306 Cows


Mitloehner studies the emissions of methane from cows. There are now food additives that can reduce it up to 50%. Efficiency of meat production is crucial.


  • Frank Mitloehner



methane, animals, livestock, greenhouse gases, soil, reduce, produce, United States, cows, eat, beef, carbon, pasture, dairy, emissions, co2, fed, years, dairy cows, animal


Metta Spencer, Frank Mitloehner


In this conversation, Metta Spencer talks to Professor Frank Mitloehner about the role of ruminant animals in greenhouse gas emissions. Mitloehner explains that cattle contribute significantly to methane emissions, a potent greenhouse gas. He highlights the nuanced nature of methane’s impact while emphasizing the importance of understanding where the carbon in methane originates from as well as how long it is present in the atmosphere. Methane is different than carbon dioxide and nitrous oxide because it is produced and destroyed.

Mitloehner mentions the Global Warming Potential (GWP) which assigns different values to greenhouse gases heat-trapping potential. Methane’s GWP is 28 while nitrous oxide is 265. He stresses that this number does not necessarily capture the unique characteristics of methane which is quickly destroyed in the atmosphere.

There are opportunities for methane reduction such as managing animal manure and converting it into renewable natural gas. This carbon-negative fuel can replace diesel in vehicles, offering an immediate impact by reducing warming. There is also potential to reduce methane emissions from animals with dietary additives that affect enteric emissions or the belched methane from ruminant animals. These additives can reduce methane production by 10 to 50 %.

Mitloehner clarifies that the reduction of livestock is important, but it must be looked at in the big picture of “overall greenhouse gas.” In the United States animal agriculture is responsible for 4 % of the total greenhouse gas emissions and the dairy sector is responsible for 2%.  

Regenerative agriculture improves the soil health and carbon sequestration. Proper grazing practices can enhance soil carbon capture and water retention contributing to climate mitigation. Again, it is important to think of these things regarding the scale of their impact. This is why a multifaceted approach is necessary to address climate change.

Diverse approaches need to be considered. There is potential to improve the rotational grazing methods to make them more efficient. Both feedlot systems and extensive grazing can coexist. It is important to optimize both systems for efficiency and environmental benefits. 

Fossil fuels are the major source of methane emissions, not livestock. Addressing fossil fuel emissions is crucial in the fight to combat climate change.

Many global livestock emissions come from developing countries where the herds are less efficient and the potential for disease is increased.

Enhancing soil health is important for mitigating climate change as well as carbon-negative solutions such as converting biogas into renewable natural gas (RNG). In some cases, additives in livestock can assist in reducing methane emissions. These additives are not widely accessible in developing countries but improving overall livestock management practices are helpful.


The following transcript has been machine-generated using “otter.ai.” Prior to using information from the transcript, please watch the video to catch any obvious errors.

Metta Spencer  00:40

This is Frank Mitloehner, a professor specializing in air quality in the department of air Animal Science at the University of California Davis.  I want to hear more about what you have said — that that we have it all wrong when it comes to recognizing the impact of ruminant animals on the greenhouse gas emissions in the world. Right?

Frank Mitloehner  03:57

Well, it’s a long story. But one thing is for sure – that animal agriculture is a significant contributor to greenhouse gases and particularly a contributor to methane gas. That methane is a potent greenhouse gas. So there is agreement with with respect to methane being a big deal and agriculture being a big deal, but there’s more nuance to it. First, the question of where the carbon that ends up in the methane that comes from cows that they belched out — where that carbon originates and where it ends up. And how long that carbon in the form of methane stays in the atmosphere .All of that needs to be unpacked if you want to understand the beef I have with how livestock is currently being blamed for greenhouse gases.

Metta Spencer  05:53

Okay, let’s unpack.  I’m keen to see what’s in your suitcase there.

