How regen washes methane from the sky

Hello, welcome to Farmgate. I'm Finn Lokastain, the editor of 8.9.com one of the most pressing aspects of ecological and agricultural land use is, in my view, the rehabilitation of the cow. We've been told for so long that cattle are driving global warming, when in fact, and I use that word quite deliberately, cattle in regenerative farm systems that use rotational grazing of one form or another deliver remarkable ecolo value at the same time as producing food and fibre. Now I'm not going to re rehearse the cow's every virtue right now because we're going to spend this program focused on one very particular and little understood process. But I do want to flag up my TedX. We can't solve the climate crisis without cows. If you haven't watched it yet, please do because it sets out the argument for the inclusion of ruminants in agroecological farm systems clearly and accessibly. And it's available on YouTube. Today we're going to focus on methane, specifically how it breaks down in the tr the air around us at ground level. And we're going to talk about hydroxyl radicals, the highly reactive molecules that interact with methane and dismantle it back into its constituent parts of carbon and hydrogen. We're also going to talk about where hydroxyl radicals come from and why in well hydrated regenerative pastures there are more of them, meaning that they can work more rapidly to break down the methane produced by the grazing cattle present in those managed ecosystems. To take us through the science. It is an immense privile to be joined by someone who has followed methane and the functioning of hydroxyl radicals down the rabbit hole for more than a decade. Stephen is known on X as egenitarianism and his blog can be found@lachefs.net now Stephen shuns the spotlight and speaks publicly only extremely rarely, which is why if you're watching the screen is blurred. And Stephen isn't an academic, but he is someone that high level academics turn to for insight on these subjects because his knowledge is so deep and broad, following a great many years of synthesizing knowledge from hundreds of peer reviewed papers that address methane's physical and chemical processes and working to understand them in the context of ruminant agriculture. Stephen also advised Peter Bick during the production of Roots so Deep, the documentary series about adaptive multi paddock grazing. Now welcome Stephen. I want you to start us off with a spoiler, the end point if you like. We're going to get into the details as we move forward. But just start us off with the key message. Regeneratively grazed ruminant farm systems can change atmospheric oxidation capacity, potentially leading to the much more rapid processing and breakdown of biogenic methane. How?

0:05

Well, before I start with that, let me just note that I did write a blog that has a lot of definitions and nomenclature. So it's a reference that people can refer to if, you know, they want to go along with some of what I'm saying. Now, in your intro, the key word is regenerative grazing. There's all sorts of grazing. And regenerative grazing in this context is usually referred to as adaptive paddock management, or ant management, or holistic plant grazing. And it's not a prescriptive system. It moves cattle in such a way that after they bite a plant, it allows that plant to recover. And the key thing is it maintains the root stock below ground. And this is usually in a pasture, a diverse pasture of forbs, legumes and grasses. Now, bad, continuous and prescriptive management doesn't move the cattle. The cattle sit there and bite the same plants, and the plants lose their root stock. The thing with maintaining the root stock is that through photosynthesis, you know, carbon's fixed. And when an animal bites, it redirects carbon in the vascular tissues of the plant from going up to the seeds and leaves down into the roots to get minerals to fix the plant. And those that carbon is exuded from the root tips as carbon metabolites in exchange for those macro micronutrients made available by the soil microbes. Now, when you maintain the rootstock, it also maintains arboruscular mycorrhizal fungi associations. And those that fungi also exudes a protein called glomalin that clumps soil together. So, in other words, better grazing management improves soil health and soil structure, which increases organic matter. And when you do that, that increases the infiltration and retention of water. So when rain falls, more is effectively held.

2:45

Water's really important in this, isn't it?

4:43

Well, we'll get to that. When you have more water and CO2, you have greater above and plant ground biomass and greater below ground fungal biomass. And those plants in turn, they emit three things, oxygen, water vapor, and biogenic volatile organic compounds, also known as BVOCs. Grazing also releases the BVOCs when they bite. That puts the plant under stress and it releases, you know, a bvoc, especially methanol, in grasses and forages. Now, the water Vapor and the BVOCs in turn, are precursors for hydroxyl radicals, which we'll discuss. And especially for the main pathway, which is called the ozone photolysis pathway and other pathways that form hydroxyl radicals, moisture is very important. So once you have more hydroxyl radicals, you increase what's called the aoc or the atmospheric oxidation capacity. And that's the capacity of the lowest part of the atmosphere, the troposphere, to break down hydrocarbons, including methane, back to cyclical CO2 and water.

4:45

So this is about the capacity of the atmosphere to actually do that work, do that laundry process, isn't it? So the, the atmospheric oxidation capacity is about the degree to which the atmosphere is able to break down the carbon. And what you're saying is that these well hydrated, these functioning soil. Soil. The soil in the pastures is helping with this?

6:01

Well, basically, the cattle are the tool to restore soil health. And soil health increases water retention and water retention improves plant growth. So with more plant growth, you have more evapotranspiration of water and you have more release of these BVOCs. And those in turn help form the hydroxyl radicals which break down the methane that's emitted by cattle and a myriad of other things in the ecosystem. One other interesting thing too is that the BVOCs, they actually can react with hydroxyreticals and form what are called secondary organic aerosols, which are tiny particles that seed cloud and cause the water vapor in the clouds to consolidate. So they make rain clouds. So in a way, when you have more plant biomass, it can also lead to more rainfall at the microclimate level.

6:22

And that's something that we found, isn't it, in the Chihuahua Desert, for example, that, you know, where pasture has been recreated through grazing cattle. It's actually created its own rain system.

7:15

Yeah, it creates a little microclimate within the area where they've turned the desert into a grassland. They've increased moisture literally from rainfall.

