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Dr. Frank Mitloehner - Livestock's Environmental Impact: Misinformation about greenhouse gases

July 27, 2020

Since 1950, the United States has reduced its dairy cows from 25 million to 9 million, but is now producing 60% more milk.

As more and more companies promote anti-meat products, many consumers have been left with misconceptions about the relationship between livestock and climate change. Dr. Frank Mitloehner, professor in the department of animal science at the University of California, Davis, joins us to discuss the myths about livestock’s impact on the environment and why agriculture is not to blame for climate change, but how it is key for a more sustainable future.

The following is an edited transcript of the Ag Future podcast episode with Dr. Frank Mitloehner hosted by Tom Martin. Click below to hear the full audio.


Tom:                          Welcome to Ag Future, presented by Alltech. Join us as we explore the challenges and opportunities facing the global food supply chain and speak with experts working to support a Planet of PlentyTM.


                                    As the scale and impacts of climate change become increasingly alarming, meat is a popular target for action. Many climate activists urge the public to eat less meat to save the environment, and some have called for taxing meat to reduce consumption. Their key claim is that, globally, meat production generates more greenhouse gases than the entire transportation sector. However, this claim is demonstrably wrong, and its persistence has misled people about the links between meat and climate change. These words begin an article by Dr. Frank Mitloehner, a professor in the department of animal science at the University of California, Davis. Dr. Mitloehner specializes in the measurement and mitigation of airborne pollutants from livestock production, including greenhouse gases, such as the methane produced by cattle. Thanks for joining us, Dr. Mitloehner.


Dr. Mitloehner:         Well, thanks for having me.


Tom:                          So, we’ve turned to you to talk about confusion among consumers about the climate impact of the methane produced by cattle. And much of the confusion is due to marketing strategies and tactics by corporations such as Burger King, touting that it's adding lemongrass to cows’ diets to try to cut down on methane emissions, or Starbucks’ decision to stop using dairy products. And I like to begin by asking you to tell us about messaging that has resulted in these misperceptions about the relationship between livestock and climate change.


Dr. Mitloehner:         Well, a lot of this originated in a 2006 publication by the Food and Agriculture Organization (FAO), and they made the claim that livestock produces more greenhouse gases than transportation. And that is very unfortunate because when such an authority makes such a claim, then it has a lot of credibility. However, I proved to that this assertion was wrong and that they used different methodologies when they looked at the impact of livestock on climate versus those of transportation. And they actually corrected that and said, “Whoops, yeah, we were wrong, and we have gone back to the drawing board, and we now use the same methodology when comparing things.” But the horse had left the barn, and all those critics of animal agriculture glued on to this and gloomed on to this, and damage has been done. And so, now, many corporations are using the climate impact angle to either promote their own products or disparage the use of animal-source foods.


Tom:                          Advertising and marketing can be very pervasive and very persuasive. How have these messages been damaging for agriculture?


Dr. Mitloehner:         Well, when you repeat falsehoods over and over again, then, after a while, it becomes truth, at least in the eyes of many of the consumers, and that’s really unfortunate. And one of the reasons, one of the ingredients in this disaster is that agriculture has responded too late or, if so, with some PR (public relations) campaigns as opposed to a real educational effort in infusing truth into this discussion, because it is just propaganda and nothing more than that.


Tom:                          Let’s back up just a bit and talk to that consumer, who most likely has heard that cows produce methane, that methane is a significant greenhouse gas, and that beef production contributes to global warming and climate change. And first, if we could ask you, Dr. Mitloehner, to give us a bit of a primer on the chemistry that’s involved here.


Dr. Mitloehner:         Yeah. So, methane is CH4, and it’s a gas that is indeed very potent as a greenhouse gas. However, when looking at methane, we have to think about where does the carbon in the methane that we’re also concerned about — where does it come from, and where is it going?