Frank Mitloehner  05:58

Okay, so, first of all, greenhouse gases were compared to one another, using a matrix called the GWP 100, the “global warming potential,” which simply assigns a value factor to methane and nitrous oxide, two of the greenhouse gases. Methane’s factor is 28, and nitrous oxide is 265. These global warming potential factors depict the potency of his gases in trapping heat from the sun. That’s not wrong, but it does not accurately reflect the dynamic that methane has, which is very different from other greenhouse gases, the dynamic in causing warming. And here’s why:  CO2 and nitrous oxide, two long lived climate pollutants, once they are emitted – say by our cars or fertilizers applied to fields –  once they’re in the air, they stay there for hundreds or thousands of years. CO2 has a lifespan of 1000 years. When I drive to workin a gas fuelled vehicle, then I produce CO2, put it into the air and it stays there for 1000 years. Every time I’ve ever burned fossil fuels in my life, I’ve produce CO2 and all of that CO2 is still there. The same is true for nitrous oxide, which is a very important long-lived climate pollutants. But the same is not true for methane. Because methane is not just produced, but methane is also destroyed. There’s a chemical process called hydroxyl oxidation which removes methane from the atmosphere. And methane is almost removed at the same amount that it’s generated. But this process that destroys it is currently not considered when using this global warming potential 100 factor. So the other greenhouse gases are just produced, but methane is produced and destroyed almost at equal rate. And that generates a very different dynamic in how methane warms the planet. It is the “Fast and Furious” gas.  Fast and short-lived. While it’s in the atmosphere, it’s potent in trapping the heat. But that offers us opportunities for climate mitigation because, if we manage to reduce methane, then these reductions can have an instantaneous impact on our climate. Even if we were to stop burning fossil fuels today altogether, then all the CO2 that we have produced over the last 1000 plus years would still be in the atmosphere, continually warming our planet. Even if we stop fossil fuel use, we will not reduce warming from that CO2;  it will just plateau. But if we reduce methane, the warming goes down instantaneously. And that really offers opportunities, particularly for the livestock sector. We have found ways of reducing methane from livestock, for example, by managing their manure that traps this gas instead of going into the air. We can trap it, capture it and convert it into fuel. The fuel that we are producing is called “renewable natural gas.” It can replace diesel in our semi trucks, for example. So we can take animal manure, trap the gas that comes from it and convert that gas to fuel vehicles. This is considered the most carbon-negative fuel type there is. It’s incentivized by the State of California very heavily with $200 per ton of CO2 emitted. That is generating real hype right now in the agricultural community. Our dairies have, by the dozens already, covered their lagoons of manure effluent to capture the methane. It’s a multi-million dollar investment per dairy that pays for itself within a few years. As a result of so many dairies having engaged with this new technology, our dairy sector has now reduced its methane by 25%. That massive reduction occurred over the last three years. In addition to the manure management, we can also reduce the methane emissions that come from the animals themselves. What we’re dealing with here is not their farts but what’s called enteric emissions –  the belched methane that comes from the front end of the cow. We can reduce that methane by adding a certain feed additive to the diet of those cows. We can change what happens in their stomach to reduce methane production and thereby reduce enteric methane by between 10 to 50 percent. So, on the livestock side, we are less concerned with CO2 than with  methane. It’s a potent greenhouse gas, but if we reduce it, beautiful things happen. And we are reducing it. And beautiful things do happen. Because when you reduce methane, you pull carbon out of the air, much as if you were to plant trees, which during photosynthesis, also pull carbon out of the air, CO2. The state of California has a goal – to reduce methane from livestock by 40%. We already over halfway there.

Metta Spencer  13:07

That is wonderful. And 95% new to me. What what you said is already provoking a bunch of questions in my mind. This additive – I had heard that a certain seaweed can reduce the fermentation in the animal’s extra stomach and reduce enteric emissions. Is it a component of seaweed that you’re feeding the cows? Or is it something new and different than I don’t know about?

Frank Mitloehner  14:28

Ruminant animals have four stomachs. The largest one is called the rumen and has a volume of 50 gallons, roughly the volume of your bathtub. The reason that rumen is so large is because ruminant animals have the capacity of digesting  cellulose in grass and converting it into meat and milk and so on. Cellulose is a carbohydrate that we can’t digest ourselves. When the microbes digest that cellulose, they produce methane. That’s the unwanted consequence of ruminants being able to digest cellulose. By the way, cellulose is the world’s most abundant biomass  and it can only be digested by ruminant animals. The problem is, when they digest it, then methane is formed as a side product. Now, we have done many studies here at UC Davis, both in my lab and the lab of Professor Ermias about feed additives, including seaweed and essential oils, tannins,. Some of some of those feed additives are naturally occurring. For example, essential oils are made of oregano and garlic, and so on. And some of them are new molecules that are chemically produced in a factory. These different feed additives, by and large disrupt what the microbes do in the rumen. They disrupt the microbes or interrupt the enzymatic steps that they undertake in the formation of methane. We have looked at dozens of different feed additives and have identified 35 or so that were really reducing methane. But of  35 that were advertised as reducing methane, only five actually did so.  But those five did so in a major way, anywhere between 10 to 50%. As I said before this enteric methane is the most important methane source in society. It’s the belching of these ruminant animals that we seek to reduce.