7:26

And the key here is that the cattle have been used, you know, with regenerative grazing to recreate the pasture. Because just sort of taking the opposite of what you're talking about there, if we're thinking about cattle in a desert system, or even just in a set stocking system where they're sort of eating the grass down to a low level, there isn't that sort of root building going on, then there are fewer of these hydroxyls being created and therefore there is less capacity for the atmosphere to break, break the methane down.

7:35

Well, what can happen when you're not properly. Instead of building soil health, you're degrading soil health. You're leading to compaction. So rather water permeating the system. Water runs off and you have more bare ground, you have dying grass. You can literally see this in the Chihuahua Desert, the ranches that are using regenerative grazing next to the ranches that are still using more conventional practices. There you see, you know, the grasses versus bare dirt and ground. So one's a. There's a big change in the relative humidity of those two juxtaposed methods of grazing. So one leads to a trophic cascade of life and the other leads to a trophic loss of life. So, you know, it really comes down to human management and it's not the cattle itself.

8:03

And I just want to sort of, again, kind of just break this out slightly more, which is, you know, because we're not suggesting, are we, for one moment that it's just pasture that's managed regeneratively that's producing the hydroxyl rad radicals because it's creating and generating that great soil health and that great water absorption capacity, but also other sort of functioning ecosystems. So if you've got pasture that has agroforestry kind of integrated within it and trees and hedges around it, then that really is that kind of perfect world scenario, isn't it, for production of these hydroxyls?

8:51

Yes and no. I mean, because again, I think you have to look at each ecosystem what fits the ecosystem context best. I mean, in some areas, yeah, Silva pasture is ideal solution because you're getting a lot of carbon stored in the biomass of trees. And then you have ectomycorrhizal fungi and arbuscular fungi, and that's another huge carbon pool. And that all creates, you know, a spongy soil that's really absorbent and can retain a lot of water and grow a lot more plant biomass. And it's that moisture and that relative humidity which we can get into later and how that's key to forming hydroxyl radicals, which are what's needed to break down methane and the other gases that are emitted by plants, which is a huge array of hydrocarbons, but all of which have shorter lifespans than methane.

9:24

And I guess what we're really sort of honing in on here is a rebalancing of carbon cycles, isn't it? Because of course, ruminants of one kind or another, you know, huge or small, have existed in the world since pretty much time immemorial. And these things have been in cycle. We have been responsible for breaking that cycle. So through regenerative grazing we're able to rebalance the carbon cycle to an extent, particularly in terms of fixing and enhancing the carbon sinks that are necessary to offset the methane that's being produced by the cattle. Is that right?

10:14

Yeah, I mean, humans are good at screwing up nature's balance, at least modern humans. And when you look at photosynthesis broadly, that's how you're fixing atmospheric carbon. You're fixing CO2, you're putting into glucose, and then via the carbon cycle, it's then transformed into a myriad of other liquid and solid carbon compounds that form plant and animal biomass higher and higher up trophic levels. While this occurs, you're also a lot of carbons being held in solid and liquid pools for varying amount of times, including soil sinks, as well as in the plant and animal biomass. Though a lot of carbon is also constantly being re released into the atmosphere as a myriad of carbon gases from plants, animals and microbial products. These glasses include a wide range of hydrocarbons, including methane, you know, the BVOCs I mentioned, and carbon monoxide. A lot is also emitted, quickly oxidized back to carbon dioxide when all these gases are released from a myriad of different sources, turning methane and other hydrocarbons eventually back into CO2. And water vapor is a part of the carbon cycling that people forget about. So to summarize, the CO2 gas is fixed, transformed in the liquids and solid forms of carbon, which emit other gases and are eventually broken back into CO2 to complete the cycle, to start the cycle over again. And that breaking down of the gases occurs in the troposphere. And so that troposphere, it's kind of, it's not a sink in the sense that we're storing stuff, it's more a sink in that we're transforming stuff. And 90 to 95% of methane oxidation occurs in that troposphoric sink. But it's the same carbon. It's being cycled and recycled and cycled and recycled. And you know, when you read a lot of papers or you hear a lot of people talk about ruminant methane, you think that they're always emitting more and more and more and more methane when it's always the same methane that's being cycled and recycled over and over again.

10:43

We're going to get into all of that, we're going to break that down throughout the rest of the program. Thanks so much for that, Steen. So as we kind of had a 10 minute sort of summary, I guess, and before we go any further and start sort of Going into that in more detail, I think it would be helpful if you could just introduce yourself to people a little bit more. And I wonder if you could just talk a little bit about where your interest in ruminant methane came from and how you've learned and synthesized what you know, that's.

12:48

I'm not sure whether to give the long story or the short story.

13:14

Let's just, just, you know, I've always.

