Today, Keith sits down with Ross and Christophe to share his path to the study of soil carbon sequestration. Keith explains what happens when we convert land for agriculture and what we can do to recover the lost carbon inventory. He offers insight into COMET-Farm, discussing how the tool’s models quantify changes in soil carbon and greenhouse gas emissions.
Full Transcript
Alexsandra Guerra: You’re listening to the Reversing Climate Change Podcast by Nori, the world’s first carbon removal marketplace. Here are your hosts, Ross Kenyon and Christophe Jospe.
Ross Kenyon: Hello, welcome to the Reversing Climate Change podcast with Nori. I’m Ross Kenyon here with Christophe Jospe and Paul Gamble. We just finished Reversa Palooza. We’re at the Waterfront Marriott in Seattle overlooking some clipper ships that are about to go around the world in some race. So, I’m looking out the window enviously on that. Yeah, it was a great, great conference. We’ll have another podcast that discusses it in detail. We have a special guest with us here.
Christophe Jospe: I feel very fortunate to have actually one of the panelists, our last panelist, Keith Postgen, who is a professor at Colorado State University in the Soil Sciences Department. And we like to start our podcasts out with really understanding people’s story and how they got to where they are and kind of connecting the dots of what that has to do with Reversing Climate Change. So, Keith, how did you get started in what you’re doing?
Dr. Keith Paustian: That’s a good question. That’s a fun one. I grew up in Colorado and I really loved the outdoors. And when I was going to go to university, what I wanted to do more than anything else was to be a forest ranger. The reason I wanted to do that is I didn’t want to live in town. I wanted to live up in the mountains with a cabin on So, I went to Colorado State University. I started off in forest sciences and I liked it. It was a lot of fun. But somewhere along the lines, I actually left school and went on a year-long bicycle ride in Europe.
After about, I guess, about seven months, I was by myself and I ended up in Norway. And I met some people there. I really liked it. And I was lucky enough to get a job as a lab technician in Norway. And I ended up staying there for two years and learning Norwegian and doing all kinds of cool stuff. I eventually came back to the U. S. I finished my master’s degree, but then instead of being a forest ranger, I got a chance to go to Sweden, which I wanted to do because I had previously been in Norway.
So I went to Sweden, worked on my PhD.
Unknown speaker: Yeah, you’re not that old.
Dr. Keith Paustian: The beginning of sort of the whole global change research community and stuff like this. And I was lucky. The Swedes have always been, you know, pretty big internationalists and stuff like this. And actually, Bert Bolin, for example, was really the president. I was a person that more or less started the IPCC, the Intergovernmental Panel on Climate Change. And he was a Swedish scientist. And I, you know, had the opportunity to sort of get my feet wet a little bit in the climate change community. And then I came back first. There was a lot of interest at the time on land use systems.
And gee, are land use systems sinks or sources of carbon? And they’re much trickier to try to understand what’s happening in terms of carbon and so, I was interested in solar organic matter dynamics in that area. And so, it was really fortunate to be working in that area when kind of the world opened up their eyes to say, gee... Climate change and greenhouse gas emissions is not just about driving your Hummer around burning lots of gas, it’s also how we use the land. And in particular, there was a lot of interest to say, can we manage our agricultural systems and our forests in such a way?
In such a way that we increase the carbon that’s stored in soils, which is, you know, you want lots of carbon and organic matter in your soils is a good thing and if you can essentially encourage that, then you’re in effect removing carbon dioxide from the atmosphere.
Christophe Jospe: And that’s the dream. That’s what we want to do here at Nori. And that’s the kind of behavior that we’d like to drive. I’d like to pick up on a couple of things that you talked about, talking about the carbon and nitrogen cycle in arable lands. And today, if we look at arable lands as a whole, doesn’t look very good. Our practices are leaching nitrogen into our waterways and releasing way more carbon into the atmosphere than it’s taking in. First of all, what’s causing that? And what are the things that can be done that can shift that cycle?
Dr. Keith Paustian: The biggest effect is with converting lands from their native ecosystems, and that could be a forest, it could be a prairie, it could be a wetland, into a system that you’re managing for crop production or livestock or growing cotton or lots of things like that. And so, one of the things you’re doing when you convert a native ecosystem into an agricultural system is you’re changing the carbon cycle. So, you’re doing a couple of things. You’re obviously changing the vegetation, but for one thing, you’re taking off a product now, right? And you’re disturbing the system.
You’re tilling, you’re doing different things. And as a consequence, some of that natural... Carbon capital that you had in the soils and in the biomass and those native systems are lost. So you’ve reduced the carbon inventory on those lands. Things have gotten a little bit better than they were, you know, a few years ago in the sense that there are... There are more conservation practices probably being utilized now than there were say back in the 1960s and 1970s but we still have a ways to go and so we’ve got to do things like croppling systems that have a plant on the ground as much as possible.