Metta Spencer  17:48

Now I can think of two or three different lines of approach to defending the importance of ruminant animals. Let me enumerate what I think the line of argument might go in all three. Number one would be simply be to say: don’t worry about it, because the methane that the animal is emitting is simply part of a cycle. They emit it but it doesn’t stay there more than 10 years. It gets broken down and it gets turned back to CO2, which the grasses sequester. Then the  cows eat the grass and turn it back into methane, so you’re not adding anything to the total amount of methane in the world. That sounds reasonable, so it’s easy to convert me on that point. Another argument would be to say that the animals actually improve the capacity of the grasses and other plants to capture CO2 by trampling the soil and that sort of thing. I’m sure you’re familiar with the name Allan Savory and his people, who talk about how animals, if managed properly, will improve the quality of the soil, not only by trampling it, but also by leaving their droppings. You want them to leave their poop and urine on the ground, because that enriches the soil and creates greater biodiversity. So that’s argument number two, but it seems somewhat incompatible with what I think you surprised me by by suggesting, which was that you just capture this poop and turn it into fuel. That does seem incompatible with argument number two, because if you’re going to take the poop and convert it to fuel, it’s not going to be out there enriching the soil. You can do one or the other but maybe not both. I have a third, a whole different line of argument, which I haven’t ever seen mentioned in this kind of discussion about cows. It’s a concern about the work of these people called Zimov in Siberia, who are in favor of repopulating the Arctic with huge herds of wild animals, bison. If you could get woolly mammoths, they would be even better. The permafrost is melting, and producing methane from the decaying vegetation that comes back to life when it’s thawed  – emitting methane from these bacteria. Unless something is done to trample the soil and keep it cold, this is going to happen on a massive scale. And in fact, it is happening.  I was certainly persuaded by that argument two or three years ago. It would mean that you;d look back to previous epochs. In the Pleistocene there were far more large ruminant animals on the planet than now. They were emitting large amounts of methane, but it was a fine place anyway. So here we have three different points of view to pursue. So you pick which you want to address.

Frank Mitloehner  22:41

I want to I want to reply to all three. First, the biogenic carbon cycle explains where the carbon in the methane comes from – the methane that’s belched out or that’s coming from animal manure. It originates in the form of atmospheric co2, which is one of the building blocks of plants. During photosynthesis, plants take on that atmospheric CO2 and convert it into carbohydrates that become either cellulose or starch. Then a ruminant comes along and eats the plant material. And then about 1/10 of that carbon in the cellulose or starch is belched out or produced by the animals manure. And now that carbon is changed into the form of methane, CH4. But this atmospheric carbon in the form of methane is not new carbon added to the atmosphere. It’s recycled carbon. It used to be carbon in the form of CO2. That carbon in the form of methane now stays in the atmosphere for approximately one decade – 10 to 12 years – and is then oxidized back into CO2. This is called the “biogenic carbon cycle.” In this cycle, we are not adding new additional carbon to the atmosphere. We are recycling existing carbon. Yes, we are changing it from CO2 to methane, but then back to CO2. While it’s methane, however, it has a considerable warming impact. But because methane is not just produced, but also destroyed, a stable herd of livestock will not add additional methane to the atmosphere. A stable source of methane leads to stable concentrations of methane. And that leads to stable warming. We must be careful not to increase methane because that would increase warming. But if we hold it either stable or even better reduce it, then we can have either a stabilizing or a reducing impact on our climate. And that’s a big deal. So that’s the first point. The second point relates to the dairy side of things where animals are housed in barns and not so much on pasture. The manure that these animals produce is not going onto pasture directly, but it’s flushed into what’s called a lagoon and normally would be stored in the lagoon for months, until it’s eventually applied as fertilizer. Nowadays, farmers cover their lagoons with tarps and capture the gas that normally would be off-gassing from these lagoons. The gas mixture is called “biogas,: they trap that biogas and convert it into renewable natural gas – a fuel type. But that’s just the gas portion of this covered lagoon that’s converted into fuel. The liquid and solid portion of that manure is still available and still contains fertilizer value. So that liquid in the lagoon can still be applied as fertilizer. That’s what happens on commercial dairies where animals are housed in barns. Wherever animals are housed on pasture, you have no control over where manure goes. It’s deposited by the animals, and wherever it lands, it will have an impact on soil. That impact, if applied in the way that grazing animals do. enriches soil. Itt adds nutrients to soil, and particularly nutrients to soil microbes that benefit from that added nutrient. And that increases soil carbon sequestration as a result – the process by which soils take carbon out of the air and store it in the ground. This is really important. That’s the second point. The third one is your narrative around how ruminants have in the past and continue to have an impact on on our climate, on our soils on our air and our water. And that’s very true. If you go to the Midwest of this country here, if you look at the enormous areas of prairie land, then the reason why they have so much fertile topsoil is because of, of millions of years of large ruminant herds grazing on it depositing nutrients that accumulate in there. Now, when Europeans settled the United States in, you know, 200 years or so ago, we have roughly roughly 66 Zero 60 million bison in the United States, and 40 million large Adlabs, so approximately 100 large ruminants in total. When the Europeans came here, they killed off much of that herd of wild, large ruminants, and over time replaced those wild ruminants with domesticated ruminants. Today, we have 90,000,009, zero 90 million beef, and 9 million dairy dairy animals amounting to approximately 100 million large ruminants again, so over the last 250 plus years, the number of large ruminants in the United States have not changed markedly. And that means the amount of methane produced by large humans has also not changed in a major way. What has changed is our addiction to fossil fuel, which has added enormous amounts of carbon to the atmosphere, not just from co2, but also from methane. That has changed drastically. Now the last point with respect to the Arctic, I’m skeptical that the introduction of large ruminants and their whole faction by trampling down the soils will have any major impact in suppressing methane that comes off thawing soils, the soils are thawing. That’s a big problem. But that is not a that is not something that we can in a major way suppress or mitigate. by reintroducing large ruminant herds that would not do the trick. The trick is that would curb our addiction to fossil fuel, which are responsible for at least 80% of greenhouse gas emissions emitted by humankind and try to try to get ourselves out of this this changing climate scenario that’s that’s what we have to do a few ruminants up in the Arctic will not change that.