13:19

When I was a little kid, I was really interested in applied chemistry. I was taking college sources as a 15 and 16 year old and did independent research in a university chem lab. So it was a little bit precocious. That research dealt with stabilizing, fluorescing dyes that could be used to optimize photoelectric conversion. Because light is emitted at a certain wavelength at a broad spectrum, and photoelectric conversion works best at a specific wavelength. So with a spectrophotometer, I was making different solutions of ternary compounds to try to stabilizing these dyes that you would in turn apply as thin films on the top of photovoltaic cells to maximize photoelectric conversion. You know, I had to deal, you know, with quenching rates. And I was working in a lab with a grad student who was doing something similar. And I looked at that at that time and I was saying to myself, you know, I was a little bit more grandiose in my personality. And it did kind of like dissuade me. And I went a completely different direction, which ended up ultimately with me being part of a institutional food company from the beginning, where I played my major role in building that company. And we went from like one location and to over 300 locations in 10 years. But, you know, that entailed working four to 500 hours a month. I did that for 11 years and I ultimately just walked away. But while I was at that company, I wasn't in the kitchens. I worked with the operations people and I saw what they were doing and everything, you know, was food costs and unit costs and everything was getting everything, sourcing everything, so it was cheaper so we can get the highest profit margins. And everything came off the back of a US Food or Cisco Truck, which are the large distributors. I think Cisco is global, so you probably have them in the UK as well. But, you know, after 11 years, I kind of walked away from that and I moved to the West Coast. They closed down my firm. I just had enough. But while I was here on the west coast, one of the competitors of that company, I helped open Tracked me down. I worked another four years for them and for another large food institutional food company. They too got their food from large distributors. So again, I walked away. I was a partner in a company. I quit and to kind of network, you know, I was a sole proprietor and I couldn't really work for the big guys. So I tried to network with small operators in la. And to do that, I started a column writing about chefs, thus the title LA Chefs. That was a way just to network. And as I got to know a lot of these celebrity chefs, like, you know, Curtis Stone and Ludo and some of the other people who aren't as famous, I got more interested in, you know, their dishes and where the food was coming from and sourcing. So I started to visit farms and ranches. And one of the ranches I visited was Nicolette Niman up in Marin county back in 2013 14, just before her book came out. You know, I saw what she was doing and it was like, wow, that's pretty amazing. You know, I've been to a number of other ranches since then. So I helped Nicolette with all her social media, setting it up and building it and running content. And I did that all pro bono for free. That in turn led me to a lot of conferences and workshops and a lot visiting a lot more ranches and writing more about the farms and ranches, which also, you know, I met Richard Teague, Jason Roundtree, and I've been in correspondence with them ever since, which in turn, you know, I have a tendency to go down a lot of rabbit holes, and especially when my autistic tendencies kick in, because then I hyper fixate on things that interest me. And with food production, that's a wide array of topics, including climate science, microbial soil science, atmospheric chemistry, range science, botany, nutritional science, etymology, microbial ecology, etc.

13:21

And you've talked about your autistic tendencies being a bit of a superpower in this regard.

17:38

Yeah, because, I mean, I'm like, super honest and if something doesn't work, I'll say, God, that's stupid. It doesn't work, it won't hold on to it. But I'll also, like I said, hyper fixate on things. I've listened to tens of thousands of lectures, webinars, presentations, videos. I didn't just read a hundred hundreds of papers. I read thousands of papers on these topics. You know, methane was always this thing, like enteric methane was, you know, always this thing. You know, how could the. How could we have all these ruminants? And for this system to work so ineffectively. So, you know, a lot of people were kicking around the idea of methanotrophic bacteria. And I looked at that, and I looked into airborne methanotrophic bacteria. And, you know, once the methane's in the atmosphere, you can't just suck it back down. And cattle heads are in the atmosphere. They may move down to graze, but, you know, they're belching it into the atmosphere. It's not being sucked back into the ground. So I'm, like, talking about this to one of my friends and who I consider a mentor as well, Dr. Christine Jones. And she casually mentioned hydroxyl radicals. And I'm like, whoa, that was like 11, 12 years ago. And so then I just started reading, you know, some of the background, like RG Print at mit, who. Who's written a lot about this. You know, like I said, I've just been fixated on it ever since. And it's. It's super complicated. I'm only scratching the surface of the science because hydroxyl radicals interact with a gazillion things in the atmosphere. It all looks like clear air. But the one big advantage with someone like me with. With these autistic tendencies that, as well as a wide array and interests, is that I can see a lot of connections with things when, you know, scientists who, because of the complexity of what they're studying, have to stay within their silos. They can't make those connections as easily, though. One of my things I've always said about the thing is that the difference between. When it comes to making connections is that the difference between a madman and a genius is that the madman makes connections only he can see, while a genius makes connections no one else can see. And unfortunately, I'm probably more of a madman than a genius.

17:42

But that may well be the case, Stephen. But it's certainly very helpful from our perspective. Of course, as you say, you know, the science that we're talking about, there are so many nuances to it. And if you go down, you know, particular elements, you can go down rabbit holes of these elements, elements very deeply, and it becomes very complicated very quickly. And what's fantastic about you is that you are able to make those connections and therefore help to explain things in context and to help us to simplify things for people who don't have umpteen PhDs. So thanks so much for that sort of basic biography that's really interesting. It kind of sets the context for, you know, why I'm talking to you and why it is that you know, many people regard you, I know that you don't like this term yourself, but many people regard you as quite a world authority on this particular issue. And the key focus in this program, of course, as we've been sort of saying, is how methane breaks down and how we can help it to break down more rapidly almost in situ. But we probably ought to start talking about the gas itself. Where does methane come from?

19:59

Methane comes from a myriad of sources in both toxic and anoxic varmints with and without oxygen, including termites, cockroaches, shellfish, blue green algae, saprophytic fungi, wetlands, lakes, garbage dumps, beaver ponds, rice paddies, fires, you know, the list goes on and on. One paper I Read claimed that 40 to 53% of all methane is emitted from aquatic environments. And another paper noted that methane is emitted at a cellular level. So in other words, methane is emitted from many more other places besides ruments, though

20:57

those are all biogenic sort of sources.

21:35

Well now, well, let me go into that a little deeper. Because methane can be split into biogenic, thermogenic and pyrogenic sources. Those are.

21:38

And just explain those terms for me.

21:47

I was going to get into that. And methane can also be split into biogenic and anthropogenic sources. The biogenic sources are from naturally occurring sources like wetlands and wild ruminants. Thermogenic are from fossil fuels, coal burning, coal burning, gas burning oil. Pyrogenic is methane released from fires. So mankind has a role in the anthropogenic sources, though some of these mankind sources may be manipulated biogenic sources. So if a rice paddy is an anthropogenic source, where a wetland is a natural source, if a beaver in North America is a biogenic source, but if mankind puts a beaver in South America where they're not indigenous, then it becomes an anthropogenic source. It's not always clear. Food waste in garbage dumps is clearly a very large source of methane, and that's an anthropogenic one. You know, all the fossil fuels are anthropogenic.

21:49

So essentially, I guess we've got methane that's coming from plants and animals and things like plants and animals and animals. We've got methane that's coming from fire and methane that's coming from fossil fuels.