We want to avoid a lot of intensive soil disturbance which tends to accelerate the decomposition and the loss of the organic matter. We want to reduce soil erosion. Those kinds of things. And we want to get a much more efficient use of nutrients. So we want to grow lots of food. Plants need nitrogen. So we add nitrogen fertilizers and that’s kind of somewhat unavoidable. But we want to utilize Utilize those inputs, utilize that nitrogen fertilizer as efficiently as possible so that less of it leaks out, goes down to the waterways, causes pollution.
Less of it goes into the atmosphere as nitrous oxide, which is quite a powerful greenhouse gas. So, there’s a lot that we can do to improve our management practices. And if we can improve our systems for growing food and fiber, we can actually recover the Potentially a significant part of the carbon that was lost historically when we converted native forests and grasslands into agricultural production.
Christophe Jospe: I’m excited by that prospect. And I think it seems as if the USDA on some level has bought into that through funding things like Comet Farm. And we’ve got, we kind of hate acronyms, but NRCS, that’s the National... Natural Resource Conservation Services. Okay, I wasn’t sure on the S.
Unknown speaker: Chris, can you also define USDA?
Christophe Jospe: The USDA is the United States Department of Agriculture. What really inspired me about the Comet Farm tool is that here we have farmers who are looking at things in terms of what can I do from the conservation side of certain practices where maybe the USDA will give me a grant or Or maybe actually this will help me grow my crops more efficiently or save money on inputs or whatever reason. And what that enabled scientists like yourself to create models based on these practices which allow estimations of carbon and nitrogen and all other sorts of pieces of the equation.
Can you talk to us a little bit about kind of how that works and maybe the genesis of Comet?
Dr. Keith Paustian: Sure. You know, farmers are typically really know their land. They know how it behaves. But what they’re really good at and what they’re most focused on is their crop yield, right? They already know and can recognize crops. That’s kind of what’s happening on the land with respect to their crop growth and things like this. Now, you know, greenhouse gases and soil carbon, that’s a little bit of a harder thing. You know, you can’t just walk out in your field and get an idea, oh yeah, it looks like I’m releasing too much nitrogen.
I’m looking down and it seems like my carbon stocks are increasing. It’s not that easy. So we need to develop decision support tools that combine data on a variety of things on different data sources. Soil maps and climate data, but also remote sensing and information that the farmers themselves can put into the system, if you will, that describes their management and then use that together with models that can make predictions. So what Comet Farm is, it’s a web-based tool that is really designed to do a state-of-the-art model-based quantification of soil carbon changes and greenhouse gas emissions, as well as a number of other things we’re now working on, on water use and water quality and such.
Basically, if the farmer can provide the detailed information on their management, then they have a tool that they can actually use without being an expert, without being a scientist to get really a state-of-the-art estimate of how their management is impacting things like soil organic carbon or greenhouse gas emissions.
Christophe Jospe: And why is soil organic carbon a good proxy for the state of your soil and the health of the soil? Yeah.
Dr. Keith Paustian: Because, well, for several reasons. I think two main reasons. One is the, you know, soil is a living system. So, there’s literally billions of bacteria and thousands of miles of hyphae of fungi in just a teaspoon of soil. And so, soils are complex living systems. And Most of the organisms living in that soil, they consume organic matter that is derived from the plants as their food source, if you will. You need to have organic matter inputs from... So, because it’s the food source for the life in the soil, that’s one really important reason that solar organic carbon is vital.
But the other thing is that together with the organisms, organic matter is really important for the structure of soil, for the physical nature of soil, how much porosity and the size of... Just mineral matter or organic matter, it’s also empty space, right? It breathes. So about half of the soil volume is actually made up of pore space and that pore space needs to be occupied by water because plants need water. The soil holds the water, releases it, but also air. So we have to have soils that have good aeration for plant roots.
They require oxygen to respire just like we do. The point is that if you have abundant organic matter in soils, the physical structure of soils is favorable for plant growth and for soil health. So, it’s really kind of a keystone attribute of soils.
Christophe Jospe: Great. So, as I try to dig into this a little bit, there are a lot of different soil types and there are a lot of different soil types at different stages depending on how deep you go and depending on where you are geographically. When you say you have a sophisticated model, it’s able to look at each specific soil type and tell me how sort of the interactions of that soil type might affect a certain bioregion. Is that more or less correct? I guess, get us into the weeds, Keith. How does it all work?
How do the different soil types interact with each other? What are kind of the big unanswered questions that, you know, I’d imagine there are many that we want to have more resilience to better understand these soils so you can make better predictive models?
