a ton of removal. 

But in my opinion, if we continue to rely on the kindness of strangers and voluntary carbon markets, the yield is always going to be so modest that carbon removal is not going to have a substantive climate impact. 

FREYA: Yes. I could not agree more. 

KRISTAN: Anything else on the incentive mandate conversation or market conversation? 

CELINA: I work in public opinion. Most people haven't heard of carbon dioxide removal, which is probably unsurprising. And when they do learn about it, there's general interest. That interest starts to go south when they're told they’ll have to pay for it. 

As we're experimenting with physical and natural science, we also need to be experimenting with social science. What’s much more popular than having the average taxpayer pay for carbon removal is to have companies that have historically emitted carbon dioxide be responsible for a share of that historic emission. 

People seem to agree that it’s fair for an entity to be responsible for its current emissions. Where it gets a little murkier is: When did companies know that their product was going to create this climate change problem that the public would have to assume liability for? When do we start the clock? How do we negotiate that? 

I think, ultimately, this challenge will have to be brought into the public realm. When we're asking questions about equity, the average person is looking at this waste management problem and saying, “I contributed some to it, but I didn't make billions of dollars off it.” 

How are we thinking about companies not just being strangers that voluntarily step up to buy into this carbon market? How do we think about what is just, in terms of cost allocation in this very expensive undertaking?  

ALICIA: Let me just add on to that last about incentives. There are different incentives that different sectors have for removing carbon. So if you're corporate, your incentive might be one of optics and brand reputation. You want to remove carbon and be carbon negative. If you're, for example, a municipality or government, you might care about quantifiable progress toward climate goals, or maybe even being a good global steward. 

There are all sorts of incentives for doing this. One thing that all of these have in common is that we have to think about how to quantify the amount of carbon removed. I think we're going to get on a topic about monitoring, reporting and verification. Not an abstract question of whether a pathway can remove carbon -- but how much does it actually remove? 

It's useful to keep in mind that for every single one of these pathways. There remains an open research space about how to quantify carbon removal. That matters a lot, both in terms of whether we can have carbon markets that are credible and whether we even understand our global carbon budget. It sometimes comes as a surprise to people that we have a lot of uncertainty about what our global carbon budget is. So as we're learning how to address this accounting problem with individual projects, we're also learning about how to do better global accounting of greenhouse gases overall. 

CELINA: A carbon budget, really briefly, is the amount of carbon that we can still emit before reaching critical thresholds.  

KRISTAN: Thank you. Let's talk about verification, which is the tricky thing we've been alluding to. Give me a sense of that spectrum: What are the things we’re really good at quantifying and not?  Freya, do you want to start with that? And I would love others to chime in too.  

FREYA: Sure. So something like direct air capture showcases both ends of that spectrum. With direct air capture, we can meter how much carbon dioxide is coming out of a pipe from that facility. We can quantify that really well. We can meter how much carbon dioxide goes underground into geologic storage. Questions we might have more uncertainty around are: What does it mean for direct air capture to require a lot of renewable energy? How should we account for that? How should we account for the impacts on the grid? 

It’s possible that, because a direct air capture facility is using that renewable energy, someone else can’t. That type of systemic secondary effect question is hard to answer. We're still figuring out how to do that, not only in direct air capture, but also in other climate technologies like hydrogen. 

Another on the challenging end of the spectrum...We have mentioned a couple of pathways -like enhanced weathering or ocean-based pathways - which are often referred to as open system pathways. That's because we do the first action. We spread rocks or we add alkalinity. But then we are relying on complex systems like the ocean and soils. We are relying on watersheds to remove carbon over large spaces and time. And that's just hard to observe. We can't observe it directly. We can use tools, models and system observations to bound our uncertainty. But those are hard quantification questions. 

I think it's interesting to tie this verification challenge back to the question of: What kind of incentives are we setting up? If we’re operating in a carbon market where somebody gets to buy a ton of carbon and claim that they have absolved themselves of a fossil emission, you want to be sure that that ton represents something real and quantified. If, instead, you are operating in a space where you think carbon removal might have some important co-benefits – for example, if enhanced weathering is providing pH management benefits in an agricultural system - and you know that it's directionally right – you'd probably be more comfortable with uncertainty about the exact quantification. It’s important to marry our ability to verify things with confidence in our incentive system when deploying technologies. 

KRISTAN: Okay, I want to bring in an audience question, which is: “Since we have limited resources, why not focus more on proven processes like energy efficiency for new and existing buildings, renewable sources of energy, storage, et cetera? In a resource-constrained world, why don't we do that?” 

WIL BURNS: I think the simple answer is: We waited so long to get our crap together that we now need to do both. That's unfortunate, right? If, back in the 70s, we had begun those things in earnest, we probably wouldn't be talking about any of these things now. Solar radiation management, those aggressive interventions. But we didn't. Even though we put the Paris Agreement in place, emissions still continue to grow every year by 1.2, 1.5 percent. Every year that happens, we need more carbon removal. 