22:50

Yeah, and I also kind of categorize them as green, black or red methane, where green is from biogenic sources, black is from fossil fuels, and red is from pyrogenic. This is somewhat analogous to classifying water as green, blue or gray water. You know, and many people claim that all methane is the same and has the same global warming potential, irrespective of the source. Though, as we'll kind of get into later. You know, not all methane lasts the average lifespan of methane.

23:00

So take me into that now. Why, why do you say that? Because we're sort of, we're used to the idea, aren't we, that methane has a half life of nine or 10 years. And I mean, it varies depending who you're talking to. But that varies, you're saying.

23:32

Yeah, it does vary. But. Let me just finish the thought. I was saying, when methane is emitted in a context where there's a greater atmospheric oxidation capacity, it breaks down faster. So all methane is emitted with a context, say pyrogenic methane in a fire. It also is emitted with a lot of carbon monoxide, which uses the hydroxyl radicals. So that type of methane emission will actually reduce the atmospheric capacity to oxidize methane because the methane will be out competed for the hydroxyl radicals by the carbon monoxide. So that's why also, you know, if you can use, use ruminants to reduce fires like they're starting to do here in California, you can actually, you know, when you look at it like a life cycle analysis, the ruminants are emitting methane, but they're, they're reducing fires by eating, you know, ladder, ladder surface and fine fuel. And that keeps, reduces the fire intensity, reduces the co emissions, which therefore leaves more hydroxyl radicals for biogenic methane emissions. So it's sort of a balancing act. When you look at methane life, the time frame of methane is expressed one of three ways. There's a half life lifespan and perturbation time. The half life of methane is the time it takes for 50% of the methane to break down in the atmosphere once it's emitted. The lifespan is the average time it takes methane to break down the atmosphere. And the perturbation time is the time it takes for all the lingering effects of methane in the atmosphere to subside. Currently, the half life is approximately seven years. The average lifespan is about nine to 12 years, and the perturbation time is around 13 years. So if you have 100 units of methane that are emitted at one time, 50% of that methane will be gone in six or seven years. But methane also breaks down along an exponential curve. So some methane can break down very quickly within a few minutes, While other methane that escapes into the stratosphere can last as long as 144 years. The average again, is the median point of that exponential curve. Now, if you kind of go to looking at what's happened since the start of the industrial revolution. The half life, average lifespan and prepaidation time have all increased. And that's the half life has gone from like four to seven years. It used to be four years, now it's seven years. The average lifespan has gone from six to nine years and the perturbation time has increased significantly. Now there are three reasons, primary reasons why during industrialization those lifespans and half lives have increased. And it all comes down to burning fossil fuels. The fossil fuels release a lot more methane that hasn't been part of the carbon cycle for 200 plus million years. So there's more methane and the same amount of hydroxyl radicals. But then there's also, when you burn those fossil fuels, a lot of carbon monoxide is released. And those carbon monoxide uses up hydroxyl radicals. And the third thing is that when you burn the fossil fuels, you create a lot of smog. And that smog interferes with the wavelength of light needed for ozone photolysis to create hydroxyl radicals. So you have these three things. More methane, more CO using hydroxyl radicals, and less ability to produce hydroxyl radicals. So therefore more methane is persisting longer because the atmospheric oxidation capacity has been decreased.

23:45

And within that as well. When we're talking about that sort of reduced production of hydroxyls, we're talking about land use change, aren't we? Where there are fewer ecosystems in existence because more of our land is farmed fairly intensively, industrially. Well, there's, there are fewer ecosystems producing hydroxyls because they're well hydrated and good soil health, etc.

27:22

Yeah, that too. I would kind of start the blame more about 10,000 years ago when we started doing till the agriculture, though industrial agriculture has really expedited the process of land degradation. That's the crazy thing right now as we're emitting, putting all of this carbon that was trapped and out of the carbon cycle back into the atmosphere. Over the past 10,000 years, we've been severely degrading the soil sinks, which in turn have weakened the tropospheric sinks. And we've expedited that during the past 200 years. And even more so the past 100 years with deforestation and, and monocropping and industrial agriculture. All those things have undermined soil health, which in turn has led to, you know, a lot more compaction, soil degradation, less resiliency, less water contained in soil. So greater desertification or even where we've had reforestation it's been of monocrops that are under more stress, that release more BOVCs that also compete with methane for hydroxyl radicals. So we've kind of screwed up the balance. At one time we're releasing all this trapped carbon. At the same time we're degrading or diminishing the sinks that are needed to cycle and store carbon. So it's a double whammy.

27:44

Just the last question I wanted to sort of drill into slightly on methane was around different time horizons. So different science papers tend to use different time horizons for assessing methane's warming impact, which I think can be very confusing for the layperson. Why is that?

29:06

Well, some of it is agenda driven. People have white hat biases and they'll use GWP20 versus GWP100 because it better emphasizes their argument. You know, and some may argue that GWP asterisk is being used the same way, but the reality is that gwp, while not perfect, does a much better job than prior metrics because it recognizes that that methane is a flow gas rather than a stock gas.

29:21

When you say GWP, you mean GWP star.

29:50

What did I call it? GWP.

29:52

Okay, people listening will be used to it being called GWP star.

29:55

Yeah, sorry about that. Now I mean, so GWP STAR recognizes that methane breaks down a lot faster than carbon dioxide due to the reactivity of the CH4 molecule compared to the CO2 molecule, which has a double bond and is, is very hard to break. Thus, as you know, as CH4 is being emitted, it's being destroyed and being emitted. So there's a balance reached now where the old GW P 2100, they just convert everything to CO2 equivalents and don't account for that CH4 cycling a lot faster. So I mean, I like GWP is a much better star is a much better metric obviously because it recognizes that. But it, it's, it still has some limitations and oversimplifies the atmospheric chemistry of CH4 degradation because it assumes that a constant breakdown rate of the average rate of methane. In reality, you know, the methane that lifespan is due to two factors and one of those factors is the hydroxyl radical concentration or availability. In a situation or a, or a location or a context where there's greater hydroxyl concentration, you're going to have much faster breakdown. So in a desert you're going to have slow breakdown. In a more moist grassland environment, you'll have faster breakdown. And in a tropical Rainforest, you'll even have faster breakdown.

