Carbon removal

Fuzzy math and food competition: The pitfalls of sourcing biomass for carbon removal

A forest scientist explains how to reduce harms when using bio-based resources for carbon removal.

January 23, 2024
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Plants capture hundreds of gigatons of carbon every year in timber, crops, and other forms of biomass. Much of that carbon gets released back into the atmosphere through natural processes and human intervention. But there are a few ways that we can lock it away for good, like biochar, bio-oil, and bioenergy with carbon capture and storage, or BECCS — all processes that fall under the umbrella of biomass carbon removal.

The International Panel on Climate Change calls carbon removal “unavoidable” — and biomass is a leading carbon removal contender. But everyone wants a slice of the biomass pie. Airlines want it for jet fuel. Midwestern legislators want it for ethanol. Homebuilders want it for construction. Oh, and humans want it for food. By 2050 potential demand for biomass could far outstrip supply. 

So what kinds of biomass should we use for carbon removal — and where should we get that biomass from?

In this episode, Shayle talks with Dr. Bodie Cabiyo, senior forest scientist at climate science consultancy Carbon Direct and lead author of A Buyer’s Guide to Sustainable Biomass Sourcing for Carbon Dioxide Removal.

They talk about topics like:

  • How carbon removal is already competing with other uses for biomass.
  • The complicated question of what counts as “waste,” which some BECCS companies are using to claim carbon reductions.
  • Principles for sustainably sourcing biomass for carbon removal, like tracing chain of custody and avoiding market distortions.
  • The environmental and carbon math tradeoffs involved in different sources of biomass.
  • What Shayle would do with biomass if he were an omnipotent global leader.

Recommended resources

  • Carbon Direct: A Buyer’s Guide to Sustainable Biomass Sourcing for Carbon Dioxide Removal
  • Catalyst: From biowaste to ​‘biogold’
  • Energy Transitions Commission: Bioresources within a Net-Zero Emissions Economy: Making a Sustainable Approach Possible

Sign up for Latitude Media’s Frontier Forum on January 31, featuring Crux CEO Alfred Johnson, who will break down the budding market for clean energy tax credits. We’ll dissect current transactions and pricing, compare buyer and seller expectations, and look at where the market is headed in 2024.

Catalyst is supported by Antenna Group. For 25 years, Antenna has partnered with leading clean-economy innovators to build their brands and accelerate business growth. If you’re a startup, investor, enterprise or innovation ecosystem that’s creating positive change, Antenna is ready to power your impact. Visit antennagroup.com to learn more.

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Shayle Kann: I'm Shayle Kann, and this is Catalyst.

Bodie Cabiyo: This waste wood sort of framing is wrong and I think misleading, and I think ultimately we're going to have to evolve past that if we're going to make useful for frameworks for this.

Shayle Kann: When it comes to sourcing biomass for carbon removal, there's good and there's bad, and it's very important to know the difference. I'm Shayle Kann, I invest in revolutionary climate technologies at Energy Impact Partners. Welcome. So biomass is potentially a pretty incredible resource for carbon removal. You're, I'm sure, familiar with direct air capture where we build big engineered machines to suck CO₂ out of the atmosphere. But why not let photosynthesis do the work for us? Plants, of course, already uptake a truly incredible amount of CO₂ globally. And so instead of letting them die and decompose and re-release the CO₂ into the atmosphere, why don't we just lock that CO₂ away and keep it out of the atmosphere?

Shayle Kann: It's undoubtedly cheaper and it could be super scalable just given the amount of photosynthesis that takes place already in the world. But of course, the biomass itself is the rub. It's inherently limited in supply, though bigger than you might think. And of course there are other uses for it. You can also turn it into aviation fuel, you can make it into bioplastics, you can turn it into animal feed, et cetera, et cetera. And also the news is littered with stories of poor biomass sourcing practices leading to all sorts of problems ranging from bunk carbon claims to negative environmental effects, to impacts on local populations.

Shayle Kann: I am, to be honest, worried about this. I'm excited about all the innovation that I see in biomass CDR and in sustainable aviation fuel and all these other things, but I do worry about what happens when this really starts to scale. So if you are thinking about using biomass for something novel, the question is how to do it right? And that's the topic of a paper that was recently published by our guest today, Dr. Bodie Cabiyo, who is a senior forest scientist at Carbon Direct. Bodie's paper is a literal guide for sustainable biomass sourcing. So let's talk through it. Here's Bodie. Bodie, welcome.

Bodie Cabiyo: Thanks a lot. Happy to be here, Shayle.