Metta Spencer  29:43

Okay, but but capturing or reducing the emission of methane from cows would it would they how much of an impact would that have? Suppose all dairy cows in the United States or in North America or wherever Oh, were to be fed this, these additives, and suppress up to 50% of their emissions. And we didn’t change the number of cows or how much milk we use. How much difference would that make in the total amount? We have long, we have a lot to accomplish in the next 1015 years. How much of it can be done that way? Yeah, this is

Frank Mitloehner  30:27

the frustrating part. There is so much reporting on this topic of beef and dairy emissions that people think that they are making up the lion’s share of climate related gases, so called greenhouse gases. But according to the environmental protection agency in the United States, which is the official agency, running the inventories for all sectors of society, according to the EPA, all of animal agriculture combined, that’s beef and dairy pigs and poultry feed production, everything combined, makes up 4% of total greenhouse gases in the United States. 4%. The dairy sector alone in the United States is responsible for a total of 2% of all greenhouse gases. So let’s say let’s say we were very effective in reducing enteric methane and methane from the entire dairy sector, and reduce total emissions by let’s say, half, then that at the very most would reduce us greenhouse gas emissions by a little less than 1%. So it’s definitely not a breakthrough. But every sector has to do their part. And that includes the dairy and the beef sector and so on. But don’t get your hopes up that this will have a dramatic, dramatic change of greenhouse gases. As a result, the lion’s share of us sectors contributing to greenhouse gases are those that are related to the use of fossil fuel, and that’s transportation, power production and use and the use of cement to form concrete, these three sectors combined make up 80%, eight zero of all greenhouse gases.

Metta Spencer  32:10

Okay. Well, now, there are two different approaches, again, I’m reading your your emphasis on dairy cows, as the as a hint about which you’re going to focus on. And that is, you know, you don’t you haven’t talked about this holistic management approach. Now, there are for example, I believe that there is one farm in the US so somebody’s gone quite oaks in Georgia where they have, they claim and I guess, with some measurement, that they not only this is an outfit that uses the system of moving cattle from or their cows from one pasture to another, in a very careful way, very clearly managed way, so as to maximize the beneficial impact of their of their presence, both in stirring up the soil, just the right amount and leaving the right amount of residue there. And they move them carefully. And then they’re careful about the how they managed the the packing of the meat and so on. So they they claim that not only Well, let me back up a little and say that I have read that cows that are kept in feedlots and fed fed grain as that what they call finishing of before slaughter, or I presume that would also apply to dairy cows kept in confined spaces, that those animals actually emit less greenhouse gas, then pasture fed cattle grass fed cattle, but nevertheless, this white oaks place does use the grass fed method. And they claim that the amount that they sequester in the soil, the amount of carbon they actually managed to sequester, because of allowing the cows to live there properly, is greater than the amount that would be sequestered or captured by a reduced rather, I guess, I want to say the amounts of emission reduction that would occur if if they kept them in a, in a confined space. Now, so this is one of the few pieces of evidence that I’ve come across as to whether or not there’s clear proof that the this hurting method of moving large herds of animals from one spot to another has any significant payoff, but what what Allan Savory claims is if you look at a map of the world, the land is Desert defying all kinds of places, it’s turning barren and dry when it’s much more than it used to be. And that, you know, large parts of the world are. The land is used by herders with their own, you know, their own cattle, and so on. So if you ate he would maintain, I think that it while you’re saying you can only handle about 2% of what we need to do, I would think he would claim that if everybody adopted better methods of hurting animals, that they the impact on the soil and the amount of carbon that we could sequester would be a lot more than 2%. I don’t know what its estimate would be. But But that, you know, I’ve seen pictures of the world land that’s turning into desert or dried up, you know, land. So I kind of pin a lot of hope on that now. Is that reasonable or not?