29:59

I'm really interested in the way that you talk about that. So you know, we're talking about the difference between methane being broken down in the mass of minutes, literally, you know, right up to 144 years. And of course, as you say, whatever the metric, whatever the science paper, it's having to sort of make some trade offs. Let's move on therefore to hydroxyl radicals. What are they? I mean, we've talked about it a little bit, but just go through it again. What are they, where do they come from and what do they do?

31:27

Yeah, I've mentioned them a number of times already without really defining them more broadly. A radical is a very reactive molecule with an unpaired electron. There are a number of different types. So you can have an oxygen radical or a hydrogen radical. Hydroxyl radical is a single oxygen atom and a single hydrogen atom that has a free electron and is super reactive. They have very short last lifespans, less than a second before they react with some gas in the atmosphere. And it can be a lot of different types of gases. So they're known as atmospheres, cleaners or scrubbers because they react with these wide array of emitted gases and help break those gases down. You know, the gases that they interact with include methane, carbon monoxide and both anthropogenic and biogenic volatile organic compounds. And those are the bvocs I mentioned earlier. They also react with a bunch of other things that I don't really study. You know, I mean, I, I see these papers come across in my inbox and you know, I, I mean, like I said, I'm only touching upon, you know, a, a small sliver of the atmospheric chemistry focusing on this one aspect, which is primarily the degradation of methane.

31:54

Just on that, Stephen, you talked about them existing, you know, for a second or less than a second in the atmosphere. So presumably, you know, because methane can exist in the troposphere, it can go way up into the atmosphere. These things are being created at all levels within the atmospher.

33:11

Yeah, there are a number of different processes. Some occur in the soil, some occur up in the troposphere. You know, hydroxyl radical, when you have all these different gases in the atmosphere, the gas, the hydroxyl radical, will react with the most reactive gas in the atmosphere. And reactivity of a gas molecule is determined by what they call a rate constant. So the larger the rate constant, the more reactive and the faster it breaks down. So something like isoprene emitter from trees has a very Large rate constant and usually breaks down within seconds or minutes where hydroxyl radicals has a smaller rate constant. And since it's an inverse equation, it takes a lot longer to break down. So the methane is going to interact with isoprene, then you know, carbon monoxide and some other compounds before it will react with methane. So that's why it's essential to kind of reduce some of these other competitors so there's more available for methane. Now in regards to your question as to how are they formed, the main like 60 to 70% are formed via what's called ozone photolysis. I'm not going to get too into the equations, I've written about this in blog, but Basically ozone is O3. It's zapped by light at a certain wavelength and it's broken down into a oxygen radical, which is atmospheric oxygen. That oxygen, that radical then reacts with water vapor to form hydroxyl radicals. That's the primary pathway. And this happens up in the, you know, you want to create tropospheric ozone. And that ozone is created has other precursors like nitric oxides. And those nitric oxides can be emitted from soil as part of the nitrogen cycle or come from anthropogenic sources. And ozone, you know, stratospheric ozone is looked as a good thing. Tropospheric ozone is typically looked at a bad thing because it's a pollutant and you know, can be not very healthful. But at the same time you need a certain amount of tropospheric ozone for hydroxyl radical formation. So it's not always good or bad. It's kind of context dependent. You know, a little is good, too much is really bad. But you know, it can be formed versus both biogenic and anthropogenic pathways. But that's the main pathway. There are other pathways that produce, you know, 5, 10, 15% depending on the context. And I put these in the blog and I'm going to put references in the blog so people can, you know, go to the papers. But I mean fennin like reactions with hydrogen peroxide photolysis and nitrous oxide photolysis of hydrogen peroxide. There's even a process that occurs at night without any light where the water air interface creates electrical charge on droplets and the droplets split into hydrogen radicals and hydroxyl radical lightning can also cause them. So there's a lot of processes, but the key thing or the common factor with all of these processes is moisture. More water, more moisture equals greater formation of hydroxyl radicals.

33:26

And when you mention fenton reactions, that's a man made process, is it?

36:36

No, there is a fen in reaction that is a man made process, but there's also a naturally occurring one. It's just the oxidation of a metal like ferrous is iron, or it can happen with manganese or some other metals where they lose an electron and the electrons used to break up hydrogen peroxide, which is H2O2. So there, there are. You can actually also make fennin like reactions with hydrogen peroxide to make them synthetically too. So I've read some of those papers, but I haven't focused on it too much because I'm not so much into geoengineering as I am into natural processes. A lot of the geoengineering processes mimic natural processes. And there's a whole big thing right now of using geoengineering also to increase the atmospheric oxidation capacity. But again, I'm not that interested in the geoengineering projects.

36:40

And obviously, you know, in terms of myself and this podcast, we're interested in how we can, you know, work with nature to create these processes and create this sort of cycling more naturally. And of course, water is a key part of the story that you're telling us, isn't it? And so I wonder if you could talk through why. Well, hydrated landscapes are so important in terms of creating that hydroxyl radical abundance and therefore leading to that more rapid methane breakdown.