Shayle Kann: Talk about the right way and the wrong way to source biomass specifically for biomass-based carbon removal. Maybe starting with the quick definition there. I think a lot of folks who listen will be at least somewhat familiar with the concept of using biomass for carbon removal, but give a quick refresher on what that entails, what that umbrella term includes. And then I also want to talk about what is similar and dissimilar about sourcing biomass for that purpose versus other purposes.

Bodie Cabiyo: Yeah, for sure. I'll jump into the first one just to start. So this all starts with plants, right? Plants are incredibly good at sucking CO₂ out of the atmosphere. If you look at a global scale actually, plants photosynthesize about 400 gigatons of CO₂ every year, and that actually shows up in our CO₂ readings. If you look at the CO₂ curve for the world, the Keeling Curve that's measured at Mauna Loa Observatory, you have these spiked that are seasonal spikes because the Northern Hemisphere is sucking so much CO₂ out of the atmosphere. The challenge is that most of that CO₂ is then lost back to the atmosphere through respiration, through animals eating plants, us eating plants, some of it's harvested. So we've managed a lot of forest for paper and wood products and things like that. And a lot of that actually ends up back in the atmosphere as well.

Bodie Cabiyo: So the basic idea with biomass-based CDR is just to capture some of that carbon that's being re-released back to the atmosphere from plants. And there's a wide range of different engineering solutions to this. So the simplest is you just take some plant matter, you take some biomass, you put it into a clay pit and you bury it and it stays there for centuries. That's wood vaulting or biomass burial. The complexity goes up from there to making biochar, which is pyrolytic combustion of biomass that then stabilizes some of the biomass in a recalcitrant form, that's basically charcoal. It’s even more complicated where say you're doing a Fischer-Tropsch process and you're producing a liquid fuel and then you're capturing the CO₂ from that process and storing it in a geologic reservoir. So there's a lot of different pathways. And like you alluded to, the real trick is figuring out where the heck the biomass is coming from and what the implications of the biomass sourcing are.

Shayle Kann: Right. And yeah, that last category, the Fischer-Tropsch process plus carbon capture, that's BECCS, bioenergy plus CCS, and there's even some other subcategories. But as you said, the point here is the common thread for all of those forms of biomass-based CDR is that they need biomass. And so when you're in that world, you enter the thorny realm of sustainable biomass sourcing. I guess before we get into it though for CDR, it's not just CDR that needs biomass. We also can and maybe will use biomass for a variety of other purposes, including a number of others in climate tech. Maybe it's sustainable aviation fuel without the carbon capture, maybe it's bioplastics, whatever. As we talk about sustainable biomass sourcing, do you think that the principles here apply no matter what you're sourcing the biomass for? Or are there some that are unique to using the biomass for carbon removal?

Bodie Cabiyo: Yeah, I think this question gets it. It's a really good question, and if I'm being honest, it's one that I think we actually haven't really grappled with well enough as a community. We haven't grappled with it well enough in a regulatory context. There are a ton of different uses of biomass, ones that we're all familiar with on a daily basis. Like my desk right now is made out of wood. I think sometimes people forget that fact when they talk about harvesting trees, it's a bad thing, but they're writing that critique from a wooden desk. But if you look at all of the different plans for using biomass, if you look at the potential bioeconomy is what we call it in say 2050, there's a huge mismatch between the supply and demand there of biomass and biomass uses. And that mismatch is based on the best estimates that I've seen. That mismatch is something on the order of 11 to 16X.

Shayle Kann: In other words, 11 to 16 X more uses in a bioeconomy for biomass than there is biomass.

Bodie Cabiyo: Exactly, yeah. If you look at all of the possible sustainable forest management we can do, and all of the dedicated biomass that we can grow in 2050, there is 11 to 16 times less of that supply than there is potential demand that we would have through things like bioenergy with carbon capture and storage or sustainable aviation fuel or paper or two by fours and lumber. So there's this huge mismatch between the two, and that's honestly the thing that keeps me up at night. When we get to 2050, how are we going to decide what we actually use that limited resource for and what is the best and highest use for that? So there's this concept called cascading use, which is basically that given we have a limited biomass resource, we should dedicate that limited resource to the best and highest use. And then maybe you have recycling and it sort of works its way down the chain and eventually you combust it in a biomass combined heat and power plant and you capture the carbon.

