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Kleinman Center for Energy Policy

COP27 Dispatch: The Struggle for Agricultural Sustainability Under Climate Stress

Andrew Hoffman, dean of Penn’s School of Veterinary Medicine, explores the intersection of climate change, agricultural sustainability, and food security.

Interview by Andrew Stone

November 20, 2022

Andrew Hoffman, dean of Penn’s School of Veterinary Medicine, discusses COP27’s focus on the global food system, and the pressures that climate change is placing on food production. He also highlights research at the School of Veterinary Medicine into the intersection of sustainable agriculture and food security.

Andy Stone: Welcome to the Energy Policy Now podcast from the Kleinman Center for Energy Policy at the University of Pennsylvania and to this special series on COP27, which is underway in Sharm El Sheikh, Egypt. Over the two weeks of COP, I’m holding short conversations with experts from the University of Pennsylvania on a number of key issues that are being discussed at this year’s Global Climate Change Conference.

In this episode, I’ll be talking with Andrew Hoffman, Dean of the University of Pennsylvania School of Veterinary Medicine which has been involved in research into the intersections between sustainable agriculture and food security. The issue has also been high on the agenda at this year’s COP, as climate change presents a growing threat to global food security. Andy, welcome to the podcast.

Andrew Hoffman: Thank you.

Stone: I wonder if we could start out very generally. I’d like to ask what is the interest of a veterinarian and of a veterinary school in the sustainability of the food system?

Hoffman: Yes, that’s a very common question, actually, and I think it isn’t necessarily intuitive to the public or even the academy. The veterinarians are of course very much impacted, along with our stakeholders. If you think about it, we are tasked with providing healthcare services for animals, advocating for public health, and of course as stewards of natural resources, including the great biodiversity of our planet Earth. So our profession is really, I think, most emblematic of the one-health framework, the inextricable link of the health of animals, humans, and the environment. And we live in that world every single day. Whether we’re in the exam room, we are thinking about the environment of animals. When we’re discussing disease problems or if we’re on the farm, we’re thinking about impact of climate on croplands and livestock, poultry, productivity and health. And then, of course, there’s enormous crossover between public health and veterinary medicine related to climate.

Climate is driving spillovers of infectious diseases, particularly viruses from animals into the human population as we all evidenced in the coronavirus pandemic. So climate intersects with all these different issues, in particular agriculture, food, health, and biodiversity.

Stone: This is all really an issue at this point today or more intensely so because we’re at a time when the population is growing very rapidly, the global population. And simultaneously, the productivity of some agricultural land is on the decline. This is more on the crop side, but I’ve seen statistics that say that the agricultural land productivity in Africa has actually declined by a third over the past half-century. Does that play into animal health, as well, or animal husbandry?

Hoffman: Absolutely, it’s sometimes a forgotten area, but when you look at the desertification and abandoned land inventory, in particular in the global South, and as you mentioned, in Africa, there are some estimates of over a billion acres of abandoned land. A good part of that relates to the effects of climate change. The process by which indigenous people are no longer able to farm those areas is a gradual process. And during that process of many years, many decades, there are a number of challenges to animal health, and the dependability of small-holding farmers — which are the majority of the farmers on Earth — to depend on their livestock for nutrient-dense food.

So as the lands start to dry up, as waterways start to dry up, where the quality of water degrades as soils degrade, as the ability to sustain grasslands or crops, it gets more and more challenging for farmers to stay where they are. So migration is inevitable. Displacement of people is inevitable. And in that transition, animal health can be seriously compromised.

There is, of course, the occurrence of direct impacts of heat stress, which needn’t be explained, but there are more nuanced effects of poor water quality resulting in diseases just like we see in humans — diarrheal diseases and diseases that impact the overall productivity, output, growth, and even survival of those animals. There are more incursions of infectious diseases that are transmissible. There are more emerging zoonotic diseases that get transmitted from the animals to people — which is also compromising of the ability to use that land, the ability to remain productive as a farmer in that location. So there are just a lot of intersections between farmers farming and animal health that occur with challenges to land use.

Stone: It’s very interesting because when I think of infectious disease, I think about it in the human context. But you’re saying here that the pressures of climate change are also increasing the incidence of infectious disease among animals.

Hoffman: I think one example that’s happening this month is really substantial flooding in Australia. And the flooding has brought just teems of mosquitoes. The mosquitoes are vectors for a number of infectious diseases that are transmitted to cattle, and then the cattle can act as a reservoir for those diseases.

So I think it’s really important that we understand that any sort of major ecosystem challenge can result in vector-borne food and waterborne, airborne, and of course direct animal-to-animal and animal-to-human transmission of diseases. Or even poor quality, reduction in the quality of those products that people rely on for nutrition. And as a result, we have a lot of people in hunger in those areas. But you know, if you just look at that instance with mosquitoes — but you could look at that around the world. Any time there’s flooding, as in Pakistan, for example, there are really major impacts, not only on the survival of livestock, but on their health.