We need to simultaneously decarbonize the world economy and utilize carbon removal. One hopeful note is that the more quickly we decarbonize the economy, the less carbon removal we'll need in the long term. That always needs to be job one. We need to ensure that carbon removal is never touted as a way to avoid decarbonization. Because it can't be. We could not conceivably scale it to a level that would mean that we don't need to decarbonize. It doesn't make the most sense from an economic perspective. 

What the experts now tell us is that all of the things mentioned in the question and carbon removal will be critical if we're going to meet the short, medium, and long-term goals that I talked about before. 

CELINA: Just really briefly, I think CDR is the new kid on the block. And it's raised a lot of hype. If we look at recent infrastructure packages like the Inflation Reduction Act, the bipartisan infrastructure law, they had large carve-outs for CDR. But the bulk of the climate funding still went to energy efficiency, renewable energy, and things like that. 

I think we see a lot about CDR because it is this new and exciting area. It makes us think that priorities are shifting, and that isn't necessarily true. It’s something that we have to keep an eye out for, because we don't want CDR to take the place of these other things. But it hasn't yet, and I'm hopeful that continues.  

ALICIA: Just one more point on this. Carbon dioxide removal doesn't work unless you have lower-carbon energy sources to power it. Freya pointed out that we'd have to account for all greenhouse gas emissions through the entire process of carbon removal. That process can be energy intensive. It can be transportation intensive. So it's hard to get true net carbon dioxide removal unless you also create more low-carbon energy sources and transportation sources simultaneously. They have to go together. 

KRISTAN: This goes back to public opinion polling. What efforts are being made to get the public primed to have this basic knowledge of CDR? For when policies, regulations, mandates, markets are ready? 

CELINA: So when we talk about publics, there's the national public - folks who are voting, going to the polls – and there are local publics – folks living or working near the projects that are being deployed. 

The first category of folks - the general public, the news media, certain climate outlets - has gotten much better about reporting on these things. They’ve gotten better about clarifying the differences between carbon dioxide removal and, say, point source carbon capture and storage. Those two terms often get confused. Carbon capture and storage is a filter that you add to an emission source. 

We're going have to work with sources to prevent those emissions from going into the atmosphere. So I think educators are being educated. That is, folks who are writing about this space. And then in terms of local publics, one of the things that has been effective is the single largest government investment in CDR to date -- not only in the U.S, but globally -- is the Direct Air Capture Hubs program. That is for large fans blowing air through a filter that catches that carbon dioxide, which you can then pump underground or turn into long-lived materials. That program, really shrewdly, was placed under the Biden administration's Justice 40 initiative. 

That initiative says that, as we are transitioning to this clean economy, 40 percent of the benefits should flow to the communities that have traditionally not seen those kinds of benefits. Either energy communities that have helped to power our economy and are now in limbo - or environmental justice communities that have borne the burden of pollution in their backyards without seeing benefits. Under that program, any company that wants to get money from this 3.5-billion-dollar pot of funding needs to submit a community benefits plan. And that forces them to think about how they are engaging local communities – so that the work is mutually beneficial. There are issues with how the program is working. But it’s a huge start to tie funding to education and community engagement.  

KRISTAN: Anything else?  

ALICIA: Yeah, I want to just add two points. What research has shown is that one of the most trusted sources of CDR information is the scientific community. They tend to be considered independent brokers of information about carbon dioxide removal. They exist at universities and national centers, et cetera. Part of this journey, in terms of engagement, has been happening within the academic sciences.  

There has been a trend in the last 10, 20 years of more and more mainstream academic scientists starting to engage in fundamental research into carbon dioxide removal and developing scientific disciplines around it. That's an important piece in helping build out social acceptance of CDR. In terms of: Is it something we want to move forward on?  

The second point I want to make is that dealing with these questions is thorny and takes time. My experience has been that people have to sit with this information about carbon dioxide removal, about what that means for us as a society, for a long time before arriving at a clear viewpoint. 

So I encourage you all, as you're on this journey, to give yourself a lot of space to spend time thinking about this potential space. Because it's a really wild place we've found ourselves in.  

KRISTAN: That's awesome. I'm going to move us into closing thoughts. What's a misconception that you have come across that you feel like you have to address all the time, or one that is new for you? I would love each of you to give me an example and explain why it's a misconception. 

FREYA CHAY: So, I think this one showed up today in how we all talked about carbon removal. We’re imagining that we’ll use gigatons of carbon removal to stabilize global temperatures. That is a tremendous amount. It’s hard to even conceptualize how much mass that is. 

We often frame the carbon removal conversation around getting to that number. But I think the better question is: how quickly can we figure out if we have this tool and at what scale? So that we can change the rest of our planning. 