Bodie Cabiyo: So in terms of these principles and how they apply to those different uses, I think that in general, the application is about the same across the board. I will caveat that and say I haven't done a deep dive. We did a deep dive into CDR specifically. So there might be things that emerge once we do a deep dive in the other uses, but the thing that really emerges when you're comparing those uses is what should we actually be using that biomass for? So for example, there's emerging regulatory frameworks that are coming up saying that we shouldn't be using it for biopower. If you have biopower with CCS, that's fine, but in the Netherlands, they're phasing out biopower in favor of biopower with CCS. So it all comes back to this cascading use idea.

Shayle Kann: Okay, so for our purposes today, we're going to talk predominantly about what's the right and wrong way to source biomass for CDR, but understanding there's probably a fair amount of overlap, huge amount with sourcing biomass for whatever other purpose. Let's talk about why this is a big concern. I mean, historically there have been, and it doesn't take a lot of reading of the news even today to see a bunch of examples of how this can be done poorly. How you can use biomass to do something, but it turns out that the way that you source that biomass or where it was grown or what it replaced, that kind of thing caused negative impacts that were perhaps bigger than the positive impacts, the things you did with it. And so on balance, maybe you shouldn't have done it in the first place. Can you run through a couple examples of that? What have we seen publicly that has been how to do this wrong?

Bodie Cabiyo: Yeah, for sure. Lots of bad examples, and I think that's why there's been kind an emergence of regulatory frameworks around this issue. Maybe just to back up a quick step, the thing I want to highlight that most of these biomass programs, they often claim that they're sourcing waste wood. And so that's like the shield they use. It's like, "Oh, this is all residues." It's like the leftovers from a sawmill where they're producing sawdust, so we're just going to take the sawdust and turn it to pellets and then bury the carbon. That sounds great. Waste wood is actually, I think a fairly problematic concept, and in each of the negative cases that we've seen, they always use the waste wood branding when in fact it's definitely not waste wood. And especially if we think about that 2050 scenario, waste wood is not really a thing. There's always going to be a use for waste wood.

Shayle Kann: Oh, that's interesting. So you're describing two problems. One is that they're saying something is waste wood when it's actually not, and the second is that you're saying ultimately nothing is waste in a world where we have way more demand for any biomass than we have supply of it. Is that right?

Bodie Cabiyo: Yeah, exactly. I mean, I think the kind of quintessential example of waste is like a burn pile in the forest, and arguably, yes, that is waste material right now. But if you live in a world of 11 to 16 X supply demand imbalance, then you're going to have a lot of different uses. And honestly, we're actually starting to see that today where you have biomass based CDR projects that are competing with... let's see, I was talking to somebody recently that they were saying they were trying to source logs– that was this kind of example where there's just a pile of logs in the forest. And it's assumed that it's just going to decay there or they're going to burn it in a burn pile. And they actually were running into a problem where they realized that somebody else wanted to source it for pallets. And I thought that that was a perfect encapsulation where we assume that it's waste wood, it's going to be burned to the atmosphere, and that makes the carbon accounting super easy, but that assumption is flawed even today and will become even more flawed into the future.

Bodie Cabiyo: So yeah, this waste wood sort of framing is wrong and misleading, and I think ultimately we're going to have to evolve past that if we're going to make useful frameworks for this. But getting back to your question about examples, there are definitely some good ones. I think the most recent that comes to mind is the biggest pellet producer. I think it's the biggest pellet producer in the world is Enviva, mostly they're based out of the southeast US, and they're actually going bankrupt right now, or at least it seems like they're going to go bankrupt, and that's partially because they claim that they're using waste wood, but the reality of pelletization is that you need really high quality material actually to produce the pellets. So they were saying, "Oh, we're sourcing waste wood, we're sourcing sawmill residues and treetops and branches and things like that."

Bodie Cabiyo: But if you talk to an engineer, you can't make good pellets out of treetops and branches and sawmill residues. You need whole logs to do to that well. And so what happened is they were sourcing whole logs and they have massive operations, and so in the sourcing of whole logs, they end up sourcing stuff that they probably shouldn't be. I have a colleague that has toured their facilities in the past and saw that they were pulling whole saw logs, which is like stuff you would turn into lumber like two by fours, pulling saw logs and turning it into pellets to be burned in the UK or elsewhere. So that's problematic.

Shayle Kann: Yeah, that's one of the things that when you start to read into it, you realize that the fact that this is happening is kind of wild in the first place. There's a company based in the southeastern United States that is taking wood, call it wood waste if you want. Don't call it wood waste if you don't want, but either way, turning it into pellets, then shipping it across the ocean to the UK for them to burn to produce power. That's what they're doing. And it was a fairly big business. It's kind of a wild thing in the first place.