Dr. Keith Paustian: So, if you think of soils, again, soils are these living systems, but they’re also derived from different what we refer to as parent material. In a way, that makes sense, right? It’s where did the soil come from? Soils... Come ultimately from some kind of rocks that are broken down over time into finer and finer particles and then there’s processes of something that’s called chemical weathering which really just refers to changes in... So, depending on the kinds of rocks that soils were derived from, for example, if you So, an ancient limestone reef that has now been lifted up on the land, it has a very different chemistry and a different, you know, soil development than a soil that might have been derived from, say...
Say volcanic ash or something like that was deposited. So those different kinds of parent materials. And then as you change climates, if you’re in the tropics, it’s warm all year round and if you’re in the humid tropics, there’s lots of So, over years, over thousands of years, tens of thousands of years, even millions of years, the soils change over time because of the biology and the chemistry. So, soils in tropics are older soils that... Some of the minerals have been leached out over time, whereas if you go to a cooler region where those chemical and biological processes are slower, then soils are sort of younger and less transformational.
So, those are the kinds of things as you go globally, you get very different chemical and physical properties of soils that co-vary with climate. But of course, climate also affects the organisms in the soils. You know, if you put your food in the refrigerator or you put it in the freezer, it’s okay to eat, you know, two or three weeks later because the microbes that are there with your food are not very active. So, they’re not decomposing it whereas if you leave it out on the countertop. So, climate and soil types are the things that add the kind of complexity and richness to the variability we see in ecosystem types and in how much organic matter we find in the soils.
Christophe Jospe: Great answer. So, you were just at Reversa Palooza and... I believe you were one of the people who raised your hand. Actually, everyone raised their hand, I think, when I asked a question, is there enough capacity on Earth to store all the excess carbon dioxide in the atmosphere? Do you still believe that’s true?
Dr. Keith Paustian: There is enough capacity on the Earth. I would say there’s, I don’t think we can take all of the carbon dioxide that we want to remove from the atmosphere and only put it into soils, but we can take a substantial So, if we either take and inject CO2 deep, you know, several kilometers down and... And even more so, if you start looking at carbon mineralization that one of the speakers who was talking about minerals that can essentially take up the carbon and change their chemistry, there are definitely enough minerals. You know minerals available on earth that can take up that carbon so yeah we can through various means there’s enough space we don’t have to launch the co2 into outer space to get rid of it we can put it back into various reservoirs.
Christophe Jospe: That’s my old idea it’s the third podcast this has come up on tube to space. And I’m glad that we don’t have to do that because I do think that would be very energy intensive. And as Nori kind of looks far and wide at all the different options to remove carbon from the atmosphere and put it in places that, first of all, is ready to start putting it in. And secondly, when you do that creates all these additional benefits from doing that activity. So when we increase the soil organic matter, we also increase the amount of water in the land, which to me tells a very positive story as...
Yeah. Yeah. You’re seeing much more productivity from your crops. You’re saving money on the inputs that you don’t need to put into it. And so, from our perspective, we want to create one additional way for farmers or growers who are doing this certain activity to get paid. So, from my perspective, there are a lot of kind of pushing, forcing mechanisms to make all this happen and we’re optimistic about it happening. But I want to kind of go negative. What’s stopping this from happening? What’s slowing it down? And what are the sort of hurdles...
Dr. Keith Paustian: I would just, before I answer that though, I would just amplify what you said a moment ago that the great attribute of soils and of soil carbon sequestration is two things. The most important of which is what we’ve talked a lot about is that, you know, it improves the ecosystem function. It improves the living systems that we’re dealing with. And people talk about soil health and I think that’s crucial. And the other part of it is, you know, we know how to do it. There’s technologies available and it’s something that can, relative to some of the other mechanisms for carbon dioxide removal, it’s less expensive.
So it’s a natural place to start from that standpoint. So I think there’s several things though is that, you know, farmers don’t always do necessarily the optimal, you know, ecologically best or the most favorable carbon sequestering practices. And some of that can be due to, you know, the technology packages that they have available that their people that they work with, whether they’re companies or crop consultants, they may not necessarily, you know, be thinking of that so much. Their primary way of thinking is still their net returns and sometimes in the short term and their crop yields.
And so, to some degree, it may be constraints due to sort of education outreach, you know, and it can be cultural differences that maybe that a farmer just really likes seeing a clean tilled field during the wintertime because that’s what grandpa had. So, there’s issues like that. But I also think there are instances in which for a farmer to implement a better practice, you know, it might cost them a little bit more or it may involve a little bit more risk. The farmers, they try to avoid risk, they try to avoid, they try to minimize their costs where possible.
So in some cases, they may not see it as rational or economic for them to make these changes without making Deriving any sort of tangible benefits from it immediately. So there may be instances, and I think that it can be often the case, that why not reward farmers financially for providing valuable services, whether it’s carbon removal, whether it’s cleaner water or whatever. And if they are incurring some additional costs, then that should be something that can be compensated for.
