S1 #3 | Soil: carbon sink and saviour?

S1 #3 | Soil: carbon sink and saviour?

Contents: introduction, guest appearances, further reading, transcript, sources, credits

"We can sequester with regenerative agriculture between 5% of all emissions and 100% of all emissions. That's a big difference"

Whenever we used to find ourselves around farmland, we never paid much attention to the soil beneath our feet. Making this episode will make us think twice next time...

Why? Because, when you dig a little deeper, soil is far more important for carbon storage than you might have imagined. The world's soils hold more carbon than the atmosphere and the world's forests combined - but what potential do they hold for helping our carbon removal cause?

In this episode, we delve into the silent crisis of our soils, and discover the regenerative agriculture movement ready to address it, with a mix of ancient wisdom and novel technologies.

This episode's guests

Many thanks to our excellent guests in this episode:

  • Aldyen Donnelly, co-founder and Director of Carbon Economics at Nori
  • Ben Flock, Head of Transition Finance at Climate Farmers

Want to delve deeper now you've listened to the show? Look no further than the list below of articles, podcasts and other resources. They helped us to learn more about the degeneration and regeneration of soil, and we think you might like them too...

Our Reading List & Sources

NamePublisherPublishing/Release DateSourceSummaryTag(s)Type
September 1, 2020
Regenerative Organic Agriculture and Climate Change
Global Sequestration Potential of Increased Organic Carbon in Cropland Soils
November 14, 2017
Academic Journal
Soil Health Nuggets
A Major Climate Idea Is Based on Some Shaky Science
July 31, 2021
What Can Farmers Do About Climate Change? Dynamic Cropping Systems
February 21, 2017
Soil organic carbon: quantifying and incentivizing its accrual
January 31, 2021
Here come the robots: precision and regenerative farming
April 12, 2021
Adapting crop rotations to climate change in regional impact modelling assessments
Science Total Environment
March 1, 2018
Academic Journal
Soil as Carbon Storehouse: New Weapon in Climate Fight?
March 4, 2014
EU sets the scene for carbon removal actions in farming
July 20, 2021
Fertiliser application rates
Our World in Data
October 22, 2021
Only 60 Years of Farming Left If Soil Degradation Continues
Scientific American
December 5, 2014
Soil Carbon Storage
January 1, 2012
Agricultural Land (% land area)
October 22, 2021
Drax's Towards Carbon Negative Resources
October 30, 2020
An update on Drax's progress towards being a carbon negative energy producer by 2030.
BECCSCorporate pledges
Nature-Based Climate Solutions Are A Key Strategy to Reach Net Zero
Mark Tercek
February 2, 2021
An article from the former president and CEO of The Nature Conservancy on why we need nature-based solutions to reach a net zero economy. He covers the case for, the case against and how companies could "do" nature-based solutions better.
TreesAgricultureCorporate pledges
How supercharged plants could slow climate change
TED Talks
April 1, 2019
How we could genetically modify plants to make them better carbon sequesters
A power company’s potent vision: From neutral to negative emissions
July 9, 2020
Drax Group drastically reduced its carbon footprint by shifting from coal to biomass. CEO Will Gardiner discusses the costs and challenges to scaling up its model.
BECCSScaling up
Carbon Dioxide Removal Primer
Various authors
January 1, 2021
A summary of all things carbon dioxide removal related, written by several experts in the field. An invaluable resource, available as a book or freely available online.
Carbon180 Deep Dives
February 1, 2021
Three-page introductions to the key areas of carbon removal - forests, agriculture, DAC, carbon use and BECCS.
Carbon useBECCSDACAgricultureTrees
A commercialization strategy for carbon-negative energy
Nature Energy
January 11, 2016
Climate change mitigation requires gigatonne-scale CO2 removal technologies, yet few examples exist beyond niche markets. The flexibility of thermochemical conversion of biomass and fossil energy, coupled with carbon capture and storage, offers a route to commercializing carbon-negative energy.
BECCSScaling up
Academic Journal
Is there value in temporary carbon removal?
Robert Hoglund
August 11, 2021
This article argues that temporary carbon removal credits do very little in contributing to solving or slowing the carbon crisis, and offers some alternative strategies (especially for companies) for contributing towards solving the situation.
AgriculturePermanenceCorporate pledgesMeasuring CO2OffsetsCriticism
Carbon removal permanence calculator
Carbon Plan
December 9, 2020
This calculator estimates the upfront costs needed to make a temporary carbon removal strategy permanent over time, and allows comparisons with more permanent techniques.
Carbon cyclePermanenceEconomics
The dirt on soil carbon sequestration
February 1, 2021
Recommended by Sophie Purdom

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Tom Previte 0:22 The other day, when I was talking to a friend, they actually asked me, what is soil? And it really stumped me. I thought, hang on, I need to go back and double check this.