I do want to draw a slightly clearer line around why it's bad if they just buy logs that are not waste. So the presumption there is you're taking a tree that either otherwise would not have gotten cut down or might've otherwise gotten cut down for some other useful purpose, and you're cutting it down, you're diverting it into the energy system, into the pellets that ultimately get burned for power. So because you didn't affect the demand for all the other things that we need wood for, the presumption is that on net one more tree got cut down in order to do this. And so why is that an environmental benefit? It's not carbon removal if you've caused by cutting your tree down another tree to get cut down. Is that basically right?

Bodie Cabiyo: Yeah, yeah. So I think about the potential harms in two distinct categories. So there's the carbon math, which I think you were alluding to there. Just, are we actually doing the right calculations to figure out that this is going to be carbon negative? Or in the case of biopower facilities, carbon-neutral, which is, all these facilities are predicated on carbon neutrality that if you harvest biomass and burn it, you have no net climate impact, which is probably a simplification that we should stop making. Oftentimes we can get close to that, but that's not always going to be the case. The other bucket of bad things is the bucket of social and environmental harms. So on the environmental side, this includes things like harvesting, high conservation value forest, places that have really high biodiversity. Or maybe they're old growth forest or primary forest that should not be cut down and for whatever reason that demand for biomass is enabling that forest to be cut down. On the social side, you could be harvesting areas that maybe have sort of insecure land tenure.

Bodie Cabiyo: Maybe there are land tenure issues with Indigenous peoples, for example, and disputes over land rights. You could also have harms within the biomass supply chain. So for example, with pelletizing, there's a lot of noise and a lot of pollution that comes with that pelletizing process. Actually, as a fun aside, I used to work in the world of clean cook stoves. And during that process I worked in Rwanda for a little while and there was a pellet mill there that was trying to make pellets to burn in clean cook stoves in Rwanda. And I got to tour that pellet mill and can confirm that it was incredibly noisy and incredibly dusty, and I don't think the local community was super happy about having in their backyard. So that's just an example of some of the social harms there.

Shayle Kann: Yeah. We've been talking mostly about the wood waste stuff. I'm curious how you think about ag waste. That's the other category where people often refer to using biomass, using waste biomass, right? There's forestry waste, then there's ag waste, and so this is corn husks or whatever, and the presumption there is we grow crops, we use those crops for agriculture purposes. But there's a bunch of biomass that does not get used, and that stuff would otherwise similarly go sit there and decompose or in one way or another, release the CO2 back in the atmosphere. And thus, if we divert it and bury it or do whatever we're going to do to it then it is indeed positive. Do you think about that similarly to the wood waste story or is ag waste different?

Bodie Cabiyo: Ag waste is in some ways simpler and in other ways more complex. I will caveat this by saying that I'm a forest person, so there are people that spend their entire careers thinking about ag waste, and for this report that we published, we focused explicitly on forest waste partially just to create a tractable boundary around the problem. If you set a global scale for your assessment, it's hard to actually gain traction in terms of finishing the thing. So we did focus on forest waste or forest biomass rather. But with ag waste, I think it's simpler in some ways. If you have true agricultural residues, like in California for example, we have a lot of orchards in the Central Valley where they grow their crop like almonds for several years, decades, I actually don't know.

Bodie Cabiyo: And then they have to tear it up and oftentimes that actually gets burned. So there are a lot of startups that are working on converting the agricultural waste, and I think that in that case, it actually is waste into durable carbon removal. There are some trade-offs sometimes. So for example, if you look at, some facilities are looking at using straw in BECCS facilities, biodegradable carbon capture and storage. And for the most part, the social environmental harms piece of things is pretty straightforward. It's mostly a waste product. From the carbon accounting perspective though, with that, you have to be really careful of soil carbon. So if you are leaving straw residue on a field and letting it decompose it actually, a lot of that carbon ends up stored in the soil up to a certain threshold.

Bodie Cabiyo: So if you start taking it off, you can actually get decreasing soil carbon, and that's usually not reflected in the carbon accounting of those kind of facilities. So there are some sort of particular sticky issues around ag residues, but its overall can be simpler. The other category, which I think is one that we're going to have to start thinking about a lot more is dedicated feedstocks. So we're seeing this in the US where we have corn ethanol, and we're growing millions of acres of corn for producing ethanol, and that has a lot of really tricky implications about food supply and market leakage and things like that.

