In this week’s science-focused episode of Carbon Removal Newsroom, hosts Radhika Moolgavkar of Nori and Holly Jean Buck of the University at Buffalo are joined by co-host Dr. Jane Zelikova, executive director of the Soil Carbon Solutions Center and joint faculty in crop and soil science at Colorado State University.
This week we’re discussing new research which explores the relationship between geology, climate, and weathering rates across the continental United States, as well as an opinion piece in the journal Global Change Biology, arguing that biological processes will also affect the carbon removal potential of enhanced weathering.
Full Transcript
Announcer: You’re listening to Carbon Removal Newsroom, a weekly show about current events in the world of carbon removal, from technology and innovation to policymaking and job growth. Brought to you by Nori, the carbon removal marketplace.
Radhika Moolgavkar: [music] Hello everybody and welcome back after a little Thanksgiving break. I hope everybody enjoyed their time with family, friends and maybe COVID sort of normal. Today we are doing our science episode. So as usual, I have Dr. Jane Zelikova, Executive Director of the Soil Carbon Solution Center and Joint Faculty in Crop and Soil Science at Colorado State University. Jane, nice to see you.
Jane Zelikova: Hey, thanks. Hi everyone.
Radhika Moolgavkar: And then, as always, Holly Jean Buck, Assistant Professor of Environment and Sustainability at the University at Buffalo and a newly published author. Hello, Holly.
Holly Jean Buck: Hello.
Radhika Moolgavkar: At the end, I want you to give us, as part of the good news, a little bit, the title of your book and a little news on that too, please. And then, as always, it’s me, Radhika Moolgavkar, Head of Supply and Methodology at NORI. So today we’re gonna be talking about rock weathering. Our first topic of conversation is a new paper that came out discussing mapping the US’s rock weathering. So for those of you who don’t know, and I’ll be honest, I’m not super up to speed on all this stuff.
So I’m looking forward to hearing what Holly and Jane have to say. Silicate materials covered 90% of the earth’s crust. And when rocks made up of silicates break down, When they interact with heat, water, and the atmosphere, they can sequester carbon dioxide from the air. So they’re a natural source of CDR. And it results in roughly one gigatonne per year of carbon drawdown around the globe today. And just like forests pull down CO2, the rocks and minerals do too. So it would seem natural to try to elevate this and make it a more of a manufactured potential process that humans can use to draw down carbon dioxide.
So with that, there’s been a lot more study and a lot more interest in this area. And so there was new research which explores the relationship between geology, climate and weathering rates across the continental United States. And this has implications of how these processes can be enhanced, can use enhanced weathering to speed up carbon removal. Last month, researchers from the Lawrence Livermore National Lab, that’s a bit of a tongue twister, A U. S. research facility published a paper, Rock Weathering Controls the Potential for Soil Carbon at a Continental Scale. With that, I will have Jane maybe give us a brief overview of what the paper was about, the model they talked about, and what the researchers were trying to answer.
So Jane.
Jane Zelikova: Yeah, happy to. So folks at Lawrence Livermore, the study was led by Eric Slaserov, who is a researcher, postdoctoral researcher. So what they did is they developed a statistical model that linked the relationship between something called the poorly crystalline minerals or minerals in the soil, the abundance of these minerals and linking that abundance to weathering rates and work using the model to estimate the weathering rates based on this kind of like empirical relationship between the kinetics of silicate, silicate weathering. Silicate is a mineral that it comprises many rock kind of formations and looking at the relationship between silicate weathering and soil organic carbon.
Specifically what they were interested in is looking at kind of like soil characteristics, soil water dynamics, the distribution of these kinds of soil minerals across the U. S. and then looking at the distribution of soil organic carbon across the U. S. and climate variables. So what they did is they were able to use this kind of mechanistic statistical model. So it’s not a biogeochemical model. It’s a statistical model to find specific geographic areas where the climate and the primary mineralogy, the type of kind of rock that is weathering in that area, coincided.
So if you get really good climate and really good kind of mineralogy to create optimal conditions for these large PCM or poorly crystalline mineral pools. And so where you have these large PCM pools, you have the potential to have a relationship between the minerals in those pools and soil organic carbon.
Radhika Moolgavkar: And where did they end up finding that this would be most, there’s the most CDR potential in the U. S. , what areas of the country?
Jane Zelikova: So they didn’t frame the paper around CDR specifically, although some of the implications of their work have clear CDR benefits. So they found the strongest correlation between these kind of minerals and soil organic carbon in what they called enhanced weathering zones. And those tended to be zones that are either coastal, so you need a lot of moisture, or montane regions in the western U. S. , so kind of along the coastline. Also post-glacial landscapes in the northeast and the upper Midwest, again, where there’s a lot of soil moisture and a lot of rainfall.