Emily Swaddle 0:32 Basic questions.

Tom Previte 0:33 Basic 101 of a podcast with an episode on soil. And, and so I found myself Googling and I found out that soil contains two parts to it. There's the biotic factors, which are things that actually are living or were living. And then the other part of it is the abiotic factors, things that essentially just are not living.

Emily Swaddle 0:53 Yeah, I guess I never really think about, what is soil? It's just a collection of things. I was thinking in my like language nerd head about the way we talk about soil. Obviously, we refer to it as soil, but also we call it earth, right? Like this is the planet Earth. But with a little E. And the big E/ little e, I feel like they're trying to tell us something like, "save the Earth" is "save the soil"...

Tom Previte 1:18 Maybe it's a conspiracy.

Emily Swaddle 1:19 Well, I think it's like some subliminal messaging to get us to take care of the soil.

Tom Previte 1:24 I like that thinking.

Emily Swaddle 1:31 Hello, listener, and welcome back to The Carbon Removal Show. Today is episode three. I'm Emily Swaddle, and as always, I'm joined by Tom Previte.

Tom Previte 1:40 Yes. And today, as you've probably gathered, we're going to be talking about soil: what it is, how it stores carbon, and all the terrifying things that we're doing to it.

Emily Swaddle 1:49 Cheerful as ever, Tom. So we should probably start with why we're talking about soil.

Tom Previte 1:53 Right? So we kicked off this series talking about nature's most well known carbon sink: trees. And it's kind of the obvious answer, right, to this issue of carbon removal. But nature actually has loads of ways in which it stores carbon aside from trees. And that's all part of the carbon cycle we touched on in episode one. Other sinks include oceans and also soil.

Emily Swaddle 2:14 Right. And that's the topic of today's episode.

Tom Previte 2:17 According to the science journal, Nature, soils actually store more carbon than the atmosphere and all the world's plants and forests combined. So there's lots of talk about.

Emily Swaddle 2:27 Yeah, and we are going to dive into that potential, we're going to look at some of the things that we're doing wrong when it comes to soil care, (Spoiler alert: there's a lot) and we're going to explore some of the things that we could be doing right.

Tom Previte 2:40 And what we really want to find out is if soil can actually be a key tool in our carbon removal toolkit, and if so, what do we need to make it happen?

Emily Swaddle 2:50 We're joined in this episode by a couple of experts. We're going to be speaking to a pioneer of the soil carbon sequestration industry. She has been working in this field, this muddy field for decades. And we have a guest from a startup that's taking a community approach to this issue.

Tom Previte 3:08 Let's dig in Emily,

Emily Swaddle 3:09 Let's.

Emily Swaddle 3:13 Tom, you've already mentioned the huge amount of potential carbon storage in the soil.

Tom Previte 3:18 Yes, and a lot of that scale is down to the sheer amount of soil that covers our planet. It's not only is an important factor in our world ecosystems, it's also the foundation for all of our agricultural land.

Emily Swaddle 3:30 Yeah, and that agricultural land actually makes up 37% of the land surface on Earth. And it's where we have the biggest chance to make an impact on our soils given that as humans we manage that land and work really intimately with it. It's like where human land management meets natural soil processes.

Tom Previte 3:51 And something that we skipped over a little bit when we were discussing trees and forests is that very often those incredible ecosystems are actually cleared in order to make way for agricultural land. Of course, we have a growing population to feed, and so we need to manage the land in a way that it can produce and store.

Emily Swaddle 4:09 Yeah, it isn't actually particularly something I had considered too much before getting into this. But it does make a lot of sense that soil is so great at storing carbon. I mean, as you discovered, Tom, in response to your friend's question, soil contains organic matter, organic matter is mostly carbon... boom, carbon sink.

Tom Previte 4:30 In a nutshell. Yeah. And might I add my friends asked very good questions. So if you imagine, Emily, a side profile of some soil, you've got plants sitting on top, it could be a great big oak tree or some lush grass, whatever it might be, that organic mass is absorbing co2 through the process of photosynthesis. This co2 is then getting broken down into carbon, and that carbon is traveling through the plant into the root system and then dissipating out into the soil.

Emily Swaddle 4:59 A while ago Tom and I had a conversation with Aldyen Donnelly. She's the co-founder and director of carbon economics at Nori, which is a carbon removal marketplace. She's worked in sustainability consultancy, venture capital, carbon markets since the early 90s. And we were so impressed by this conversation we had with her, she just spoke with such knowledge and depth of insight around a whole lot of topics. And she introduced us to the current state of our soils.