37:38

Well, all of the methods I just listed of ozone, photolysis, phenol like reactions, etc. They all work better in environments where there's more moisture. When you use grazing to restore a grassland from a desert, you're going to increase the relative humidity, you're going to have dew in the morning, you're going to have more moisture in the soil. And all of that moisture then is conducive to these processes that form hydroxyl radicals. So you'll have the precursors that are emitted from the plants. You have the water, it's emitted from the plants. You have the better soil structure that creates more plants. So that all increases the capacity of these different processes to form more hydroxyl radicals, which in turn breaks down methane not only from the ruminants, but also from saprophytic fungi, from insects. You know, some insects, like cockroaches, have methanogenic archaea in their stomachs as well. So it's. Any anoxic environment has methanogenic archaea. So, you know, all that methane, the hydroxyl radicals breaks down all of this methane.

38:03

Now I know that at the start of the podcast, we spent Those sort of 10 minutes just giving a kind of a quick summary. And I know there's a degree of repetition here, but at the same time, I think it's important to go through this narrative in more detail and, you know, in this sort of structured way. And so I wonder, Steven, if you could talk us through at point this point, how cattle in regenerative and agroecological farm systems increase and improve water function in the landscapes. And of course linked to that, how we can increase the production of hydroxyl radicals.

39:11

Okay, now we're kind of circling back to where we started, so I don't want to be too redundant, but you know, everything in a regenerative system comes down to improving soil health and structure. You know, my friend Gail Fuller says soil is the answer, whatever the question. So when you improve soil health and structure, it increases water infiltration or retention, which in turn, as well as macro micronutrient availability. All of this means more plant growth. And with more plants and plant growth, there's more water vapor transpired and BOV submitted. This increases morning dew and rainfall via the processes I just noted about hydroxyl radical formation. All those require upon that moisture, which increases the amount of hydroxyl radicals form and thus increases the oxidation capacity of that microclimate or ecosystem. So that breaks down more of the methane because you have more hydroxyl radicals.

39:38

And of course within that, if you have more diversity within the sward, multi species pastures, herbal lays, that sort of thing, then you're getting a greater rooting dental depth, a healthier soil going further down, more water holding and therefore more evapotranspiration as well.

40:39

Yeah, I mean the thing with when you have more diversity, you have more diversity of carbon exudates put into the soil. You also have more diversity of root systems that are tap roots and fibrous roots. And they can go down and they're all interconnected by arboscular mycorrhizal fungi, which help exchange water and source phosphorus and source micronutrients deep down into the subsoil. So all of that just leads to a more vibrant, luscious landscape which emits a wider array of these biogenic volatile organic compounds, emits more water vapor. And you know, you also have the nitrogen cycle going in the soil and so you have nitric oxides that are emitted. So it is all the precursors. It's like throwing all the ingredients into a pot to make hydroxyl radicals. Now, as opposed to like a desertified system where you don't have plants emitting water vapor, you don't have plants emitting BVOCs, you don't have an effective nitrogen cycle. So, you know, you can't create or cook up any hydroxyl radicals because you're missing what's needed for that hydroxyl radical formation.

40:54

And of course, what we're talking about here is such an important story, isn't it? It is the cycling of the carbon within these ecosystems where cattle are an essential part of that, where they're producing the optimum conditions in these regenerative systems for the hydroxyls to form that can then do the work that they do breaking down the methane. And this, you know, this carbon sort of breakdown story, this cycling story is something that we just don't hear enough of. You know, we're talking about it now. It's a conversation that started to be had, you know, within regenerative farming circles, but it's not something that the average person knows. And as I mentioned in the intro, much of what we're talking about here seems to almost fly in the face of the prevailing science, the standard narrative that we hear in the media about cattle and methane and you've called that tailpipe science. And so I wonder if you could talk us through why tailpipe science is a problem and how we can fix it, what we can do.

42:08

Well, if you go back to 2006 Livestock Long Shadow report, that report really looked at gross carbon emissions from extensive systems. And you know, and it was a paper that was pushing for intensification, where intensification is a euphemism for factory farming. And you know, consequently the main emphasis was just reducing enteric emissions from the source, the methane burps through feed additives, ruminant microbiome manipulation, improved genetics, and you know, shortening finishing times. So you have shorter lifespans and consequently, if you look at it on a per unit basis, less lifespan. You know, if a cattle emits X amount per day is going to emit less. That's been the kind of prevailing science. And you know, a lot of academia is funded by the industries that want certain outcomes. So, you know, it basically you put a, what's called SF6 tracer or a mask or cattle in a chamber or use green feeds to measure methane as it, as it's burnt. And then you look at all kinds of variables, feed additives, seaweed, how that affects the microbiota to reduce the methanogenesis. And, and that's where like if I get in my feed 98% of the science is it doesn't look at a broader context. You know, I think it, it was driven a little bit by industry, but it's also driven by simplicity. You know, it's reductive, it's easy to look at fewer variables. When you look at what I'm suggesting with looking at it in, in an ecosystem context, you gotta measure a lot more variables. So it's, it's just a lot more complicated and you know, sometimes the easier science is the science that gets done. But you know what's interesting, you know, about, I don't, I don't think it's without value. I think a lot of it has value. You know, if you can look at feed combinations that reduce ciliate protozoa or methanogenic archaea, you know, you can reduce methanogenesis because the protozoa, for example, they reduce the free hydrogen available for Ikea to make methane. But you know, a lot of that can be done within a natural system too. With regenerative systems, you'll find that the plants, because of the microbial diversity, there's greater diversity of the microbes in the plants that make the secondary metabolites. And those secondary metabolites, like tannins and saponins actually also suppress methane, you know, methanogenesis by, you know, reducing the protozoa or the methanogenic archaea. So you can get 10 to 30% reductions in point source from burps just through, you know, mix better forages that are grown in ways that have higher secondary metabolite content. I don't think it's an either or, it's a both. And again, it's just much more difficult to do where you're measuring a lot more parameters and looking at a multivariable equation as opposed to a equation with a single variable or etiology. And some of it, you know, very heterogeneous landscapes. It's also very complicated. I mean, if you even look at, at measuring soil carbon is very difficult to do to heterogeneity. So it's just not easy to do, you know, and it comes down to we can do it, we have the equipment to do it. But you know, in getting the funding to doing it, you know, our society has some screwed up priorities right now. So getting funding for basic science is a lot more harder than for applied to science, you know, and some of this, a large part of the science where they're looking to reduce, you know, the tailpipe emissions, also has patentable products that you can, you know, try to sell. That's a sort of certain built in bias that leads to things that can have applied applications.