Shayle Kann: Yeah. I mean, I think a lot of people know the ethanol story, but not everybody, can you just spend 30 seconds on that one? We ended up with ethanol, corn ethanol in the US, thanks to policy largely. But now the result is that an enormous amount of the corn that we grow and the United States goes toward the production of ethanol when presumably otherwise either that land would be used for something else or it would be corn that would be used for food. So that's basically the concern that has emerged, and it's a big part of what we're trying to avoid if we're going to scale up biomass use for CDR, right?

Bodie Cabiyo: Well, and the other thing to be aware of– there is that there's actually a lot of energy that goes into the production of that corn. So you're producing corn, you're not actually harvesting the cellulosic part of the corn, you're leaving that, presumably they leave it to decay and plow it into the fields. So you're just harvesting the corn and there's a lot of fertilizer. There's a lot of mechanical input. So if you look at the carbon balance of that, it's okay, but it's certainly not great. It gets better if you add CCS to those operations where you're capturing the mostly pure stream of CO2 that's coming off of a corn ethanol facility. But just based on the carbon balance alone, it's not really a great deal, but it turns out that it's easier to make ethanol out of corn than it is out of cellulosic feedstocks like wood and corn stover. And so I think a lot of the most exciting startups right now are focusing on cellulosic feedstocks, and that's really the future of biomass solutions, I think.

Shayle Kann: All right. So we talked about some of the ways to do it wrong. You can call something waste when it's not waste. You can assume that the fact that it's waste now means it's going to be waste forever. You can use dedicated crop that would otherwise have some other useful purpose and that you can have sort of leakage effects, you can have whatever, there's a bunch of ways to do it wrong. Let's talk about how to do it, which is sort of the purpose of the paper that you put out recently, at least to set some principles for what would it take to do it. So I just want to run through those high level principles and talk through them a bit, starting with the first one, which is sort of oversight and transparency, which is probably obvious to some degree. But in this particular context, what does it mean for there to be oversight and what sort of transparency is important to maintain?

Bodie Cabiyo: Yeah, so oversight is really critical here. I think it's critical with all kinds of agricultural commodities, but you need to know where the biomass is coming from, especially when you're talking about something like pellets that can be shipped for long distances. You want to know if it's coming from an old growth forest in British Columbia, which is bad for the record, or if it's coming from a sustainable forest in the US Southeast. I think that is the foundation of all of this. If you don't know where your biomass is coming from, then you can't ascertain whether or not it's going to be sustainable. And unfortunately right now, this is actually pretty hard.

Bodie Cabiyo: We have these kind of crude oversight frameworks, or sorry, supply chain transparency efforts that they look at sort of the sourcing area. So you know roughly, "Okay, we got the biomass from this pellet mill and this is the woodshed for this pellet mill." But they don't actually trace it down to the forest so you actually know that that biomass is coming from a sustainable forest, and this is where it's important to have two things. So it's really important to have full chain of custody, which is going to be increasingly common partially because of EU regulations that are coming online in a couple of years. The EU deforestation regulation is going to be probably kind of a game changer.

Bodie Cabiyo: We'll see how much the global effect is, but that'll force at least products that are coming into the EU to have full chain of custody tracking all the way back to the source, all the way back to the forest that they come from. The other thing is having forest management certification. So basically that means that somebody from the Forest Stewardship council that's been around since '93 and is a pretty excellent nonprofit organization. They actually go into the forest where the wood is coming from and they make sure that it is achieving a certain set of outcomes that are sustainable. So those two things, having the supply chain transparency and chain of custody and then having the actual on the ground forest management certification is kind of the gold standard.

Shayle Kann: I kind of think of this as being sort of similar to battery minerals. If you're going to buy cobalt to put in a battery, probably you need the same set of things. It's a different process of getting full chain of custody for cobalt from wood waste or whatever. But it's a common thread across a number of areas within the energy transition where you need this stuff if you're going to do a thing, you just need to make sure that you know exactly where it comes from and that the place that it comes from and the process that it was used to produce it is sustainable.

Bodie Cabiyo: Yeah, exactly. I think it's a broad sustainability issue, and I hope that as we're getting better technology and we have a more information-rich economy, we'll be able to do this more and more with all of our products.

Shayle Kann: Okay, so let's go on to the second high-level principles. So first one's oversight and transparency. Second one is minimizing negative externalities. So we talked a little bit about some of the negative externalities that have happened in the past, but how do you think about that one in particular? It strikes me that there's probably a slippery slope there. It's tough to eliminate all negative externalities. You're going to be using a lot of biomass if you're going to do this at scale. If we're talking about gigatons of CDR using biomass, there are going to be negative externalities. There's no question in my mind. So how do you think about, what is the line that you can draw there?