Christophe Jospe: I’m extremely excited about this opportunity and this possibility. And I think one of the things that we hope to enable is the kind of data which can indeed be verified and create the sorts of digital applications. And also feeds into the sorts of information which farmers already have or need or want to have more of that help them make growing decisions, which clearly need to come front and center. We touched on a number of kind of challenges and I think that’s kind of one side of the puzzle. I mean, the other is weather happens and it’s weird and that sometimes takes priority.
And you also... Talked about sometimes you have consultants giving certain information to farmers and the consultants might be incentivized in a certain way so the information the farmers are getting is not necessarily what’s in their best interest but is in the best interest of making a profit on the farmers or squeezing them in a certain direction. Probably another dynamic. I want to kind of bring this back to Nori and to understanding the data that Comet Farm creates and kind of the opportunity that as that data is there, that allows us with some kind of certainty to say, okay, indeed, this ecological activity happened.
And here the way we start is by saying this carbon removal activity happened. What information can you take from a model that gives us something where we can say, this is good enough. And by making it good enough, I know also the things that can make it better. And also, by doing this, this feeds into the kind of broader network of information that works for everyone and first and foremost works for the person who is managing that land.
Dr. Keith Paustian: You know, one thing that is really working on our favor here is I think there has really been a technology revolution going on in the last several years in agriculture in terms of things like precision agriculture, in terms of Integrating remote sensing from satellites or from drones and other kinds of observation systems and machinery that is measuring changes as it moves across the field. I guess the Point is now that there’s really been this development of technology, of software, of systems, of databases. It’s all kind of coming together now. And I think so there is an opportunity to leverage this.
These advancements in technology to kind of fine tune some of those approaches so that they more directly address questions about soil carbon and greenhouse gas emissions or other kinds of ecosystem services. So yeah, I think that’s now what we’re on the cusp of doing to really provide the Yeah, really good technology to farmers so that they can assess their opportunities and they can make forecasts about the outcomes of the changes in management that they might want to do or they might want to participate in a program. I think there’s certainly some work to be done to put them together.
There’s an advancing and there’s a pretty rich body of scientific knowledge. You know, people have been interested in soil organic matter dynamics for many decades, if not hundreds of years. So, there’s a pretty good scientific basis to start from. But that being said, it’s a complex subject and there are Certainly need for new research and new observations. But the science is, I think, is advancing pretty rapidly to really understand the behavior of organic matter and soil and how to increase it and how long it sticks around. And, you know, we’re at a good point now to really make some fundamental improvements in how we manage our Yeah.
Christophe Jospe: Great answer. I just give you one final question. You talk about all these advancements which have been made. You’re talking about precision agriculture, which I’d actually like you to define, but that’s not my question.
Unknown speaker: Can you define that quickly? We’re hearing that phrase a lot.
Dr. Keith Paustian: Yeah. Precision agriculture is you know the variability within your field so that you’re understanding that your field is just not the same from one end to the other. You’ve been able to map So, if you have that knowledge and you use so But it’s using GPS type technology and remote sensing and this sort of thing. The farmer, instead of applying, you know, 100 pounds per acre of nitrogen everywhere can say, gee, this part of the field needs 120 pounds and this part of the field only needs 60. You’re tailoring your management more precisely to the actual system that you’re managing.
Christophe Jospe: Great. Yeah, and that really excites us at Nori because when we’re talking about precision agriculture, we’re talking about many Internet of Things devices which give better data into a system which can create credible carbon removal certificates. Final question. You said great advancements in the field. There’ve probably been maybe some myths or misnomers about soil carbon. What would you like to dispel?
Dr. Keith Paustian: Yeah, that’s a good question. I mean, you know, some of the myths have been dispelled. I was working, you know, I guess a couple of decades ago with the Intergovernmental Panel on Climate Change, working on greenhouse gas and solar carbon imports. And I think that’s what we’re talking about. We can’t manage it. We can’t really try to develop policies that would utilize soils as a carbon sink because we simply can’t manage, we can’t measure soil carbon. But I think those kinds of misunderstandings that existed today. Those have gone away now, I think, within the policy community.
Certainly there’s always myths and misunderstandings. The general public, I think, is getting more and more attuned to and understanding the importance of soil. And I’m pretty optimistic going forward that interest is going to continue to grow and the acceptance that we can focus our thinking on soils in a multitude of ways to really try to improve the planet.
Christophe Jospe: Hopeful thoughts and we’ll leave you there. Don’t want to make you miss your plane when you fly back to Colorado. Thanks, Keith.
Dr. Keith Paustian: Thank you.