Aldyen Donnelly 5:24 Over the last 300 years, well, when we've shifted from sustenance level food production to industrial food production, the soil scientists community estimates that the organic carbon stock and the top 30 centimeters of the soil layer worldwide, is about 50%, what it used to be. And that's the amount of carbon we've released from that that natural warehouse, largely due to what felt like highly productive agricultural practices. The single largest, you know, over time, source of carbon loss was just intensive plowing. And just as a rule of thumb, the more hours or days per year that a field has their soil touching the air, the more carbon you're losing to the atmosphere, all other things being equal. And so when we went to sort of this practice of planting a big single crop for a season, plowing the land, and leaving it fallow between growing seasons, and also in that practice, depleting the soils capacity to support plant growth so much, that every three or four years we had to leave it at fallow, and spent a whole bunch of money applying nutrients to it so that it would come back to the productive... That's all a process of just releasing carbon, and also reducing the soils ability to retain water and other nutrients that are essential to plant growth.

Emily Swaddle 6:54 Topsoil by the way, that's the top 30 centimeters of soil, and it's vitally important for carbon storage.

Tom Previte 7:01 Yeah, and it's super important for agriculture too. Back in 2014, the UN said that all the world's topsoil will be gone in 60 years, if current rates of degradation continue. That's pretty scary stuff. And it's degraded only by deforestation, as we've discussed, but also by modern industrial agricultural processes.

Emily Swaddle 7:21 It makes me think about those, you know, those Greenpeace films like the videos they do, where they show these like, terrifying shots of the rainforest being felled, and all these like big, beautiful trees that just come crashing down and you see like wildlife running for their lives. But what we don't see is what happens next. And that's industrial agriculture. Tom, should we whip through some of the ways in which industrial agriculture causes issues?

Tom Previte 7:46 Emily, I thought you'd never ask. A lot of modern agricultural practices are pretty terrible for soil carbon sequestration, but we want to whiz through four of the bigger ones. You've got plowing, use of nitrogen fertilizers, monocultures, and leaving the land fallow.

Emily Swaddle 8:02 Yep, those four are some of the big hitters.

Tom Previte 8:05 So plowing, it's actually a very common practice in modern day agriculture. And it's a nightmare for the soil carbon sequestration. It's essentially a process whereby the top layer of soil is just like, totally overturned. So you kind of imagined flipping a pancake. And then there's also another process called tilling. Tilling is where the soil is broken up into smaller pieces. It's sort of like running a comb through that top layer.

Emily Swaddle 8:29 Thanks to that excellent visualization, Tom, we can kind of really imagine how carbon is released during these practices. So essentially what happens is that more soil surfaces are suddenly exposed to the air. And that gives bacteria a chance to start, you know, really getting its teeth into all that organic matter and decomposing at a much higher rate than it normally would, because it's got lots more oxygen. And then that decomposition releases that organic carbon back into the air as co2.

Tom Previte 8:58 Plowing and tilling though, as we know, are not the only industrial agricultural practices that have detrimental effects on the soil.

Emily Swaddle 9:05 Right. I've actually been looking into nitrogen fertilizers. There are actually many kinds of fertilizers out there, but nitrogen fertilizer is the most commonly used. Globally in 2014, over 100 million tons were used. Nitrogen fertilizer is undoubtedly effective at increasing yield in the short term, but by replacing soil chemicals with synthetic alternatives, the upshot is that we need to keep adding more and more synthetic chemicals. So the soils natural composition is just degraded.

Tom Previte 9:36 Not to mention the host of other issues associated with the industrial use of fertilizers and pesticides. You've got human health concerns, biodiversity issues, the heavy industrial machinery that is required for this process. There's a lot of that research, so there's loads to read about if you're interested.

Emily Swaddle 9:53 So we've done tilling, plowing, use of chemicals... Tom, can you tell us about monocultures.

Tom Previte 10:00 Industrial agriculture typically relies on monocultures, because it's logistically easier to sow and harvest a huge amount of space if it's all growing the same crop. But as we touched on, monocultures are bad at capturing and storing that carbon. And that crop, the single crop that you grow can drain the soil of key nutrients and leave it pretty degraded.

Emily Swaddle 10:19 And to make up for that degradation of the soil, farmers will often leave parts of their land fallow for a year or a season, which means that there are no crops being grown on it. But they actually might still plow that land. And without allowing other plants to grow there, there's nothing stopping that soil from releasing all that good carbon stored in it. It's really not looking good for industrial agriculture at this point.

Tom Previte 10:41 On top of all of those issues that affect the soil, industrial agriculture also contributes to our emission, pollution, waste problems. That's like a quadruple whammy.

Emily Swaddle 10:54 I've got 99 problems, and industrial agriculture is all of them. It just makes me question how we even got here. When we spoke to Ben Flock from Climate Farmers, he reminded us why the system came about in the first place.