Frank Mitloehner  36:04

Yeah, we’re talking about some different scales here. So we first talked about the dairy industry here, the United States, and their contribution is around 2% of greenhouse gases of the total. savory and others made the remarks based on total on global totals. Okay. And so here, globally, all livestock combined amounts to approximately 14 one, four 14% of greenhouse gas emissions. Okay, so the United States has about the lowest greenhouse gas intensities around the world. But now we are talking global Okay, so, in African countries, also, emissions per animal are vastly larger than they are in the United States, because the animals are much less efficient in how, how much they produce, and when they when they go to the market when they when they get harvested or slaughtered. But let’s rewind a little bit. So you’re you’re referring to a principle called regenerative agriculture and regenerative agriculture focuses heavily on soil health. And I think it’s very important that we do that. I think that improving the soil is one of the most important actions that humanity can take in fighting climate change and also managing the water, because properly managed soils will have much higher carbon capture rates on the one hand, but also much better water holding capacity than soils that are not properly managed. So a proper grazing system can really drastically increase soil carbon capture, and help carbon that’s in the air being captured by plants and then stored in the ground. That does not continue endlessly, there is a an optimum rate and after a while it plateaus. But as long as you keep soil under grazing conditions, and you keep that soil undisturbed. The ground where it doesn’t stay in the ground is when we do what’s called tillage. When we plow the op in when we plow the field, anything that plants have previously assimilated and sequestered, will be released, will be released. When we tell when we plow so savory and others, and I’m not in his camp, but I’m just telling you, that’s what they say. What they say is by by taking land that’s currently simply dirt and not really soil with rich microbial activity. That by turning this dirt into proper soil, we can improve soil carbon sequestration, drastically reduce or drastically increase soil carbon capture and improve water holding capacity. I agree with that. I agree with that. But I don’t agree with the total amount he’s talking about. And you mentioned one thing before, which was also interesting, and that is that intensive farms, such as commercial dairies and feedlots, on a per car basis actually emit less greenhouse gases. And your listeners might wonder, how’s that possible that an animal in a feedlot that seems to be that seems to be cramped with others, because everybody has seen those images that an animal like that would produce less greenhouse gases than an animal that’s on pasture? How is that possible? Well, it is counterintuitive, but it is it is possible and actually it is happening because what generates the methane in the animal in the ruminant animal. Methane forming microbes, bacteria and protozoa. Okay? They’re they’re residing in the rumen of these animals and what are their stomachs and what they need what these methane forming microbes need to grow is roughage. Another word for roughage is fiber. And the diet richest in roughage are forages that animals graze on a diet that is the lowest and roughage is a feedlot diet. A feedlot diet is 80 or 90%, corn or distillers grains or soy which is referred V and only 10 or 20% roughage when you go to a feedlot, you will see very little belching. And there’s very little methane coming out of feedlot animals because their diets, what they eat, in other words, does not lend itself to produce enteric methane. The microbes cannot deal with that diet and do not form a lot of methane. That’s one of the issues. The other issue is that a con finished animal an animal that spends the last four months of its of its life in a feedlot, and the rest of its life prior on pasture, that animal will finish will reach the finishing weight almost twice as fast as an animal that’s finished on pasture. And when an animal finishes almost twice as fast, and that means this animal will have eaten less throughout its lifetime, had less water, needed less land, bounced less methane and so forth. So the lifetime emissions are lower. And even if you consider the impacts of the feed that it’s regrown for the feedlots that also generates emissions. Even if you take the entire lifecycle of the one system versus the other system into consideration, you will find that what people intuitively think is the greener system that doesn’t hold true. So we have to be careful. This is not fingerpointing one better than the other. This is making the whole thing work, pasture and feedlot making the whole thing work.

Metta Spencer  42:16

Okay, well, the people that I am exposed to maybe more than to what you’re describing the biodiversity target people who really want to go back to date and more natural or older methods. And especially for example, there’s a fantasy of repopulating large areas of North America with deep grasses, perennial grasses that grow much farther down into the soil, and can sequester much more carbon and that these are supported by bison and other big animals and so on. So the, the, you know, we have this image of large areas of America being turned into, you know, the way it was before the people from Europe arrived. And now that’s quite different from the approach that you’re taking, which basically says we have a dairy industry. And what you have to do is learn to tweak it in such a way as to make it better, and that that there’s a lot of payoff in doing that right. By by additives. And and by capturing the the effluent from the lagoons and, and so on. So those are two different approaches, right? Is it a choice? Do we have to choose between a romantic fantasy of medieval Americans on the prairies or feed like cattle?

Frank Mitloehner  44:00

Well, it’s not it’s not a choice of this or that is actually doing both. And we are currently doing both. In the United States, we today have 750,000 ranches. 750,000 ranches. On average, a ranch has 50 mama cows in the United States today. 55 Zero. So that is the base of the beef industry in the United States. 750,000 Beef ranches on average with 50 mama cows. Now these animals all these beef animals stay on pasture for approximately a year little little less than a year first with them with their mother and then by themselves but on pasture. So regardless of how a beef animal is finished, they all spent the vast majority of their lives on pasture. Similarly to what your romantic view there entails. Okay? And these these pastures are ranch operations and there are, they’re very similar to what happened prior to Europeans coming into the prairie lands. These are, these are largely grasslands, they might be improved with respect to better forages than what would naturally grow more productive or just, but these are grasslands.