It could be anything from just their general health, in that flooding results in near-drowning, and when the animals experience flooding, of course they have problems with their feet, they have problems with the legs, their skin, and they have problems finding food. And they become dehydrated, and so on and so forth. So it’s sort of the hidden side of extreme weather and climate change challenges to the livestock sector that people don’t really hear about, unless you really kind of look for it.

Stone: What are some of the specific initiatives at the vet school that are seeking to improve agricultural system sustainability?

Hoffman: Yes, thank you for that question. I think it’s really important from the veterinary perspective, and I think holistically — if we’re going to help countries, and we’re going to help people farm around the world — we have to first acknowledge that it’s very much context-dependent. I think it’s very important that the work that we do is generalizable but very much in the context of U.S. agriculture. So let me just start with that.

So the work that we do is holistic, in that we have programs of research and outreach in the areas of animal health, focused on, for example, antimicrobial resistance, which is why they call it “the hidden pandemic,” or “the next pandemic.” It’s the transmission of organisms from foodstuffs to people, or between livestock, or between people that have organisms that are resistant to antibiotics. So antimicrobial resistance and animal/human health.

We have researched importantly and relevant to COP27 in the mitigation of enteric methane from ruminants. So we have a fairly substantial program funded through the USDA, and our investigators, led by Dipti Pitta, who is a Professor of Ruminant Microbiology and Nutrition, is concentrated on ways of raising cattle from a very young age that are, through the use of probiotics and other supplements, are low methane producers. And also selecting cattle genetically that are low methane producers. And trying to understand all the mechanisms and factors that contribute to enteric methane from a dietary and environmental standpoint.

Another area that’s very important is in the area of mitigating food waste. Steve Finn at COP talked a lot about food waste all along the demand and supply chain where there are opportunities to abate food waste. Our research is on how dairy cattle can up-cycle food waste. This is human fruits and vegetables that are rejected from the wholesale and retail markets that can be fed to dairy cattle. Instead of feeding them rations that are produced from croplands, we can supplement their food and reduce the amount of crops and therefore the land use that goes into producing the crops that feed cattle. We can feed things like oranges and other products that are thrown out. And as we replace the dry matter in the form of wasted food, we find that the cattle of course thrive, and their output of milk is very good. The other important thing to think about that research that won’t actually be that intuitive is that if those fruits and vegetables are thrown out into a landfill, which is where they normally go, there is a much, much greater amount of methane that’s produced from the landfill.

If cattle are allowed to be fed this material, then it gets rapidly, and in an accelerated way, decayed in the cow’s stomach, and it replaces the land use, and it replaces the methane that comes from the landfill. And that generally, our data shows that that largely offsets the amount of enteric methane that cattle are making.

So by contending with food waste, by up-cycling food into dairy cattle, we can curb emissions fairly substantially from the dairy industry. We have programs in animal welfare. They look at animal welfare and behavior. We have one of eight UPenn online Masters. It is entitled, “The Masters in Animal Welfare and Behavior,” and that is, of course, central to our efforts.

And then we have global and regional bio-surveillance, disease surveillance systems that are absolutely essential to maintain animal health and productivity in these systems. So those are some examples of some of the things that we’re doing.

Stone: I want to jump back. You mentioned a couple of minutes ago Steven Finn, who also is with the University of Pennsylvania. You mentioned food waste. On Thursday, a couple of days ago, he was on this podcast talking about food waste. So whoever may be interested in that issue, please listen to that episode.

You also talked a moment ago about using probiotics and other ways to reduce the methane emissions, or you said “enteric emissions” from cows. And on the mitigation side, agriculture of cows and sheep has been brought up as major sources of methane, a major greenhouse gas. To what extent can the methane emissions — if that’s the correct word — from livestock actually be reduced through changes in diet and, as you also said, I guess breeding of cows to have cows that emit less.

Hoffman: Yes, and that is a subject of investigators around the world. We recently launched in October the Center for Stewardship, Agriculture, and Food Security as a version 2.0 of our Centers on Animal and Health Productivity. That’s a big focus of ours, addressing enteric emissions. Enteric emissions from cattle — that means beef cattle and dairy cattle largely, but also small ruminants — is somewhere around 5-1/2 to 6% of total emissions in the United States out of a total of, according to EPA, 12% of total greenhouse gas emissions for U.S. greenhouse gasses. And that is apart from land use calculations.