The weakest correlation was in kind of flatlands or low relief areas and also humid areas that are really highly weathered. So the Southeast, so where the soils are really old and weathered and relatively flat landscapes. And they also found really low potentials and weakest correlations in arid climates like where I live in the Western US. There just isn’t enough moisture to really drive this process.
Radhika Moolgavkar: So Holly, and then I’ll pitch it over to you too, Jane, but from kind of the perspective of carbon removal, because you’re right, Jane, this is all about, this was about rock weathering. What is the significance of these findings and what maybe excited you about these findings or disappointed you about these findings?
Holly Jean Buck: I mean, I wouldn’t say that this was like a paper that excited me one way or another. It was like, you know, one more Moderately useful modeling paper. What I’m going to get excited about is when I see more field trials reporting how this stuff works in the real world. Another thing people should keep in mind about enhanced weathering is that, while I’m sure there’s some areas in the U. S. that would be good, the most suitable regions tend to be tropical areas that have high humidity, rainfall and temperature, and preferably acidic soils.
So I think, you know, a lot of people are looking to, you know, these tropical regions in terms of where this technique would be used.
Radhika Moolgavkar: I want to table that thought about the tropical regions and come back to it. But Jane, what was your impression of the paper and its maybe potential impact on carbon removal?
Jane Zelikova: Yeah, maybe similarly to Holly, I can get only so excited about a geologic paper where my expertise in geology isn’t very strong. But I do think there are a couple of things that are really useful that we can take away from this paper. One is that it’s another tool to help us predict potential for soil carbon storage, like what geographic areas to focus specific interventions in. That’s one of the things that I think is kind of needed in this space is just like regionally figuring out where to invest resources, time, research, et cetera, and then focus on doing demonstration trials, et cetera, in those areas.
And I think in this paper, what they have done is given us kind of a template for where we can look for these additional research opportunities or field trials, et cetera. And the next thing is that they kind of an obvious takeaway for me is that a small change in the mineral abundance of these key like sort of minerals, including silica, can alleviate some of this kind of reliance on PCMs. So we’re thinking about like, if you have really highly weathered soils, I think it’s important to note that this kind of rock weathering is something that’s happening in nature already at very slow rates.
So this isn’t like a new discovery. We’ve known that the Breaking down of rock has been like a really important process that has actually altered climate in the past and just happens at a really slow rate. So one of the big things that people are trying to do now is speed up that rate in order to have this be an actual climate intervention. So two takeaways, again, like figuring out where these opportunities exist regionally and focusing resources and efforts in those regions. And kind of getting a handle on how much a small intervention can potentially lead to soil carbon sequestration.
Radhika Moolgavkar: So Holly, you were mentioning that this is probably best used in the tropical south. We’ve talked a lot about the unfair burden like the south part of the hemisphere has taken in terms of climate change versus their impact. How do we go about, do you think, designing studies that ensure that the tropical south, the benefits that they can provide because of their soils also benefit their communities and we do it in a meaningful way. Because when I hear this, I think of iron fertilization. It makes me think of spraying stuff in some place and it makes me anxious, honestly.
So do you think that’s an unreasonable reaction? I ask you both. And two, how are we going to move it forward in a meaningful way when maybe the best places are places that have been unfairly taken advantage of in the past?
Holly Jean Buck: Well, you know, we do already spray a lot of things on our fields and now we have a population of 7 billion, which we wouldn’t be able to support without all the things we’re putting on our field. So, I mean, so I wouldn’t like write it off on kind of that kind of vibe. I do think that, you know, it’s notable that we have an infrastructure too for distributing materials like fertilizer that I imagine Could be purposed for this. So that’s both good and bad, right? What we want to not do is add extra burdens to farm workers, workers on plantations who are already doing a lot of work often in terrible conditions, especially in the global South.
So, I mean, this is like a policy matter, but in terms of the studies, since you asked about research, I think that along with field trials, We should be doing research on what are the actual arrangements in which this would be used, who particularly will be spreading the rock dust? What are these potential transportation chain chains? What’s the life cycle analysis of moving all this rock dust around? What are the public health impacts of crushing up the rock? All of that stuff is stuff we can also start to think about At the same time that we’re doing this really fundamental science, because there’s a lot of basic science needed.
And so, you know, for example, the research group out of Sheffield at the Leverhulme Climate Center, they’re doing social science research, you know, funded by the UK government and probably others, along in tandem with field trials in places like Indonesia, which I’m really happy about.