Metta Spencer  45:20

So exactly, excuse me for interrupting. But I think that, that people who do this holistic management would not be happy with what you’ve described, these are large pieces of land and the animals roam freely, they’re not that many, they’re not very dense, they roam freely over it. Whereas the important thing that these peoples claim that is, is to improve the quality of the soil, you have to actually hurt these animals in a very specific way, and expose them for a specific period of time to a certain plot of land. Otherwise, what they’re doing is they don’t have any use for what’s happening now either. You got

Frank Mitloehner  46:02

a question about management, but not the land use of the majority of agricultural land in the United States, where two thirds of all land is grazing right now, two thirds of all agricultural land is in grazing in the United States. So the question is, can that be improved? And the answer is absolutely, we can have improved rotational grazing, which exerts more grazing pressure by herds of cattle, or sheep or goats are so and then rotate them around so we can do better. But the question that you posed was, is it feedlots and intensive dairies? Or is it extensive, extensively raised livestock? And the answer to that I gave to that was not, it’s not a one or the other. It’s both. In fact, if we were to forego if we were to forego the use of intensive areas, and also feedlots, then that would have to be replaced by more grazing with these kinds of livestock species, and that would be more or less intensive. So in my opinion, it is not a question of one or the other, it’s a question of, how do we make both systems work best? Okay, I’m not at all dogmatic about saying, because we have a gold standard there. And that might be regenerative grazing, we now have to convert 100% of US agriculture into that into that scenario, because it won’t work. It won’t work. Because there are numerous considerations, one of which, of course, is the economics that make or break, something like that. I mean, it’s easy for me to sit here at UC Davis and say, I’m sitting in the ivory tower, and coming up with some gold standard that everybody should aspire to. But if I then go into the real world and talk to a real ranchers and real farmers, about what limits them and what deters them from making such moves, then I have to acknowledge, okay, I can’t just shove it down their throats and say, No, everybody do that. I have to I have to root my work in reality, and in what consumers want. Producers can do the consumers, for example, by and large, when given the choice, prefer corn finished beef, not grass finished beef. You have them exposed in taste panels to different beef choices. And I have had I have partaken in those tastes panels, even with top chefs. And, and what they said was, I prefer the one over the other. And it was not what people think that they chose, but it was counter what people think that they preferred the conference over the grass finished. And the reason for that is that the quad finished animals are half the age when they go to slaughter. Because they finished so much, so much sooner. And because this corn fed the last four months of their lives has a profound impact on the taste of the fat, the intramuscular fat that runs that is the marbling of the meat that runs through that meat. So so we have to consider the reality of what consumers demand and what signals that sends to producers. Okay,

Metta Spencer  49:27

okay, you’re dealing with beef and milk producing cows. So what how many you know, I don’t even know what the ratio is. For every beef producing cow. What how many milk producing dairy cows are there?



Frank Mitloehner  50:01

Interesting. So just told me we have no military cars. Guess how many horses we have in the United States, just a wild guess.

Metta Spencer  50:10

You are either was about 30 seconds when you were not audible. I’m sorry. It was technological. So that backup, we left off where I asked you how many for one cow? How many dairy cows are there?

Frank Mitloehner  50:24

So we have it’s roughly 10 to one 90 million beef cattle and 9 million dairy cattle.

Metta Spencer  50:35

You’re kidding, I would have found that. I would have thought it’d be the other direction.

Frank Mitloehner  50:39

No, no, no, we have 99, zero 90 million beef cattle and around 9 million dairy cows and 9.5 million horses, with more horses in the United States than we have dairy cows.

Metta Spencer  50:51

No kidding. Yeah. And those are just for fun.

Frank Mitloehner  50:56

Yeah, they’re just for fun. And we also have 170 170 170 million dogs and cats. But of course, nobody talks about those.

Metta Spencer  51:06

Well, but they don’t produce methane.

Frank Mitloehner  51:09

Well, don’t fool yourself. They are eating a diet that is very similar to a human diet with respect to nutritional quality. And they’re consuming 1/3 of all of our livestock products, to dogs and pets, but we have consumed about 1/3 of all livestock related products. And they are producing a large amount of manure.

Metta Spencer  51:38

Well, the manure produces nothing.

Frank Mitloehner  51:40

Yeah, of course. Absolutely. Yeah. That is not different from what, what? What livestock produces or what humans produce? I mean, it’s all it’s the same. It’s very similar.

Metta Spencer  51:54

Yeah. Okay. All right. That that is a very sad thing to hear. Because I’m sorry. Yes, I love my dog. And I would like to have another one, but I don’t. Okay. So we should give up our pets. Oh, dear. Oh, no, I’m not saying that. Well, we can teach them to eat porn or something. I don’t think that’s possible. They really don’t need meat diet. Dogs and cats

Frank Mitloehner  52:20

are carnivores. Okay. Dogs and cats are carnivores, they need they need that. Okay.