Ben Flock 11:06 I'm not here to bash conventional or industrial farming, because there's a reason for why it has become the way it is now. And if we look at the dynamics of after the Second World War, where people needed to be fed, and people were undernourished, it was at the time really understandable that the focus was on feeding people no matter what. But now we have a food system, which is very confusing because we have we have a lot of food production and also a lot of food waste on one side of the world. And on the other side of the world, we might have undernourishment and people with nothing to eat.

Emily Swaddle 11:40 Ah, industrial agriculture doesn't even do the one thing it's meant to do.

Tom Previte 11:45 And if we're going to get that topsoil back to fighting fit, we need alternatives.

Emily Swaddle 11:51 We do.

Emily Swaddle 11:55 The startup that Ben Flock works for, Climate Farmers, is a platform that supports the transition from industrial farming to regenerative agriculture.

Tom Previte 12:04 Please, please, please tell me this is the alternative we're looking for.

Emily Swaddle 12:07 Well, maybe, or at least maybe one of them. So let me break it down for you. It's based on the ideas of conservation and rehabilitation. It looks at resource management, water quality, and of course, soil health. Things like minimizing soil disturbance (so no plowing, no tilling), keeping soil covered with crops for as long as possible (that's no fallow land), keeping living roots in the soil, growing a diverse range of crops (no monocultures), and integrating livestock. Actually, if you want to dive into that one about the livestock, I recommend the Kiss The Ground documentary on Netflix. Many of these principles that regenerative farmers follow are based on other philosophies of agriculture, like permaculture, agroforestry, holistic management, and a lot of these practices are borrowed from ancient farming techniques, or based on nature's own cycles, you know, often with a bit of a modern twist.

Tom Previte 13:03 It's kind of a combination of old and new, where you learn from the past and I guess adapt to the future, right?

Emily Swaddle 13:10 Yeah, it's true. The term regenerative agriculture was first used by the Rodale Institute in the 1980s, but became more widely known when they released a white paper in 2014, entitled, Regenerative Organic Agriculture and Climate Change. In the summary of that paper, it says, and are you ready for this? "We could sequester more than 100% of current annual co2 emissions with a switch to common and inexpensive organic management practices, which we term regenerative organic agriculture."

Tom Previte 13:43 Did I just hear you say "more than 100% of current annual emissions"?

Emily Swaddle 13:48 Yep, that's what they claim.

Tom Previte 13:50 That's bold.

Emily Swaddle 13:51 Aldyen Donnelly gave us a thorough description of some of these regenerative agricultural practices.

Aldyen Donnelly 13:56 So a lot of regenerative ag is doing a modern, more productive, old fashioned way of farming, where your goals are to have the actual ground covered, not in direct contact with the air as much of the time as possible. So reducing plowing, reducing the time that any field is at fallow, doesn't have, you know, something growing in it. Also, we learned about much multiple crop rotations. Some crops, by definition, tend to leave behind more nitrogen and take more carbon out of the soil. Another crop is the opposite. So we used to plant the same crop every year, which was depleting something that was important. We now know that if we rotate crops with opposite patterns, we're actually building up a healthier soil. So multiple crop rotations, it's not just going to multiple crops, it's what's the order, given what they leave behind and what they take. Then adding cover crops inbetween seasons that's mostly about keeping the soil covered between harvests. Integrating livestock into the crop production practice, so that they are naturally dealing with residuals, getting more biomass plowed, just by the way they operate, into the soil, and reducing the amount that is just naturally biodegrading and going back up into the atmosphere. And you can go on and on and on. Every couple years there's a new idea that comes up that's really good, so it's, it's, I don't know where it ends.

Emily Swaddle 15:27 I once read about, it was actually in a Mexican cookbook, that a lot of traditional Mexican food, kind of much of the cuisine of the indigenous people of that region is based around corn, beans, and squash. And I was reading about how these three crops kind of support each other, both physically and biologically. So with the beans, they're really good for holding nitrogen. Corn grows as a tall sturdy structure, which means the beans can grow up it, because they need that beanstalk. And then the squash, squash is a very wide broad plant that covers the soil. So it's like protecting that soil. And it's like this Holy Trinity, you know, of like corn, beans, squash. That is a traditional ancient farming practice for many native cultures in the Americas.

Tom Previte 16:17 That's amazing. That sounds like exactly the kind of agricultural tradition that regen agriculture is building on. And I also love the new tech innovations that are coming out of this transition things like light tech. So while the past trend in farming machinery has been based on economies of scale with tractors getting bigger and heavier, the future would be about smaller, more nimble machines. And these machines could operate autonomously moving intelligently around the crops, and they would be ultra light to avoid soil damage and enable a major reduction in the application of chemicals. Something that was also really cool, were the sensors that can intelligently recognize a different species of plant, and either zap them with a laser for weed control, or apply a micro droplet of chemicals to a leaf, achieving 99.99% reduction in the volume of herbicides.

Emily Swaddle 17:13 That's pretty fancy. Like a diet robot for each planet.