So it is a substantial amount, and so I think it warrants an important program, an important focus on that area. The enteric emissions can be curbed in a number of different ways, as you can imagine. Everything from the constituents of the diet, ranging from the actual protein and carbohydrates just as substantial building blocks of a diet, to trace minerals, to oils, to other types of supplements that can be used to boost the caloric or protein intake of the animal.

So in other words, like configuring the actual diet in appropriate ratios can achieve a lower methane output. But importantly, I think, methane comes from methanogens, and these are certain bacteria in the rumen or the cow, in the forestomach of the ruminants. They are a critical part of the digestive process, of the early digestive process in the forestomach of cattle. But also it’s not entirely necessary for the cattle to be producing the type of methane that they are producing unabated.

So there are several supplements that are out there. The famous one we’ve heard about is seaweed, but there are also several other small molecule supplements that are safely administered to adult cattle, both beef cattle and dairy, that will reduce methane production anywhere from 30 to 80%. This is very context-dependent. It depends on the type of operation. It depends on the stage of feeding and the age of the animal and the diet they’re on and so forth. It depends on if they’re high producers or low producers and whether they’re on byproduct feeds or not.

But yes, there’s great hope that actual supplementation could certainly help us mitigate the enteric emissions in a scale and a timeframe that’s consistent with 50% reduction in emissions from that sector by 2030. But there are also other ways to do this. Another way I mentioned, probiotics, is to start a calf at a young age on probiotics that actually substitute or out-compete for adherence and ultimately the residence of methanogenic bacteria in the forestomach. So that’s another strategy, is to actually put bacteria in there that out-compete the methanogens.

So I think there are different strategies. One is to raise cattle with probiotics. One is to select cattle that are known genetically to harbor lower methanogens that are also high-producers. And the other is to provide supplements or dietary shifts in the adult animal. So there are lots of different strategies being looked at, and let’s not forget that they make manure, and the manure has to be utilized for fertilizer and spread out, or has to be digested anaerobically in a system that would curb the emissions from manure. Manure produces nitric oxide, as well as ammonia.

So there are lots of efforts in contending with the outputs of cattle, the manure output, as stored, as well as used as fertilizers to reduce the greenhouse gas emissions from that component, which is pretty much the other 50% of emissions from cattle.

Stone: Now the food and agriculture system has been a focus of the COP process. What developments have you seen or did you see during your week at COP last week related to again, the agricultural system? And is there anything that gives you hope that some of the adaptations and mitigations we’ve been talking about will come to pass through the COP process?

Hoffman: Yes, and again it’s very context-dependent, but I think the FAO, of course, has the Koronivia Joint Work on Agriculture, and one might just say that COP27 was really the first serious ag and food COP. Koronivia has been around for a while, but it has really not been developing draft decisions that have advanced adaptation, mitigation and resilience recommendations for countries, and particularly those that are most vulnerable and so forth.

So I think what happened here was that there was a substantial effort on the part of the FAO to have a program focused on agriculture and food security under the UNFCCC. And they essentially mainstreamed agriculture in the U.N. processes, through the Koronivia Joint Work on Agriculture. There were many meetings of the Koronivia Working Group, as well as side meetings, as well as many pavilion panels and partnership discussions that related ultimately to the plans that are going to be drafted, the recommendations that are going to be drafted as a decision and as an outcome — as an output, let’s say — of the COP27.

I think some of them specifically relate to the fact that there’s a desperate need for knowledge, scaling up knowledge, technology transfer, and of course financing for agriculture and food systems, particularly in more vulnerable nations and in particular Africa. There’s a lot of discussion about — I think it’s fascinating and it’s important to recognize that Africa has spoken, and Afrikaans have spoken about how they want to move forward on agriculture. It is not for us to decide in the U.S. to decide on how Africa moves forward on agriculture. It is important that loss and damage financing is discussed in this context. And it is important that the global North countries, particularly those that have contributed most to emissions, participate in loss and damage financing.

So that’s, of course, a very important part of the discussion around agriculture and food. And in terms of the actual implementation, there’s a lot of discussion on agro-ecology and agro-biodiversity as a central paradigm around how agriculture is going to transition and how food production will be scaled up. And that involves both croplands, as well as the livestock and poultry sectors.

Stone: Andy, thanks very much for talking.

Hoffman: Oh, it has been a pleasure. Thank you so much.

Stone: Thanks for listening to this special episode of the Energy Policy Now podcast, with perspectives from COP27 in Sharm El Sheikh, Egypt. This is the final episode in our series from and about COP, but you can continue to tune into the Energy Policy Now podcast for conversations that run the gamut of energy policy issues. Check out Energy Policy Now on the Kleinman Center website, on Apple Podcasts, Spotify, or wherever you get your podcasts. And to keep up with research and events from the Kleinman Center, visit our website. 


You can listen to the full interview here

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