                                    Where it comes from is atmospheric CO2, atmospheric carbon dioxide, which, during photosynthesis, makes it into plants. The plants suck it in, and then those plants convert some of that carbon from atmospheric CO2 into carbohydrates, such as cellulose or starch. Sooner or later, a bovine comes along and eats, and then a portion of that carbohydrate it ingests will become methane. That methane, however, stays in the atmosphere for a relatively short period of time — 10 years — and is then converted back into CO2, which then goes back into the cycle as plant food and so forth. So, it is a cycle called (the) biogenic carbon cycle, which is very different from fossil carbon, let's say, from fossil fuel extraction and use, which is carbon that was in the ground for a very long time (that) has been extracted, burned and, therefore, is now a new additive to our atmosphere.


                                    So, biogenic carbon from livestock versus fossil carbon from fossil fuel use are very different with respect to how they contribute to actual warming. Just to give you one idea here — because people are exaggerating the impact of livestock — in the United States, all beef production contributes to about 3% of all greenhouse gases (and) all dairy production to about 2% of all greenhouse gases. Okay? So, this is in the United States. Globally, all beef contributes to 6% of all global greenhouse gases and the dairy industry to 3% of all global greenhouse gases, just to give you a general idea. And one last thing: I just told you beef contributes to 3% in the United States. Contrast that to the fossil fuel sector contributing to 80% of all greenhouse gases. I view this campaign against animal agriculture as a smokescreen by those who are really mega-producers of pollution.


Tom:                          Okay. Let's dig into some of the discrepancies. You published a white paper; it’s titled, “Livestock's Contributions to Climate Change: Facts and Fiction.” And in this paper, you cite a claim that U.S. livestock greenhouse emissions from cows, pigs, sheep and chickens are comparable to all transportation sources. You found a very different picture. Tell us about that.


Dr. Mitloehner:         Yes. So, the different picture is that those people who painted that picture comparing livestock to transportation used one methodology to look at the impact of livestock on climate and a different methodology to look at the impact of transportation on climate. Let me explain. For livestock, they use what's called a lifecycle assessment, in which you look at all components of producing, let’s say, a pound of beef or a gallon of milk on climate, including the soil where the plants grow. The plants themselves that are then ingested by animals, the animals then produce some greenhouse gases themselves during enteric fermentation, meaning they are belching it out or their manure produces some. And then, sooner or later, the product makes it from the farm to the distribution center, from the distribution center to the processing center, and so on. Eventually, it ends up in a commercial restaurant or in your kitchen at home. A lifecycle assessment looks at the impact all the way from cradle to grave, meaning from the field to the fork. And that's the way it should be done. And the organization that made this comparison did that for livestock and they did it well. But when they compared livestock to transportation, they made a big mistake: namely that, on the transportation side, they didn't do a lifecycle assessment, but they only looked at direct emissions coming out of the tailpipe of vehicles — not the production of cars, trucks, trains, planes, ships, streets, harbors, airports and so forth. By doing so, they truly compared apples to oranges, using one methodology for the one and another methodology for the other. And as I said, they later corrected that comparison.


Tom:                          So, when we’re talking about climate change, why is it important to actually avoid comparing livestock emissions with those from other main sources of greenhouse gases?


Dr. Mitloehner:         Well, first of all, I think agriculture appreciates its contribution to a warming climate. We are contributing greenhouse gases, and we are actively involved in reducing those. So, that's just a little prelude. But comparing livestock to, let’s say, transportation, or power production and use, or the cement industry or so on is a dangerous exercise. And the reason is that the main greenhouse gas from livestock is methane, and methane undergoes cyclical conversion into CO2. So, it is atmospheric CO2 going into plants, going into the animal, and then that goes back into the atmosphere as CO2 again. So, this is a relatively short life cycle. As long as you don't increase livestock herds, as long as you keep them constant, you're not adding new additional carbon to the atmosphere. Okay? This is really important. As long as you do not increase livestock herds, you're not adding new additional carbon to the atmosphere.