43:05

I wonder if we could talk because I think we're sort of, we're coming gradually towards the end of the program, aren't we? But before we get to the point where we want to start trying to summarize these things again, let's talk about the differences between cattle production systems. Now you've just started sort of talking a little bit there about the fact that of all cattle produce methane, but this varies to an extent based on breed and feed regime. We're interested particularly, aren't we, in the warming that arises from the methane emissions, not the fact that the methane emissions are constant. It's the warming that comes as a result of it, which is affected in part by the speed with which that methane is broken down. And it seems to me that what you're saying is that that is directly affected by the ecosystem in which those cattle live. So that would seem to point to having cattle in regenerative systems being much more effective in terms of carbon cycling, in terms of methane breakdown than having cattle in a kind of desert feedlot system.

46:58

Yeah, that's the correct way. But in a well managed system, depending on where you're at, you're looking at a slightly longer lifespan for the regeneratively grazed animal. So you're going to have more methane emitted over a longer time or less methane emitted over a longer time. So there's a little bit of a trade off. But the feedlot finishing or any system where there's continuous grazing in a way that isn't conducive to soil health, you're going to diminish plant growth or you're going to have no plant growth in a feedlot and you're going to have no emissions that will create the hydroxyl radicals to offset any methane that's emitted. I mean, there's a lot that goes into a lca, you know, how the, how the grains are grown. I mean, I know Paige and Jason did a paper looked at the finishing phase, you know, back in 2016. And you know, when you look at account for the synthetic nitrogen and account for soil carbon sequestration, there are a lot of parameters that have to be weighed. And this is not a parameter that's looked at the oxidation capacity in any of this analysis. So I think when you add that to all of the other benefits of, you know, soil carbon sequestration, I mean, it definitely, I think adds up and gives another bonus or benefit. But at the same time, you know, feedlot finishing is done for to have product year round too, because it's hard to finish cattle properly in certain climates at certain locales. There's a rationale to feed lots that people don't recognize. But those can be improved too. You know, you can have them eating the feed they use can be grown in regenerative systems with COVID crops. And you can background the cattle longer on those cover crops and shorten the time they're in the feedlots without giving up too much in daily gains or expanding their lifespans. But that also comes down to having the appropriate breeds of cattle. And I'm not the best person to talk about for breeds of cattle. I have some friends who are.

47:56

Let me ask you this because we sort of started touching on this earlier on on around the idea, you know, of artificial production of hydroxyls. Is there the potential to use artificial production in these indoor systems in, you know, figure?

50:02

I, I don't know. I, I don't know how scalable those artificial systems are. I, I've looked at one or two papers that had, you know, scaling hydroxyl radical production with, you know, phenolic reactions, but it's didn't stick what that paper actually said. So I don't know the answer to that question. I've seen other things where they want to bioengineer methane, traffic bacteria so it can break down more methane faster. And I'm like leery of any bioengineering or geoengineering. I think we need to better understand the processes before we put this stuff out in nature or use it as a substitute for natural processes.

50:17

And I guess that's the key, isn't it, that it may be possible to create a system where hydroxyl radicals are being created to tackle one part of the ecosystem function and ecosystem processes that we're talking about generally with regenerative grazing. But if we're talking about good soil health, then there are so many more good reasons for trying to improve soil health and the role that grazing has within that in terms of managing water, restoring biodiversity, a whole range of different things. And it's very difficult to try and create artificially the benefits of every single element of that when frankly it's so cheap just to use a cow. And so I guess here's the million dollar question that I've been sort of driving towards in regenerative systems. Is it conceivable that the processes unlocked by the grazing cattle are actually removing the methane in real time, that as much methane as being produced by the grazing cattle, cattle is being removed, or even that there's more hydroxyls being produced than is necessary for that methane that's being produced.

50:59

I mean, it's conceivable that the methane the cattle are producing in a regenerative system is breaking down much, much faster than the half lifetimes of most methane or, you know, or even faster. So whether it's occurring at real time, I don't know the answer to that question. But there are, you know, I mean, if you look at it in total, I mean, they're cycling the same carbon over and over again, they're not producing any new carbon. And the faster that cycling occurs, the less carbon methane can accumulate in the atmosphere. When you have the increased atmospheric oxidation capacity and you're also in a well managed system, you're also increasing to a lesser extent the oxidation capacity of the soil through methanotrophic bacteria and other chemicals, chemical processes. I think it, you know, I couldn't say it with certainty because, you know, I don't have a paper and I'm not out in the field testing this, but the enteric methane or cattle burps in such systems probably aren't the methane it's accumulating in the atmosphere. I mean, you could demonstrate this with carbon, you know, isotope signature analysis, you know, getting a library of what the C 13:12 ratio of the cattle methane is, and then tests with a drone or something further up in the atmosphere whether that signature is present. You know, some of that research is done with top down analysis of methane accounting. But I think More broadly, when one accounts for fixed CO2, only a small portion of what a head of cattle consumes is converted to enteric CH4. It's only like 2 to 8%. And a lot of that fixed CO2 gets diverted into various carbon pools with varying lifespans, including above and below ground biomass, trees and fungi and soil carbon pools. So it's conceivable that when you account for all these different portions of the lca, that cattle are reducing the atmospheric loads of gaseous forms of carbon by locking up more carbon in various carbon pools of solid and liquid forms of carbon while not increasing any amounts of atmospheric methane.