CELINA: Yeah, I think there's often conflation between preventing carbon dioxide emissions and removing them. That gets thorny when it comes to land-based pathways. For example, when we're thinking about protecting a forest, does that count as negative carbon if that capture was already happening?  

On the technological side, I work a lot on direct air capture. So, taking emissions that are out there mixed in the atmosphere, versus carbon capture and storage, which is trying to take carbon dioxide from a flume. Like from a power plant smokestack or from a chemical process. 

It sounds wonky that we need to differentiate removal from prevention of emissions. But it’s important for accounting and policymaking - making sure that folks who are making climate-related claims are actually following through with them. That is a really important distinction and that cross-cuts all of these pathways.  

KRISTAN: You got one, Wil?  

WIL: Yeah, I don't know if it's a misconception as much as a sentiment that I worry about. And that is: Is if any of these approaches have risks, there is a segment of the community that says we shouldn't do it. I fear it includes non-governmental organizations. 

We really, at this point, need risk trade-off characterizations, right? Because there's a massive risk of unchecked climate change. What that means is, because we didn't get our crap together when I was young, there's no free lunch. 

Everything is going to have some risk. What we have to do as a society is try to characterize that risk as accurately as we can. To try to minimize that risk as much as we can. And talk, as a society, about what kind of risk we're willing to incur and how we protect the most vulnerable. 

But taking the position that, if any of these things could cause harm, we should discount them, is not a rational way of looking at climate policymaking, in my opinion.  

ALICIA: Thanks for that. What I find most frequently is conflation. In terms of how we think aspirationally about CDR - our readiness to do it - versus where we are right now. 

So it's important to remember that we're just learning to walk right in this journey with CDR. That's true on the science side, the technology side, the engineering side, on all sides. So I remind people that there's an urgency that's not just around deployment at scale. We may not get to that point. 

But there's an urgency around the learning and the trying - putting forth our abilities as scientists or folks in the technology and policy spaces. Moving quickly so we can learn as much as possible. 

KRISTAN: Thank you. I'm going to give you all one final thing. I want you to think of one question that you wish you had the answer to right now.  

ALICIA: I'll start. The big question that I have very often is practical. Is there a future where we have carbon markets? And are they voluntary or compliance markets? Or do we have a future where we have governments stepping to mandate carbon removal without a market-based mechanism? It’s an important question for me, personally, in terms of our business model at [C]Worthy. Who are we building quantification tools for? Are we building them for market participants or are we building them for government and policy participants? 

FREYA: That was essentially my question, also. Carbon markets have been super useful. They also come with significant constraints. If we could move past the assumption that this all happens in the context of a carbon market, what could we imagine in terms of public support for getting this stuff off the ground? 

CELINA: Yeah, earlier in one of my answers, I said that the bulk of the funding is still moving toward traditional climate solutions and that's how we should continue. I came into this field thinking about the moral hazard of carbon dioxide removal. Which is to say, if you present policymakers, industry, and the public with the option of removing emissions after the fact, their willingness to prevent those emissions in the first place will be lowered. 

And there is complex and contradictory social science about how this happens and whether it happens at all. So while we're seeing the bulk of the funding going toward energy efficiency, renewable energy and all of these other things, we don't have a crystal ball. We’re not able to see what the counterfactual would be for policymakers, industry, the public, and how ambitious they would be about climate change if they didn't know about carbon dioxide removal. 

So one of the things that we've done up here is continue to repeat that carbon dioxide removal is not a silver bullet. It doesn't work without mitigation. That's a science communication tool that is being used intentionally to try and address some of those moral hazard concerns. 

One question I have is how can we continue to elevate that urgency around acting on climate? And make CDR a tool for increasing rather than leveling out or decreasing that urgency? I think that is a very real, open question. One that hopefully we can all think about together.  

WIL: Yeah, it's just fascinating that we all end up in the same place. Because for me, the question is how do we effectively communicate this to the public, given that the public has a lot of things to think about? We have politicians who actively propagate the theme that ignorance of science is a badge of honor. How do we get past that and get the public to think about this? Because ultimately, if we're going to do carbon removal at scale, it could cost us trillions of dollars, right? And it may be money well spent. But in any democratic system, the public has to decide if we should expend those funds. Or, at least, they should have a substantial role in deciding how we expend those funds. 

Unless we can effectively communicate why we think it's necessary, what the trade-offs are, what values are most important, and get the public to provide their take on this, we've really failed. It can't just be technocracy driven and science driven. But it's very difficult to cut through the miasma of all the things that that we, as a public, have to think about. 

KRISTAN: Thank you. Everyone please join me in thanking this panel. Thank you all for being here today.  

For more on this series visit our Climate Interventions page.  

Disclosure statement:
The Institute for Science & Policy is committed to publishing diverse perspectives in order to advance civil discourse and productive dialogue. Views expressed by contributors do not necessarily reflect those of the Institute, the Denver Museum of Nature & Science, or its affiliates.