                                    But every time you use fossil fuel, you extract carbon from the ground in the form of oil, coal and gas. You are burning it, and you're converting that into CO2, and that CO2 has a lifespan of 1,000 years. Meaning every time you use fossil fuel, let's say, by driving a car, you are adding new greenhouse gases to the existing stock that's already there. So, livestock is cyclical and its impact is relatively short-lived versus fossil fuels, (which) are not cyclical. That's a one-way street, from the ground into the air, and its impacts are long-lived.


Tom:                          You argue that, in fact, the U.S. livestock sector has shown considerable progress during the last half-century in reducing its environmental footprint. Tell us about that.


Dr. Mitloehner:         Well, yeah. There's no doubt about that. So, for example, on the dairy side, back mid-last century, 1950, we had 25 million dairy cows in the United States. Twenty-five. Today, we have 9 million dairy cows. So, a large reduction of cows. But with this much smaller herd today, we are producing 60% more milk. Sixty. Sixty percent more milk with much fewer cows. And that equates to a two-thirds reduction of greenhouse gases from the dairy sector. On the beef side, we had 100 and — so, in 1970, we had 140 million beef cattle. Today, we have a little over 90. So, much fewer beef cattle. Fifty million fewer. But even though we have 50 million fewer cattle, we're producing the same amount of beef. The progress we have seen in this country is remarkable. We are producing 18% of all beef globally with 8% percent of all cattle. That is remarkable.


Tom:                          It is truly a model of efficiency. And is that, indeed, what has brought this about: science-driven efficiency?


Dr. Mitloehner:         Partly. I think there are four main tools that the animal agriculture industries have used. One is research and development in the area of genetics, using better genetic material for both plants and animals. The second one is that we have improved reproductive efficiencies in livestock. The third one is that we have installed a veterinary system that can both prevent and/or treat diseases. And last, but not least, we have developed a feed system, a nutrition system, that optimizes nutrient use for livestock and poultry. And the combination of these four — of genetics, of reproduction efficiencies, and improvements to the veterinary system and the nutrition system — the combination of those four has allowed us to shrink our herds to historic lows (while) producing more than we ever have before.


Tom:                          What would you say needs to be improved right now? How can we get accurate and fair emissions assessments so that we're on the right path to solutions?


Dr. Mitloehner:         Well, that’s a really important question, and if you ask a scientist what needs to be done, a scientist will tell you, “Listen, you know, there is not enough funding in this field.” And I'm not different. I’ll tell you it is dismally small, what the public sector pays to get information on the impact of our food supply chain. There hardly is any funding, and there's very little funding in the private industry sector as well. And the reason why that matters is because of the lack of funding, most scientists just keep the fingers on their hands off that type of research when, indeed, it's urgently needed and constantly in the media. I would hope that particularly the public sector, federal and state agencies, would support investigation into the true impacts of livestock and into, also, research that further reduces those impacts.


Tom:                          Earlier, you mentioned the FAO, the U.N.'s food and agricultural organization. The FAO has formed an international partnership project to develop and adopt a gold standard of lifecycle assessment methodology for each livestock species in the feed sector, and that’s been a few years now. Where does that stand today, and is it, in your opinion, making a difference in the public's understanding of the role of livestock in the production of greenhouse gases?


Dr. Mitloehner:         Yeah. So, this project is referred to as LEAPP, and that stands for Livestock Environmental Assessment Performance Partnership. And this partnership is comprised of three sectors: governments, on the one hand, and then NGOs (non-governmental organizations) and the industry sector. So, that’s all livestock, poultry, feed and so on. And that’s under the auspices of the FAO, and I was actually the first chairman of this committee. And we developed many guidelines on how to do a proper lifecycle assessment for livestock, for feed — not just for greenhouse gases, but also for nutrients, for biodiversity, for water use and so forth. In this context, we have developed, I would say, at least one dozen guidelines that are now considered the global gold standard for LCA, for lifecycle assessment. And I think that, as a result of that, accurate quantification has really taken off.