Tom Previte 17:19 I know. And just to put that into context, a lot of sprayers that we have, at the moment, only achieve about 5% efficiency

Emily Swaddle 17:28 5%?! Like as in, when they're spraying, they only hit the crop 5% of the time? And 95% of the time, it's just wasted. Oh my days. That's ridiculous. On that technology front as well, Tom, there's a lot of data collected on farms these days. So data coming in about weather systems to inform crop rotation, for example, and regenerative agriculture really harnesses that kind of technology too. In some cases, using artificial intelligence alongside the data collection to make processes more efficient.

Tom Previte 18:02 Super cool.

Emily Swaddle 18:04 Yeah, it is cool. With all these practices, there are actually like a lot of potential benefits from regenerative agriculture. And they're pretty far reaching. You know, it's not just about improving soil as carbon sinks, there's also benefits for biodiversity, it can help with pollution problems, it can give more reliable harvest for farmers. There's a lot that it's got going for it. So we asked Aldyen, we said, you know, what does it look like? What does a regenerative farm, if we were to pass one on our little jaunts around the countryside, what does it actually look like?

Aldyen Donnelly 18:38 That's a really good question. And I have a really hard time with it, because one of the complications here is the best way to maintain soil health is it is different in every field, and changes over time. So the answer is there isn't one answer. But certainly, in general, where you used to see a field that was at fallow a bunch of the time, and it was just cropland. If you're now looking at a field that maybe is outlined by trees, and might actually have a row of trees down the middle, and has a few cows walking around making themselves happy, not not many, but you know, doing a lot of control for you, and is harvesting two different crops in a season, and where you hardly ever see (if you're talking to farmers, you know, allowed to say dirt but for me, it's where you actually...) if you're going by everyday, hardly you don't think you're seeing dirt very often then you're in good, in good shape. And if you put your hand down and pulled up a chunk of soil, it's dark and it's full of worms.

Emily Swaddle 19:44 I love that image that Aldyen just mentioned you know that like dark, yummy soil. I have a fun fact now for you, Tom.

Tom Previte 19:52 Hit me.

Emily Swaddle 19:53 There are more micro-organisms in a teaspoon of healthy soil than there are people on Earth. That fun fact came from the US Department of Agriculture. Thanks to them for that one.

Tom Previte 20:06 What a way to worm that factor in there, Emily.

Emily Swaddle 20:10 You're on fire, Tom.

Tom Previte 20:12 A regenerative farm sounds lovely. But realistically how much of a dent is it going to make in the carbon problem? That bold stat from the Rodale Institute that regenerative agriculture could sequester more than 100% of annual emissions is still kind of ringing in my head. Can these kinds of farming practices actually help us reach that large scale carbon sequestration?

Aldyen Donnelly 20:35 If we theoretically say the capacity of the soil we use to grow crops and livestock can be built up to the level what was the carbon stock level it was 300 years ago. And I'm saying while keeping that land in crop production, not by taking it out of production. If we exploit only half of that capacity, they can offset 25 billion tons a year, every year between, for the next 100 years. It's not the whole picture. But it's a big chunk.

Emily Swaddle 21:05 That's another impressive statistic there from Aldyen. You know, she keeps putting these big numbers out there. If regenerative agriculture can live up to these numbers, and keep producing food on that land, I'm in, sign me up.

Tom Previte 21:20 The issue I have is some of the difference in these numbers. We've had competing stats that suggest between half and all of our current emissions can be captured through regenerative agriculture. But then another recent paper that I came across puts this considerably lower at only 2.5 Giga tons of carbon storage versus the 50 Giga tons of co2 equivalents were responsible for each year. We're talking an order of magnitude of difference here.

Emily Swaddle 21:46 Yeah, we can sequester with regenerative ag between 5% of all emissions, and 100% of all emissions. That's a big difference. You know, to me, it really highlights how difficult it is to measure this. And I suppose that's partly because these are natural processes, but also partly because this is all pretty new. Not necessarily the practices, as we've said, but the measuring of that sequestration. And so nobody really knows, you know, there's a lot modeling, intelligent guessing, some hope, just blind hope, for the sake of carbon sequestration.

Tom Previte 22:23 And we're right to be excited for what regenerative agriculture can offer. But how do we get that to become a realistic and highly optimized tool in our carbon removal toolkit?

Tom Previte 22:37 To think this conversation all started with that question, what is soil?

Emily Swaddle 22:43 And the answer turned out to be, soil is a super important carbon sink that we need to protect, but current methods of feeding the world seem to be doing the opposite. Everything we've learned about regenerative agriculture tells me that it's definitely worth doing. I suppose we also can't ignore that there are challenges. Climate Farmers, the startup platform supporting farmers to go regenerative, is working to hopefully overcome some of these challenges. And Ben offered a really helpful overview of the problems that farmers are facing in this transition.