Metta Spencer  52:27

Okay. Now, if you’re thinking in terms of how to save the world, there’s a lot that we have to make some big changes. And I, you know, the question is how quickly we can do what we have to prioritize the most the best payoff in terms of of methane emissions, so that we do the most, most valuable, productive changes as fast as possible. How would you prioritize this? For one thing, we haven’t talked about other sources of methane, such as rice production. And I wonder, you know, what are you what are people in Asia going to do when they realized they should stop eating rice? You can talk about that first. And then let’s talk about priorities.

Frank Mitloehner  53:18

So first of all, the most important emitter of methane is the use of fossil fuels, oil, coal and gas. Whenever we get this out of the ground, a lot of methane comes out to and there are many methane leaks in our pipeline system, and so that generates a lot of methane. And in fact, the increasing amount of methane that we have been measured since 2006, is largely a result of our so called shale gas use, which started really the fracking and so on that started in 2006. Since that time, we saw methane going up. Prior to that our livestock herds have gone down pretty drastically over the last few decades. So for example, in 1950, we had 25 million dairy cows. Today we have 9 million. We went from 25 to 9 million, but we are now producing 60% Six zero more milk with this much smaller carbon footprint of a glass of milk in the United States has shrunk by two thirds of the beef side, we used to have 140 million beef cattle. Now we have 90 million so much fewer, we are producing the same amount of beef. So these improvements in production will continue. Okay, they are not at the end yet. They will continue. We are now today producing 18 one eight 18% of global beef with 6% of the global beef herd here in the United States. So these efficiencies in production, they have everything to do with emissions. And that’s really important. Now you asked for other sources of methane, right? As another source, swamps are another source. But fossil fuel use by far is the most important one.

Metta Spencer  55:08

Everybody’s conscious of fossil fuel with us. Not many people are conscious of, for example, protecting wetlands. And therefore example I’m very ambivalent, because I can see why you want to protect wetlands for preserving peat and not having it dry up and burn and things like that. But at the same time, that is the source of a lot of methane. So tell me what you what, you know, what should be done with with swamps and wetlands, what should be done about especially rice production?

Frank Mitloehner  55:41

That I cannot tell you, that’s not my subject matter area. I don’t know enough to make a useful comment. But I can tell you these are significant sources and people who are specialized in that in that area they need to, they need to wrap their minds around it. I’m specialized in livestock. And what I can tell you is that livestock plays a role in what we eat as matter. But it is oftentimes used as a smokescreen as well. Because there are people who say, all we need to do is change what we eat, for example, become vegetarians or vegans, and all will be good. Well, a recent study went to the extreme and looked into what would happen if I an omnivore were to switch to become a vegan and eat normal animal source foods. The result was that my carbon footprint would would shrink by 0.8 tons of greenhouse gases per year. So less than one tonne. Now is that a lot or not? Two weeks ago, I flew to Europe and per passenger, that flight to Europe generated 1.6 times. So going vegan for one year saves 0.8 times. But flying to Europe per passenger per one passenger generates 1.6 times. So it takes me two years of being a vegan to offset one fly to Europe. Now, if the entire United States were to go Meatless Monday, Meatless Monday, three or 30 million Americans, we would reduce the carbon footprint of the United States by 0.3%. If the entire country were to go vegan altogether, no more animal source foods, we would we would reduce the carbon footprint of the nation by 2.6%. Now you have to decide whether that’s a lot or not. But these are the real numbers. Okay, so I want people who think that their food choices are really important with respect to fighting climate change, to know what the true contributions of that would be. And if you and you did ask me, what what is the 800 pound gorilla? What is the elephant in the room? There is absolutely no question that eight zero 80% of all greenhouse gases are fossil fuel related. Again, that does not mean we can relax towards the other things. But it means we have to have a crystal clear focus on ending our reliance on fossil fuels. And we have to do it quickly.

Metta Spencer  58:17

Absolutely. And fortunately, I think most people are aware of that. Or maybe not. I mean, you got all these deniers but you know, if you ask people what has to be done, everybody will say fossil fuels. And let’s focus on that which by all means, but then I think there’s there’s more than has to be done. I think, for example, negative emissions have to be considered agriculture and so on. So I don’t know how much can be done in terms of sequestering carbon by changing agricultural technology, but it’s not something I wouldn’t overlook. Yeah,

Frank Mitloehner  59:02

I think a lot can be done. I think a lot can be done. The soils I already said are our most important ally. Okay, a third of all human cost, carbon is stored in our soils. That’s hugely important. Lowering of emissions is another main avenue that we have to pursue, okay. And that includes, of course, animal agriculture, along with all the other sources, but a conversion for example of biogas to r&g for renewable natural gas for this fuel type I talked about earlier, is considered the most carbon negative fuel type there is and carbon negative means we are now reducing net reducing carbon emissions, we are pulling carbon out of the atmosphere and that we must do and we must do it at large scale and we are doing it at a large scale. We are doing that at large scale. Yes, because we are leading the way we always have in the United States leading the way that the others are watching us right now wondering if that were to catch on, and I think it will catch on. Because this is also not just environmentally advantageous, it’s highly financially advantageous at all as well, because there is the so called cap and trade system that financially incentivizes the conversion of biogas into fuel. And you will receive credits for it called the low carbon fuel standard credits, and they are very financially lucrative. This conversion of biogas to fuel is the new gold rush in California, right there.