Radhika Moolgavkar: Are there additional benefits to the rock dust aside from the carbon removal benefits? I mean, Holly, you were talking about like fertilizer, which obviously increases plant growth. Have they seen or has it been tested if there are additional benefits besides the carbon removal potential of rock weathering? Either of you know?
Jane Zelikova: Yeah, and actually this is probably a really good segue to the other paper we’re going to chat about, which talks more about this idea that we already do add rock dust as a soil amendment in many instances because there are limiting micronutrients that plants need for growth. And there are all these studies that have been done that have looked at the addition of things like aluminum, silicate, et cetera, and how they improve plant growth. Potentially help reduce pathogen loads on plants and soil. So there are these benefits that have been recorded in the literature from adding, you know, rock dust or rock mineral materials to soils, especially soils that have been degraded by agricultural use over time.
There are potentially some toxic substances in the rocks that should be measured and There’s like this kind of fine line between adding a little bit that is beneficial, adding a lot becomes toxic. So, you know, exploring those relationships and figuring out what the application rates are is currently a research question, but yes, generally adding these kinds of mineral substances has lots of plant benefits and soil benefits in general.
Radhika Moolgavkar: So, yeah, let’s, since we, you brought it up, Jane, let’s kind of pivot over to that other I guess it wasn’t a paper but opinion piece that talks about the fact that a group of researchers published a piece in the journal global change biology and arguing that the biological processes will also affect the carbon removal potential of enhanced weathering which Jane you alluded to. And that plants and soil microbes can affect rock weathering and that more research is needed to understand how mineralization will work in real biological systems. So essentially they’re arguing that the research so far has been too narrow and has left out an important subset of work before and until we do that in a more Holistic way, we can’t really understand whether rock weathering is as beneficial as we argue it is, or some argue that it is.
So Jane, what do you see as their message to the scientific community about this, about when they wrote this opinion piece? And what do you think they’re saying about weathering as a technique for carbon removal, if you could get that from that opinion piece?
Jane Zelikova: Yeah, what I like about this paper is that it attempts to bring together a bunch of research in kind of what are often more siloed or disparate areas of science. So folks that are working on the relationship between plants and soil and mineralogy, other folks that are looking specifically at microbial communities, how mycorrhizal fungi functioned. And then they also bring in research where it looks at the feedbacks back into plant microbial communities. And so it’s actually a really nice kind of overview of what we know today about this relationship between plant effects on soil chemistry, plant effects on physical soil structure, Microbial effects on plants, microbial effects on soil chemistry, and how that all kind of interacts with silicate minerals that are already in soils.
And so it’s just a really nice kind of review of what we know today. And I think they make a, I would say a compelling, but not a really strong argument that these biological factors should be incorporated into how we model the potential for enhanced silicate weathering. And potential for carbon drawdown. So kind of similar to what Holly said earlier, again, it’s another tool that helps us refine our predictions for these potentials. And the biota are not currently really incorporated into modeling models. I would say generally climate models have a really hard time handling critters and the effect of critters on the carbon cycle.
So this isn’t like a really big news. We kind of know that it’s really hard to incorporate microbial processes into climate models. But I think it’s important that we do that because they affect the rates of weathering in really fundamental ways. And I would say almost drive in combination with kind of climate and water chemistry drive these processes.
Radhika Moolgavkar: And so Holly, what areas do you think we need to focus on before we can really think about enhanced weathering as a credible way of removing carbon?
Holly Jean Buck: I mean, I think that all of this pretty fundamental stuff about how it interacts with biology, I think that there’s a lot of research that maybe hasn’t been done in this space because there’s like little different communities of science, right? So the earthworm people might not be talking to the rock people very often. And this is kind of a new applied thing that nobody maybe had A pressing reason to study as much before, you know, there’s a reason to actually try to apply some of this in the real world for carbon drawdown.
So, you know, anything, anything basic science around this, I think that also thinking about enhanced weathering in the oceans is another important area of research. And it’s also worth noting that there’s some research about mine tailings and enhanced weathering. Mine tailings kind of maybe being an easier thing because the rock is already like processed and maybe ground up a bit. So that could be cheaper. That would have different social implications, I think.
Radhika Moolgavkar: Yeah, I mean, it’s funny you say that because I think what Jane’s doing at her new job is kind of trying to bring together, right? It feels like carbon removal is a whole new approach to science, but maybe I shouldn’t say a whole new approach, but it’s changing the traditional approach to science, right? Very siloed and you have to have a lot of multidisciplinary folks together to really understand the overall impact because nature isn’t a vacuum. And I was also talking to somebody at the University of Washington a couple of weeks ago about the same thing with the oceans.