Ben Flock 23:14 So what we realized when we were interviewing both conventional but also regenerative farmers, was that most of them lack access to knowledge, how to integrate climate friendly practices on their soils, or in their agricultural systems. They often also lack financing, which is promoting those, those sustainable measures on on their land. But they also miss a community where they have the feeling, "Okay, I can see that my neighbor is doing the same. They're also caring for the soil as I do." So this is reassurance that you're not alone in doing what you're trying to do. So this is what Climate Farmers aims to be.

Tom Previte 23:52 Okay, so Climate Farmers aren't actually funding farmers to switch to regenerative agriculture? They're not turning up with a bag of cash at every farm, right?

Emily Swaddle 24:02 No, not quite. The role of Climate Farmers is that of an enabler, so they are empowering farmers and supporting them in making the switch through education and building a community. But the bag of cash thing is quite a good idea.

Tom Previte 24:19 Many farmers around the world are living from harvest to harvest. So the cost of switching must be an issue. And although the changes to regenerative agriculture may seem simple, they aren't going to be free.

Emily Swaddle 24:32 Yeah. And you know, it's not just the upfront costs that need to be considered. The regenerative agriculture movement claims that these practices, as we've said, when they're done right, could increase the farmers yield. But that's not gonna happen immediately. You know, we're talking about systems change. So it's not going to happen overnight. And there may well be a period of a few years when farmers actually see a decrease in yield. You know, that could be catastrophic for farmers who rely entirely on these crops for their livelihood. Current subsidy programs are just not set up to support farmers through this sort of transition, as Ben told us.

Ben Flock 25:09 All the subsidy schemes from the EU are not tailored to the so-called eco -schemes, or more sustainable practices, it's only tailored towards the size of your farm, which is creating a lot of expansion mechanisms, and a lot of optimization, industrialization of farming. And this incentivization is not really in line with creating more sustainable practices, it's actually quite the opposite. The biggest household of the EU goes to the farmers, and a lot of farmers are struggling economically because of systemic pressures and low prices for for projects that they're growing.

Emily Swaddle 25:48 Do you know what, it just seems so counterintuitive to me that there are so many subsidies being thrown at the agricultural sector, but they seem to just maintain the status quo, which as we've learned is very damaging to the soil, and therefore potentially the future of mass food production. It's pumping money into a system that's self destructive.

Tom Previte 26:09 On the flip side, though, Aldyen talked about how the private sector can provide a solution here. She told us, for those looking to make an impact, investing in these transitions may be the best way to spend your money.

Aldyen Donnelly 26:21 Very quickly you discover that when you invest in activities that reduce emissions, and particularly that draw down carbon into the soils and root systems, you are at the same time, you're mitigating climate change risk, you're also building a soil stock that is more resilient in the event of global warming. There are hardly any other investments, there are a few but hardly any other investments you can find that give you both mitigation and adaptation in the same spending pattern. So that ends up being a very cost effective if you do again, pure business analysis, it doesn't make sense to send your dollars other places until you've exploited all the opportunities in that space.

Emily Swaddle 27:02 So we haven't actually mentioned this yet, but as Aldyen said, soil needs to be resilient to climate change as well. Back to financing though, Aldyen claims that this is kind of a win for everyone, right?

Tom Previte 27:13 Yeah. So Aldyen's got really good insights into this space. Essentially, Nori's role is to provide a marketplace to link those that want to pay for carbon sequestration to those that do the sequestration itself, i.e. the farmers. Traditional credits are expensive. But Nori's approach shows that carbon removal credits in regenerative agriculture can both be affordable for the purchaser and beneficial for the farmer.

Aldyen Donnelly 27:38 We're sitting here struggling with how we make the market pay 242 bucks a ton for some strategy over there. The average US farmers, a crop producer in 2020, realized the highest net income per acre that they've realized since 2014. And that was $55 an acre if they can sequester a ton an acre a year and yet paid $40 for that. I mean, have you ever seen anybody look at an opportunity to bump their bottom line bigger than that?

Emily Swaddle 28:10 So, win for soil health...

Tom Previte 28:13 Check.

Emily Swaddle 28:13 Win for the health of the planet...

Tom Previte 28:17 Check. Because we can store more carbon.

Emily Swaddle 28:19 Win for farmers...

Tom Previte 28:21 Check. Because they get both an increase in their yield and they can earn money from sequestering carbon.

Emily Swaddle 28:26 Yeah. And it's a win for food production. So that's a win-win-win-win.

Tom Previte 28:32 And governments are catching on to this. In recent months, there's been talk of updating the CAP, which is the Common Agricultural Policy of the EU. This would include incentivization for farmers to capture and store carbon on their land, and it offers the potential for a whole new business model for farming.