Metta Spencer  1:00:39

Wow. Okay, that is a big excitement to me to hear. But you know, let’s go back in to what is probably a sideline, but this thing about the additives to feed? Because I’m thinking okay, you can you can mix up some goo and give it to your cows. But what about the guys in Africa, and so on? There’s, you know, much of the world’s cattle is not anywhere near California or your your innovations? How widespread is you? Can you visualize the production of whatever these goo things are that you are feeding them? Where do you get it? What’s it made from? Could it be made in other countries? Could it be and could local herders in Kenya, the thought to carry some along and give it to their animals? As long as

Frank Mitloehner  1:01:42

you know, very important question, they’re very important question. The answer is most of the feed additives are not available in developing countries, and will likely not be available in developing countries now, but that’s not in itself a reason to despair, because there are other things that can be done there. First of all, in the governmental Panel for Climate Change, world’s leading body for climate has looked into the livestock sector and the livestock sector globally. And they have found out that approximately 77, zero 70% of all global livestock emissions, and that’s enteric emissions and Minoo emissions stem from developing countries seven to seven zero. Now, you might ask, Well, how is that possible? What Why is that I always thought of feedlots and so on producing a lot of emissions. Well, the reason why that’s possible is because in developed countries like the Americas, or Europe or so, we have shrank our livestock herds drastically over the last few decades. And we’ve become extremely efficient in how we produce livestock and livestock products. That’s in sharp contrast to many developing countries. For example, I just told you before that we have 9 million dairy cows in the United States nine. In India, they have 300 million dairy cows and buffalo 300. They could produce the same amount of milk as they do today, with 1/10 of their cause.

Metta Spencer  1:03:22

If they’re going to make that happen, my goodness.

Frank Mitloehner  1:03:25

So one thing is that they don’t know how to prevent or treat diseases. The animals are full of endo parasites that eat nutrients that we really want to go into the cow. Instead, they are eaten by the parasites, animals get sick, if they get sick, they die. There is no feed and feeding system that’s established, the animals walk around between the houses and eat the blades of great grass that they find. There is no improved genetics for animals and plants. None of that exists in the in a country like India or in most African countries. And as a result, they need to have that many animals to produce the amount of animal source foods that people demand. A country like China, we have been well over 20 times is certainly not a developing country. It’s an emerging country in the rural areas particularly. But before African swine fever hit China, this pandemic that they have been grappling with. Before this disease hit the Chinese. The Chinese produced approximately half of the world’s pigs, 1 billion pigs per year. But off the 1 billion pigs they produce 400 million. So 40% never made it to market because they died pre weaning because of a lack of veterinary care, lack of nutrition and so on. These developments are terrible and they are rampant. Excuse me, not just in China, not just in India, but particularly, particularly in Africa, where people, families or tribes don’t keep livestock in order to raise them and then eat them as soon as possible. But they raise them and keep them because they are their social security and their retirement system. Okay, a group of cattle to a tribe in Africa will live however long these animals can possibly live maybe 20 years. And once these animals fall over of old age, then they eat because that cow is the 401 K of that tribe. Okay. But the problem is, if you have a cow that lives 20 years, live 20 years, then the lifetime emissions are enormous. That same animal could be slaughtered after two years, and then feed people. But instead, it lives 20 years in many of these countries, that gives many of these countries and their livestock population, a huge, huge environmental impact. Or it causes a huge environmental impact, one that we could easily reduce easily reduce next year, if countries like ours were to assist countries like those in Africa or South America or many Asian countries to become more efficient. So they are not at a point where they need food additives, they’re at a point where they need to learn to keep animals healthy, to keep them fed correctly, to house them in a way that minimizes stress and so forth.

Metta Spencer  1:06:39

This is absolutely fascinating. And we have to end now we’re a little over time, but that is everything I’d hoped for. Because now I come away with a whole new set of things to worry about and and to and to celebrate because obviously you’re making wonderful progress. And okay, thank you so much and I certainly wish you Godspeed in what you’re doing. Because it’s it’s you know, can’t there’s nothing more important than what you’re doing, I think less. Thank you very much.

Frank Mitloehner  1:07:11

Thank you very much for having me and Alma.

Metta Spencer  1:07:15

I’ve enjoyed it so much. Bye



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I hope a lot of vegans watch this talk show. The value of meat is that it is a more dense combination of nutrients than can be obtained from a purely plant-based diet.

I was hoping that the kind of meat grown in vats would be sustainable, but lately I saw something showing that it is just as bad for the climate and the meat that grows on hooves.

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