Like there’s so many, it’s so interconnected that you can’t do it in a vacuum. And I’m hopeful that as Jane and others in the field develop these centers that we can break that mold and move these research projects for farther, more quickly. That being said, How accepted is this technology within like the climate justice community, environmental justice community? Are there similar concerns with this as there are for other types of carbon removal strategies? I’ll start with you, Holly, and then I’ll also ask Jane the same thing.
Holly Jean Buck: I mean, I think I can generalize that nobody really knows much about this. So I can’t speak about really the climate justice or environmental justice communities, although I do think they would be Interested in terms of to what degree this would change patterns of extraction. When the general public has been surveyed on this, there’s been a couple of studies, one of them by Elspeth Spence and others says that it was not viewed as a very distinct concept by respondents. It didn’t produce positive or negative associations compared to like all these other carbon removal or climate response strategies.
And they also suggest that framing it as a soil amendment versus climate change technique might result in different perceptions. Because, you know, people have a kind of a vision of what a sustainable world is. A bunch of heavy machinery and mining and rock processing doesn’t really line up with that. So, but mostly I’d say it’s TBD. Too early to know.
Radhika Moolgavkar: What about you, Jean? What have you been?
Jane Zelikova: Yeah, I was going to say a lot of blank stares when this comes up, even for people who are working in this sort of general carbon removal space. I agree with Holly that the use of heavy machinery and sort of the mining operations and the scale at which those operations would need to ramp up in order to meet the climate, specifically the climate demand, should be considered because, you know, these Aside from like using mine tailings and other kind of industrial waste, if we’re needing to get primary rock minerals back sort of like mined and then ground up and then put on top of soil for the carbon removal, like we need to really make sure that process makes sense from a overall climate perspective that we’re not like sort of emitting more into the atmosphere for the process and for the transmission, you know, transport of very heavy rock materials to the places where they’re going to be applied.
It also has to kind of make sense regionally. So big questions around that, but generally people don’t really have strong opinions about this as a solution relative to many others that there are very strong opinions about in the carbon removal space.
Radhika Moolgavkar: Maybe the good news about this one, this technology is that it is early enough, benign sounding enough that it can, the basic research and other research can happen A little bit under the radar before, you know, there’s a lot of hype around it because I think I’ve said this many times, but I keep saying it like sometimes the hype really outpaces the science and it’d be nice if it was the opposite for once. And I can’t agree with you more about the life cycle assessment of the overall process. And also there’s the appearance of what you’re doing and how important that is to make this a Successful strategy.
Jane Zelikova: I think a lot of questions also about how this works financially for people. Like if there’s a company that’s developing this as a carbon removal solution, and we know that companies like Stripe have invested in enhanced weathering in the past. And so if they’re sort of as a company that’s selling the carbon removal service, but applying rock in an agricultural context with farmers involved, You know, there are questions about sort of like who owns the carbon removal service or who is providing the service, how to distribute the profits. If farmers are getting other like ecological and production benefits from applying these soil amendments, there are just a lot of questions about how to sort of divide the profits, who pays for this as a service that I think will be, are already being worked out in some way, but will become even more pressing as the solution kind of It maybe hits prime time in the next few years.
Radhika Moolgavkar: I think that’s probably just true generically of the carbon credit marketplace, ownership of the carbon credit, who gets the monetary benefit from it, who gets to claim it on their accounting. It’s a very vast and open area that I think about pretty much every single day in my job and have not come up with any great solutions. Holly, what do you see as like the next steps in getting this technology outside of the science piece, getting this technology out there, primetime ready, as Jane said, and, you know, beginning the use of it?
Holly Jean Buck: I mean, I think that the next steps are just investing more in the science. I’m very concerned that issuing credits without good methodologies is getting ahead of things. And I’ve seen a little bit of that lately.
Unknown speaker: Just a little.
Radhika Moolgavkar: What about you, Jane? What are you thinking?
Jane Zelikova: As always, I agree with Holly. And I think this is not just an area of fundamental research that we need to do, but a really exciting one. Because it brings together so many different disciplines into one space and I mean I dream of this for my job like that I would eventually be located in a building with folks that are working on sort of like geology and soil carbon and agriculture and social science and we all could like hang out in a building together and have lunch together and be able to like come up with solutions we’re not coming up with on our own and so I think We have an opportunity to kind of drive research in this more kind of diverse transdisciplinary way in this space because it is relatively new.