Emily Swaddle 28:49 Yeah, and that's actually where Nori comes in. That's the business that Aldyen co-founded. Nori is a marketplace for carbon removal credits, and it focuses its investments on agriculture. So agriculture credits are actually one of the most affordable carbon removal credits that you can purchase at the minute. It's also growing in popularity amongst companies that are pledging net zero.

Tom Previte 29:12 And this is all wonderful news, as long as it's reliable. Now, we mentioned earlier about the varying numbers. If we face the same uncertainty when trying to measure the carbon that's been stored, there's no way this can be a reliable section of the marketplace. Nori can't sell carbon removal credits if they don't know how much carbon is being stored.

Emily Swaddle 29:31 Yes, and we've talked about this before: measuring the amount of carbon captured is a tricky business, and particularly when dealing with natural solutions and complex ecosystems. Climate Farmers do have this on their radar though.

Ben Flock 29:44 Our goal is definitely to find new ways of monitoring or measuring positive ecosystem services but also the capturing carbon and a lot of research there still needs to be done. At the moment, we have the problem if we want to assess the carbon capture potential, or the changes in carbon stock in agricultural soil, it's very inefficient and costly to go on a piece of 100 hectares, for instance, to do soil tests. And there's a lot of incongruencies in those test results. There's a lot of modeling techniques or frameworks, which estimate carbon stocks in the soil and there are some research says that they're up to 95% accurate. So yeah, there's a lot of potential in this. There is the possibility of also, and a very active open source community also who wants to prove the case for remote sensing. So calibrating satellite imagery with soil samples, and then making the underlying algorithms learn how to assess carbon stock. You could also combine it with drone imagery to have more high resolution imagery. But that's, of course, always dependent on the, on the context. Yeah, so there's a lot of attempts, a lot of promising approaches, and a lot of research going into this.

Emily Swaddle 31:05 I would love for this information to be available to consumers. You know, if this tech can make a reliable measurement of how much carbon my farmer is storing in their soil, I want that to be on the lettuce that I'm buying, you know, put it on the label: this farmer has X amount of carbon stocks in their soil. I'd buy that lettuce.

Tom Previte 31:25 Can we also just appreciate, again, the leveraging of technology and how the farmers are using satellite imagery, combining that with their own data to map whole plots of land? Natural solutions meets modern technology. Very cool.

Emily Swaddle 31:39 Yeah. And it's also reassuring that measurement is being taken so seriously. There's a quote I like by Peter Drucker, a man known as the founder of modern management. He said, "If you can't measure it, you can't change it."

Tom Previte 31:54 That's nice. I like that.

Emily Swaddle 31:56 I think that actually as a quote it kind of applies really well across the carbon removal space.

Tom Previte 32:01 And as well as measuring it purely for the purpose of selling a credit, we need to make sure it stays in there.

Emily Swaddle 32:07 Ah yes, our old friend permanence.

Tom Previte 32:09 We spoke about permanence last time, with regards to maintaining and protecting trees, and the same goes for soil.

Emily Swaddle 32:16 Yeah, I mean, presumably, if these degenerative agricultural practices were to creep back in, or if the land were to be sold and used for something else, the carbon could quite easily be released, right?

Tom Previte 32:28 And that's not the only worry, we have to anticipate for natural changes in climate as well. So the bottom line is, we can't rely on consistency long term. Nori's got a novel answer.

Aldyen Donnelly 32:39 One credit, and we're controversial here, but I feel comfortable that we're right. For us one credit is one ton, incremental ton drawn out of the atmosphere with our guarantee that that recovered carbon will be retained for 10 years. So the seller contracts with us that they will be retained for 10 years. If we discover the carbon's been released, we have an obligation to the buyer, we Nori, to go to the market, buy an NRT and retire it to keep the buyer whole. And then we work out whether or not we have to or might recover those costs from from the supplier. Where we're controversial is you'll see in the wider marketplace, this promise that it's one ton sequestered for 100 years, called permanence. And when we started Nori, we understand, we get the desire to achieve ermanence, I actually get gathered up as many of the the agreements that people had signed that we're all told establishes permanence. I haven't seen every one of them in the world. But I've seen a lot. And not a single one of the agreements I've signed, actually legally establishes carbon retention. They tend to restrict how the land can be used for the next 100 years, but they don't create a revenue stream that protects the carbon stock and the restrictions on land use. So we were sitting there saying, well, we don't want to be yet another market that is promising buyers they're getting permanence when they're not. And then we realized, well, the other thing is, the landowners are providing a carbon warehousing service. You don't expect somebody to, you know, take your furniture into their warehouse and keep it for the next 100 years till you show up again for one payment. So we agree with the goal of permanence, we just disagree with others about how to get there. So we're saying, get used to the idea that one ton times 10 years is our credit. If you're a buyer and you want to buy the equivalent of permanence either set up a fund that's buying a new credit every 10 years or buy 10 right now, but don't expect, because it's unrealistic and you're not anywhere else, I don't care what they say, getting permanence, and you won't get permanence if there aren't continuing or repeating revenue streams so get get over.