                                    It's really important that the public understands that nobody is sitting on their hands — that there are active measures (being) taken to find ways to accurately quantify and further mitigate emissions from animal agriculture, from agricultural overall. The agricultural sector is very involved but, unfortunately, (is) oftentimes behind the curve in communicating this.


Tom:                          In your white paper, you make note that all regions have unique demands and abilities and, thus, require regional solutions. So, taking the United States as a as a model, as a microcosm of the globe, is U.S. agriculture presently structured in a way that would accommodate a more regional approach, or does this imply the need for a restructuring and better coordination?


Dr. Mitloehner:         Yeah. So, the United States is indeed the most efficient of all agricultural systems in the world. I don't think there's much debate about that, but that's not to say that what we do here and how we produce, for example, animal-source foods in the United States could be a model for all of the rest of the world. We could be a model for much of the developed world, but not for much of the developing world, where efficiencies, first of all, (in) livestock production are much lower, but that's largely a result of a lack in infrastructure. So, for example, I told you already that we have 9 million dairy cows here in the United States. In India, they have 300 million dairy animals, both cows and buffalo. And it is a religious belief that eating bovines is a sin. So, they don't eat cattle, but they have a lot of them. So, we're not proposing or suggesting that they should change their religious belief system, but we are suggesting that if they want to meet their nutritional needs and use cattle to do so — for example, (via) dairy products from cattle — then they could do the same that they do currently with one-quarter of the current cattle population, because having such massive number of animals does have a considerable environmental footprint, one that can be strongly reduced. And we here in the United States — scientists, practitioners and so on — can assist other people throughout the world, other nations throughout the world, (to) become more efficient. For example, we can assist them in building a veterinary system, or we can assist them in building a nutrition sector or a genetics sector that's really called for, and it needs to be done in a very sensitive way, where we work with these different places to develop what's right for their respective region.


Tom:                          The challenge, Dr. Mitloehner, of supplying food to a drastically growing human population is foremost on the minds of researchers and organizations concerned with nutrition. A Planet of Plenty, (for) example, is the aspirational goal of Alltech. Do you believe such a goal can be achieved — and, if so, sustained?


Dr. Mitloehner:         Yeah. That is a very important question. You know, I just turned 50. And when I was a little boy, we had about 3 billion people in the world. Three billion. Today, we have 7.6 (billion). By the time I'm an old man, we’ll have 9.5 billion people. In other words, we will triple human population throughout our lifetimes. And at the same time, we don't really triple natural resources to feed those people. In other words, we have to. It is imperative that we do drastically increase production of food for a wildly growing human population, because if we don't, we'll have some big problems on our hands.


                                    Can it be done? Can we produce more with similar inputs as we do today? The answer, in my mind, is yes. We have shown it, for example, here in the United States over the last 60 years. We have kept the inputs for animal agriculture constant, but we have tripled the outputs. Tripled the outputs. I mean, that is just an unbelievable success story. And, (as) I told you, we cannot transfer the U.S. model to the rest of the world, but we can assist others in drastically improving. For example, a country like China, which produces half of the world's pigs — 1 billion pigs per year — has a pre-weaning mortality (rate) of 40%. They are losing 400 million pigs every year (during) pre-weaning, and that is just a travesty and something that's totally unnecessary. We can help the Chinese. We can help the rest of the world do much better without really sucking up a lot (of) additional resources. We can do more with less, and that's at the core of sustainability.


Tom:                          Dr. Frank Mitloehner, professor in the department of animal science at the University of California, Davis. And we thank you so much for joining us.


Dr. Mitloehner:         Well, thank you so much for having me. Appreciate it.


Tom:                          This is been Ag Future, presented by Alltech. Thank you for joining us. Be sure to subscribe to Ag Future wherever you listen to podcasts.



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