52:05

I guess this brings us to, you know, having different strategies to deal with different sorts of methane. So if we're talking about fossil methane, then first of all we need more hydroxyls in the atmosphere in order to be able to tackle the pollution that's coming from that. But really we just need to be cutting right back on the amount of fossil methane that's being produced, we need to cut down on pollution because the pollution is causing that sort of competition, that excessive competition for the hydroxyl radical up in the atmosphere as well. But in terms of enteric methane, it's about strategies to get more cattle into regenerative systems because those cattle are an intrinsic part of creating the ecosystem processes that create more of the hydroxyl radicals that cycle methane within the atmosphere and restore that carbon balance that we've been talking about.

54:12

That's the thing I think most people don't understand when they look, you know, a lot of people think in America, if they drive by a feedlot, they think that's where all the cattle are, and most cattle are on cow calf and stocker operations, or that's where most of the inventory is and only like 15% is in a feedlot at any one time. And, you know, all that cattle can be using better grazing management and being regenerative systems, restoring land and ideally more and more is grass finished in the 100% grass finished. So they're, they're rebuilding ecosystems using these regenerative practices. And I think the term is agarwilding, which Rebecca Hopkins came up with, one of you UK people, and I think that's the appropriate term because, you know, I was having this conversation with my buddy Will Harris at White Oak Pastures, and, and Jason, and when you look at his ranch in Georgia, you know, I asked him, you know, he runs three herds and each herd uses about 30 acres. So at any one time he's found a 90 acres of a 3400, you know, acre ranch. So it's like 1 to 2% of the land. And what uses that land when the animals aren't on there are all the, as Will said, all the critters, you know, and he has all kinds of critters down in Georgia. And so, you know, you're recreating what all these rewilders want, but you're doing it with livestock. And the livestock and the sale of the meat from the livestock helps finance that restoration of that land, that regeneration of that land. And so, yeah, I mean, that's important to understand that, you know, cattle are some of the best tools we have to restore land. And, and, you know, when they're poorly managed and let to go, they can be some of the worst things that can be also put out on the land. So I think it's a, you know, we come down to that proverbial question, you know, that proverbial statement. It's the, it's the how, not the cow, but it's also the appropriateness of where, you know and, and when you manage properly, you can increase the carrying capacity of land where cattle should be and are appropriate for and start helpfully reducing them from places they shouldn't be, like in deforested rainforests where they clearly shouldn't be. Now, going back to a little point you said about focusing methane reduction. Yeah. We should be focusing on reducing the thermogenic sources and pyrogenic sources and some biogenic sources where the biogenic sources are not in environments that are conducive to hydroxyl radical formation. The problem with the thermogenic is that they're also increasing the amount of carbon that you have to cycle. We have a finite amount of carbo, what's essentially a closed system, but we, you know, all that phytoplankton and algae and zooplankton that sunk to the bottom of the ocean 2 million years ago and was buried and became fossil fuels, we're now releasing all of that again. At the same time, we've been destroying or diminishing the sinks that can cycle that carbon. So, you know, we really need to focus on, you know, reducing those emissions. And if you look at satellite data, the heaviest concentrations are from fugitive emissions from natural gas that should be targeted. Another one is landfills, where we put all our organic food waste. You can cover those with methanotrophic bacteria. That's one strategy. Or you can try to remove all the food waste before it goes into those landfills so it doesn't decay and quickly turn back to methane gas in a, in an ox environment. I'm a big fan of black soldier fly feeds because you can feed all those food wastes to the black soldier fly feeds and keep the carbon in a solid form longer and then use those feeds for aquaculture, so you don't need fish meals and also use those feeds for monogastric livestock. So you don't need, you know, as much soy or corn, which, you know, are. What's, you know, the monocropping is super, super destructive.

55:01

I want to sort of round us out now because I think we've gone through the story and we've gone through it, you know, a couple of times in different ways. So I hope that that's pretty clear to people. I'm going to try and wrap this up together a little bit and perhaps, Stephen, just, you know, when I get to the end of this little attempt to summarize what you've been talking about you could fill in the gaps just finally for me. But by increasing agroecological land use, by ensuring good pasture and agroforestry, by focusing on farm system hydration, all of which can be boosted by the presence of regeneratively grazing cattle, we can increase hydroxyl radical production, increase atmospheric oxidation capacity and process the methane that comes from the cows and from other processes more rapidly, helping to rebalance the carbon cycle. Is that about right?

59:14

Yeah, that's a good summary. I don't have much to add. You know, again, it comes down to as counterintuitive as it it may seem when used the right way in the appropriate places, ruminants are one of mankind's best tools to do a lot of this soil, land and atmospheric restoration. This may seem counterintuitive because poorly managed cattle, especially in inappropriate places, have been a big cause of land degradation and deforestation. So like I just mentioned, once again, it's not the cow, it's the how humans are at fault, not the animals. So with better management, we can concentrate ruminants in appropriate places, in much greater densities so that we can reduce or remove them from places they shouldn't be. And in those places they can have this restorative regenerative effect that creates the conditions for hydroxyl radical formation through, you know, increased moisture, which in turn increases the oxidation atmospheric oxidation capacity, which in turn helps to balance and offset any interior commissions.

1:00:05

Fantastic. Well, look, let's finish there. And Stephen, I'd like to thank you so much for sharing your remarkable knowledge and ability to sort of help us through this complex story. And as Stephen mentioned, he has also created a detailed blog which outlines everything that we've discussed in this program. And I think, though if there aren't already, then there will be quite soon peer reviewed sort of paper references within that blog as well. And you can find a link to that article in the show notes. Look, if you've enjoyed listening, please come back and listen to more. Tell your friends like us, review us and share our links. Farmgate is the world's highest ranking food security podcast and we're part of89.com, the land use news channel, which is supported by First Milk Pelican Ag, the nature friendly farming Network, Friars Moor Livestock Health, Agrolo and individual donors. I've been Finn, Locustain Buy. Bye for now.

1:01:09