Tom Previte 34:52 Aldyen's honesty here is refreshing. She's not pretending that this process permanently stores carbon for centuries, which is what we must do long term. Their kind of unconventional approach focuses on the here and the now that urgent action. Would sequestering gigatons of carbon in soil in the short term buy us more time for other more permanent technologies to develop or better emissions reduction strategies to be implemented?

Emily Swaddle 35:20 Yeah, that's a really good point, Tom. It's like an interesting conundrum in this emerging industry. I also really liked Aldyen's analogy with the furniture warehouse. Because it's true. You know, we're asking a lot of people to manage this land and make sure that it's holding on to that carbon. So you know, just giving one payment every 100 years, I don't know, it seems a little much to me. And Aldyen's explanation feels like a good way of looking at, you know, how we value both the land and those who work with it

Tom Previte 35:52 Agreed. Nori do you have an insurance policy of sorts as well, that's supported by their blockchain technology. And it backs up their commitment to those who are buying credits, so should the carbon be released for whatever reason within their 10 year limit.

Aldyen Donnelly 36:07 So our contract with the supplier says that when you approve the sale of your credit, your NRT, you're committing to make best efforts to retain not release that carbon that's underlying, the underlying value of that credit. There's a force majeure clause, which is if nature undermines you or you have to plow because you had a flood or a drought last year, the carbon might get released but you the landowner don't have a liability, because you made best efforts. But we still have the commitment to the buyer that if they buy one ton, they get one ton. 20% of our whole token pool is in what we call our insurance reserve to back our liability under that commitment. As the market becomes more robust, the market value of the token is a function of the marginal cost of getting the next carbon credit supplied in the carbon market plus the supply of tokens. So by backing our commitment with that token pool reserve, basically, everybody who's buying Nori credits is sharing in the cost of keeping that commitment to everybody.

Tom Previte 37:18 I really liked that approach. I really like that they're not over promising and under delivering That blockchain approach means that even if a natural disaster strikes, you're guaranteed to keep that one ton of carbon you purchased. It's just it'll be somewhere else.

Emily Swaddle 37:34 Yeah, there's natural disasters. You know what they say Tom, and showbusiness never work with kids, animals or natural ecosystems. You never know when the unexpected is going to come along and wipe out all your carbon stocks.

Tom Previte 37:46 Is that what they say?

Emily Swaddle 37:47 I'm sure people say that, yeah.

Tom Previte 37:52 So at the start of this episode, we asked that question, is soil one of the key tools in our carbon removal toolkit? And the answer is yes, but possibly for the shorter term thinking, you know, stemming the flow, affording time for other, more permanent solutions to come through. And we learned that healthy soils do more than just store carbon, right?

Emily Swaddle 38:17 Yeah, I mean, thinking on that point of the shorter term, those stats that we got from Aldyen were really impressive but ultimately, I don't really think we need regenerative agriculture to sequester all of our current emissions. First of all, because we need to reduce our current emissions. Like, we can't just stick at this level and hope that carbon removal is gonna fix everything. It's, that's not how it's gonna work. And secondly, because we don't really want to put all our eggs in one basket here. You know, there are lots of other cool and interesting ways to draw down carbon that we'll go on and chat about in upcoming episodes, we need to kind of be doing bits of everything. Yeah, that just says to me, let's do it anyway, it's got all these other benefits, even if it's only drawing down 5% of current emissions, great. We'll take that 5%

Tom Previte 39:08 The difference in the scale potential there I think very much goes back to the data. And measuring correctly, measuring how much carbon we can put in a particular type of soil and also measuring that permanence.

Emily Swaddle 39:24 Yeah, it's that proof of concept that we need comes from all that data and measurement for sure. Honestly, it feels a bit like we've touched on a, kind of a silent crisis. Like, I don't know about you Tom, but I had no idea that soil was, a) so important, and b) being so degraded. You know, it wasn't something was really on my radar.

Tom Previte 39:44 It was totally wasn't on my radar either. And after doing a bunch of research, I remember walking in a field which had been recently plowed, and just being so upset, seeing, seeing that field left fallow and overturned. And just as we said, At the beginning, you know, this is a very common practice.


The Carbon Removal Show is a Restored.cc and Cofruition production. We are sponsored by Patch. Here's who made this episode happen:

  • Emily Swaddle & Tom Previte - co-hosts
  • Ben Weaver-Hincks - producer
  • Henry Irvine - researcher
  • Sam Floy & Patrick Carter - project managers
  • Mercy Barno - editor
  • Sam Carter - music producer

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