Bodie Cabiyo: Yeah, I mean, thinking about social externalities first, it is a tricky line to draw because sometimes it's hard to know what level of community engagement is appropriate, right? Say if you start industrially managing a forest that wasn't previously managed and the local community doesn't like that, is that how do you weigh those relative values of having an effective climate solution with the local impacts on the communities? There's an interesting case in Estonia right now where they have a lot of what we call in forestry called structurally overstocked forests. So basically what happened is during the Soviet era, there was a lot of agricultural land abandonment that turned into reforestation.

Bodie Cabiyo: And now, 60 years later, a lot of those forests are maturing. And what you have is you have forests that maybe they've been around for a whole generation to somebody like you or me, those forests have been there forever, and they might as well be old growth forests. And there's a lot of social value in Estonia placed on those forests, and now they're starting to be harvested partially because they're mature, they're at the age where they should be harvested from a cultural perspective. So it brings up this tricky question of, well, how do you weigh different social cultural values? How do you weigh the existence value of that forest and the ability to forage for fruits and nuts and mushrooms versus the desire to harvest the forest and use that wood for biomass? So yeah, hard to draw lines.

Bodie Cabiyo: There are places where there are easier lines to draw. So for example, I mentioned earlier pellet facilities and where you site those is going to be critical in terms of the impacts in communities and how you engage the local communities is really critical. So I have a bunch of great colleagues at Carbon Direct that are specialized in environmental justice and community engagement. And it's really, really critical to make sure that you're actually engaging the local community in the process of setting those kind of facilities. And that's true across the CDR world if you're talking about a pelletization facility or you're talking about a director capture facility. So there's a whole range of potential social impacts and definitely ways to navigate those, but maybe not a lot of clear lines.

Shayle Kann: Yeah. I like often to remind people there is no free lunch in decarbonization. The scale at which we're going to need to do a lot of things is inherently going to cause some side effects. And so it's always with these things, it's a matter of figuring out what is acceptable and what is not, and what is the cost of doing a thing versus what is the societal cost of not doing the thing. Again, not to bring it back to battery minerals, but it's another perfect example of the exact same thing, right?

Shayle Kann: If we're going to produce enough batteries to electrify the entire passenger vehicle fleet in the world, we are going to mine a lot more minerals. There's no way we're not, and new mines have a bunch of cascading ramifications. And so similarly here, I think it's the right principle to say you need to minimize negative externalities and there's not going to be a perfect line over which you cannot cross in every case. But clear visibility into what those negative externalities are. And then decisions can get made either through regulatory means or by the market at least with good information and visibility.

Bodie Cabiyo: Yeah, that's exactly right. And I do love the mining example. In fact, I was talking to my mom, she's a hardcore back to the land hippie who also, she really wants us to fight climate change, but every time you talk about some of these hard trade-offs, it becomes a hard conversation. And we were talking about metals for batteries and I don't know if this is still the case. I mentioned there was a mine, I think it was a cobalt mine proposed in Montana or something. And I was like, "Well, this is on the surface."

Bodie Cabiyo: I spent my childhood actually fighting a gold mine in my backyard or going to a court proceedings with my mother, and on the surface, a cobalt mine in Montana seems like a pretty bad deal from that lens, but it's a whole hell of a lot better than the alternative, which is mining cobalt and open pits in the DRC with child labor. So we have to have this kind of nuanced thinking. Sammy Roth at the LA Times, they did a great piece on this a couple of weeks ago, just calling out sort of like the green on green fighting over trying to find the perfect solution.

Shayle Kann: Right. Okay, so first principle, oversight and transparency. Second one, minimize negative externalities. Third one, avoiding land use risks. So again, we've alluded to this one a little bit, but talk a little bit more about, because this one I think is really important as we scale up. Today the world of biomass based CDR, indeed, the entire world of CDR is very, very, very small. But the whole presumption of this idea that we are going to... that a significant portion of our solution to climate change is going to be carbon removal, is dependent on scaling CDR up to gigatons. Gigatons is billions of tons, billions of tons means a lot of... And if any meaningful portion of it is biomass based I should say, then that means a lot of biomass based CDR. And so the land use question to me really comes into effect as we picture this industry scaling. So how do you think about the land use risks that can be presented here? And again, given whatever you said, 11 to 16 X under supply that we may face by mid-century, how is it possible to avoid significant land use risk?