It’s not so new. I mean, geologists have been working on this for a long time. A lot of the like basic principles of how weathering works and where the carbon ends up have been well worked out and modeled, but they just haven’t been modeled and worked out in a way that is focused on like kind of immediate application. And that’s kind of what we need to do for climate is we need to develop and apply solutions at a faster pace without skipping the steps of actually quantifying things and just issuing credits based on, I guess, wishful thinking.
And so, yeah, lots of cool research to do. This is an area to keep an eye on.
Radhika Moolgavkar: Where are the leading institutions doing the research in rock weathering? Is it just generically in the United States? Is it in Western Europe? Or all over the world, where should we look?
Jane Zelikova: I attended this like conference last summer. It was a virtual conference, all focused on enhanced weathering, specifically of olivine rocks. And a lot of those researchers were all European and it was kind of a trip to be in a European conference. Things are really kind of, science is different in Europe than it is here. Some of it in good ways, some of it in bad, but yeah, I think Europe is doing a lot I don’t know, specific institutions, probably Holly does. Folks in Canada, University of British Columbia, University of Washington, Princeton.
Yeah, those are kind of the main ones I can think of.
Radhika Moolgavkar: Well, always glad to hear a shout out to my alma mater, University of Washington. So Holly, any other thoughts to add to that?
Holly Jean Buck: Just that I think that the UK and also the German government have done a pretty good job funding interdisciplinary research in this and That’s why there’s a lot of scientific papers coming out of those areas.
Radhika Moolgavkar: Well, then we will just keep our eyes sort of turned to the east and hope that they keep us moving forward on all things weathering. With that, I’m going to turn it over to Holly for some good news, though I am going to rudely inject my own good news, which is she published a book. So we want to hear all about that and then whatever else she wants to tell us. So Holly, the floor is yours.
Holly Jean Buck: Well, I’m going to tell you some good news that relates to the topic of my book. And some listeners may disagree that it’s good news and we can have productive disagreements because I’m all about productive disagreements. So there’s been a couple of plans for energy, fossil fuel energy export facilities in the U. S. that have been canceled. So there In Oregon, the Jordan Cove project that was going to be a liquefied natural gas export terminal, the first one in the West Coast in the lower 48. That was, you know, the Canadian Energy Company called it quits basically on that.
People have been fighting that for a long time. Also recently in Plaquemines Parish, Louisiana, there is going to be a $2. 5 billion oil export terminal. That announced that it would be canceled. There had been environmental justice groups fighting that for a long time as well. So I think that these things are good news. And my book is called Ending Fossil Fuels, Why Net Zero is Not Enough. It’s actually a fairly nuanced read despite the strong activist sounding title. And, you know, it says that we have to get Realistic about the challenges of ending fossil fuels, like we have to go beyond this slogan of just ending it and like celebrating every time a facility Is closed because we’re still reliant on fossil fuels for over 80% of our energy.
And if we just kind of have an unmanaged decline, it’s going to be a mess. So the book talks about like how to be thoughtful about this project, which is a multi decade project of phasing out fossil fuels.
Radhika Moolgavkar: And Holly, that is wonderful news. Congratulations, like I said. And curious if you’ve gotten any pushback from parts of the environmental advocacy community for maybe providing a more nuanced perspective, or are you getting pretty much just wide accolades, which I’m sure you deserve?
Holly Jean Buck: Honestly, with this book hitting right at kind of the time of the cup in Glasgow, I think maybe people have like a bit of fatigue from that whole process. So, you know, I wouldn’t say that I’ve received like strong reaction either way. Although people have found people have been like, I’m so glad you wrote this because I can assign it to undergrads and we can read it together and it’s readable for like multiple audiences. So that’s the feedback so far.
Radhika Moolgavkar: That’s a huge compliment, Holly. I’m looking forward to reading it, and maybe I’ll get my 15-year-old daughter to read it too, though. Just a little bit under an undergrad. Well, with that, I will wrap the show up. As always, thank you both Jane and Holly for being on the show. And Jane, since I won’t see you until 2022, have a wonderful new year and holiday.
Jane Zelikova: Thank you. Same to both of you. Maybe I’ll see Holly. Hopefully I do. But if I don’t happy. Yeah. Goodbye. 2021. You’re definitely a mixed bag ready for 2022 to come around.
Radhika Moolgavkar: I kind of remember last year, everybody celebrating 2020 coming to an end. And I was like, I don’t know. 2021 seems a lot like 2020. And right now 2022 is feeling a lot like 2021. So I’m But I continue to be optimistic that we will push through and we will get to a better place. With that, listeners, thank you for listening this week. Next week, we will be doing our policy show and wrapping up for 2021. So I hope you’ll join us. Until then, take care.
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