Bodie Cabiyo: Some of the things are relatively straightforward, so I think most people with some caveats, most people can agree we shouldn't be chopping down old growth forests and feeding it into biomass boilers. That's relatively clear. I say there are some caveats there because in the context of the Canadian boreal forest, after this incredible fire season they had where talk about up into the right not being a good thing. If you look at the area burned this year in the Canadian boreal forest, it is actually not just boreal, but the Canadian forest in general is pretty incredible. So there is actually some discussion happening around wildfire risk mitigation in those areas. But in general, harvesting old growth forests and feeding it into BECCS and biomass CDR systems is not a great thing. Same thing for areas that might not be old growth but have high conservation value, also generally not a good thing.

Bodie Cabiyo: That's on the harm side of things. And just referencing my bucketing earlier, there's the carbon math and then there's the other harms. On the carbon mass side of things. This is actually one of the trickiest parts about biomass-based CDR is how you actually account for carbon changes at a landscape level. So let me lay this out in terms of a spectrum. So if you want to make a case against a BECCS facility, for example, just zoom into the level of a harvested plot. Let's say you have several acres that you clear cut, that forest now has pretty low standing forest carbon stocks on it. It's a lot of stumps and maybe some residual trees they left, but it is now a low carbon area and it'll take decades for that to grow back depending on the forest type. So if that is your sort of scale of analysis, then you actually have a really long payback period before you can claim that your biomass is carbon-neutral because like I said, it takes decades to grow back the forest.

Bodie Cabiyo: A lot of people that will critique BECCS, they'll use that lens, they'll use that sort of small scale of analysis and say, "Look, you cut down a tree, it's not going to grow back for 50 years and that's bad." That is true, but that's also the wrong scale of analysis. If you zoom out to the other extreme, if you look at the global scale, forest carbon stocks are globally stable and actually increasing because we have an increasing terrestrial carbon sink because of climate change itself, which is kind of a fun quirk of the system. You have increasing CO2, so you have the CO₂ fertilization effect, but at a global scale you have increasing forest carbon stocks. So if you look at it through that lens, you could say, "Well, heck cut down as many trees as you want because it's always going to be carbon-neutral at the global scale." That's also the wrong scale to be looking at. So the answer is somewhere in the middle.

Bodie Cabiyo: And what we came to in this report is that you should be looking at sort of a regional ecosystem defined scale where you have... maybe it's the size of a small US state where you have a kind of ecologically continuous forest and you have pockets of harvesting throughout that, but then you also have pockets of regrowth. So anytime you cut down a patch of trees for every patch of trees, you cut down rather you have another patch of trees that's regrowing actively. And so if you look at that at the landscape scale, you have either stable or increasing carbon stocks. So it's a really tricky piece and I think it's one that we still have to get right, because I had so many conversations with brilliant experts, folks like Steve Hamburg, who's this chief scientist at EDF about this particular issue, and it is really tricky and hard to choose the right scale.

Shayle Kann: Just to put a finer point on it, I think it's sort of intuitive why the smallest scale is not the right way to think about it. It's not that intuitive to me why the largest scale is the wrong way. So if it is true that the global forest stock is stable and increasing is the reason why the response to that shouldn't be, "Okay, great, we should cut down as many trees as we want, as long as we're using them for the right purpose and the global carbon stock remains stable. We can go from net positive forest growth to zero forest growth." Is the reason that that's not the right way to think about it because actually if you did say concentrate all of your tree cutting in one region, that actually then it wouldn't grow back sufficiently fast. Or why is the global scale the wrong way to think about it? If I'm just being purely practical from a carbon only mindset, forget all the negative externalities.

Bodie Cabiyo: Yeah, for sure. I mean, I think, Shayle, the omnipotent global global leader and you're optimizing-

Shayle Kann: You mean when I'm the omnipotent.

Bodie Cabiyo: Yeah, exactly. By the way, if you need advisors for that role, you know who to reach out to.

Shayle Kann: Yeah, I'll send you an application.

Bodie Cabiyo: If that were the case and you were optimizing at a global scale, you could maybe make a case for that. But I think that honestly, this is a very active debate and I don't think that there are super clean arguments to this. I actually, I don't have a super clean response to this off the top of my head. I think that the bottom line is that the local matters, and if you do have decreasing carbon stocks at a local scale, you can do a better attribution of that to say the facility that you're assessing.

Bodie Cabiyo: So let's say we have a BECCS facility in Stockholm, for example, if you look at the local forest carbon stocks that are feeding that BECCS facility, you can maybe draw a clearer attribution of, okay, this is actually causing a decrease in the carbon stock. Whereas if you scale out to the global scale, then maybe you could have adverse impacts, but you just don't pick up the signal because your scale of analysis is too large. So I think when we're doing the carbon math, yeah, we talk about gigatons all day long, but gigatons are big and gigatons are actually made up of megatons, and we have to do the carbon math at the megaton level or the kiloton level depending on your facility.

Shayle Kann: Yeah, maybe the analogy here is to, I don't know, sustainable salmon harvesting where you could say like, well, okay, I don't know, this probably isn't true, but you could say that the global population of salmon is growing. And thus if I kill all the salmon in the Pacific Northwest in the United States, it's fine because globally there's plenty of salmon. But obviously we don't want to do that. There's probably a bunch of reasons why that would be bad. Okay, final principle is avoiding market distortions. What do you mean by that?

Bodie Cabiyo: Yeah, this is a tricky one also. So market distortions could happen a lot of different ways. In theory, you could have a relatively high price on biomass and that actually disrupts the production of other goods that society cares about. So maybe we put a high value societally on having paper and having lumber. But if somehow in a given region, carbon removal fetches a really high price because say some company really cares about carbon removal, they're willing to pay premium price for it. Then you could actually have market effects where you drive up the price of other wood products and produce less of them.

Bodie Cabiyo: I think it's mostly a carbon accounting consideration. So you can imagine in that case, say, let's think about Sweden again. You can imagine a case where biomass fetches a pretty high price and you have shifting production away from saw timber for producing lumber into producing biomass. That means that you have less carbon storage because timber stores carbon, and that also means that you have lower carbon stocks in your forest because you need younger trees to produce biomass than you do. You need big trees for producing saw timber. So there are a couple of kind of carbon accounting considerations there. The way that we kind of skirted this in the report is we said, "Okay, waste is not a thing." As we talked about, there's just not really that much waste, especially in the world of forests.

Bodie Cabiyo: But we want to make sure that at least until we have better frameworks to regulate this kind of thing, that the biomass we sourcing is a byproduct. So that means that the majority of the wood in a given forest that's harvested is going into other things besides energy and besides CDR. The other thing we said that I think is really critical here is you need to know what the most likely counterfactual is. So again, waste, not really a thing. The chances that that pile of biomass is just going to get burned is pretty low likelihood, and there's a decent chance that something else is going to happen to it, that's fine, but you need to know what that most likely counterfactual is, and at least try to account for it in your carbon math.

Shayle Kann: For me, the second you get into counterfactuals, and there's lots of places in carbon world where counterfactuals are a thing, but the second you get into counterfactuals, it starts to get messy. It's never easy that once you start talking that way,

Bodie Cabiyo: And the reality is that all biomass has a counterfactual. Even if that counterfactual is decay, that still means the pile of biomass is going to sit there for several years before it's fully decayed. And I've said this a few times, but there are multiple tricky things we'll have to solve. The one of counterfactuals, I think is probably the most wicked problem to solve, especially as we get into that world where you have this big supply-demand imbalance. And frankly, it's going to take a lot of work. It is a wicked challenge, and I think that if you're working on biomass CDR and you're not thinking about counterfactuals every day, you're probably fooling yourself, or you have a really easy case that's going to get harder in the next couple of decades.

Shayle Kann: All right, wicked, indeed. That's a great way to wrap it up. Bodie, I really like this report. I think it's important. I see a lot of novel ideas around biomass-based CDR, and every one of them scares me specifically because of the question of where's the feedstock going to come from? How is it going to scale, and are there going to be a bunch of negative side effects when that happens? So I think the more that we are able to define how to do it right, the less likely it is that we are going to do it wrong. So I appreciate that you're taking the charge on that, and I appreciate your time today.

Bodie Cabiyo: Yeah, absolutely. It's been a pleasure. And the last thing I'll say is that we post this report, put a lot of work into it, got to talk to a lot of really, really smart people. And the thing that I've said over and over again about this is that this is version 1.1, and we're kind of building the plane as we're flying it. We need to fly the plane, we need carbon removal solutions that are going to scale up, but that means that we have to be willing to learn along the way. And this is very much an exercise in learning. So I'm looking forward to revising this and building better frameworks to constrain how we source biomass.

Shayle Kann: Dr. Bodie Cabiyo is a senior forest scientist at Carbon Direct. This show is a co-production of Latitude Media and Canary Media. You can head over to canarymedia.com for links to today's topics. Latitude Media is supported by Prelude Ventures. Prelude backs visionaries, accelerating climate innovation that will reshape the global economy for the betterment of people and planet. Learn more at preludeventures.com. This episode was produced by Daniel Waldorf, mixing by Roy Campanella and Sean Marquand, theme song by Sean Marquand. I'm Shayle Kann, and this is Catalyst.

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