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Welcome to Episode 9 of The Spokesman Speaks podcast. In this episode, nationally-recognized air quality expert Dr. Frank Mitloehner (an animal science professor at UC Davis) challenges misinformation about the environmental impact of livestock production and meat consumption. The episode also includes an important update on EPA's Waters of the U.S. (WOTUS) rule.


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Narrator: Since 1934, Iowa's farmers have turned to the Iowa Farm Bureau Spokesman as their trusted news source. Now, The Spokesman Speaks. Listen in and hear from leading experts on topics important to farmers and agriculture. Now, here's your host, Laurie Johns.

Laurie Johns: Welcome to The Spokesman Speaks Podcast. This is our March 25th edition. We're glad to have you here. This week we're going to feature an interview with UC Davis Professor Dr. Frank Mitloehner, who's going to help us challenge that misinformation about environmental impacts of livestock farming. The episode also includes an important update on a federal rule that Iowa's farmers have been working on to improve for years. But let's start with Dr. Frank Mitloehner who is an animal science professor at UC Davis and he is seen as one of agriculture's leading air quality experts. If you follow him on Twitter, you're going to know that he's not afraid to speak his mind. In fact, he recently shared that Congresswoman Alexandria Ocasio-Cortez's team reached out to him for an hour-long conversation on ag and climate change. You can imagine how that one went. Iowa Farm Bureau's Caitlyn Lamm caught up with Dr. Mitloehner at the Pork Congress earlier this year and as you're going to hear, they cut right to the chase. Is a vegan diet really better for the environment? Let's listen in.

Dr. Mitloehner: Let's say next year you would consider becoming a vegan. Then your carbon footprint off this year, the omnivore diet versus the next year diet, the vegan diet, would make up a difference with respect to your carbon footprint, that equals one flight from Iowa to Germany. One flight, international flight, generates the same carbon footprint emissions as a change from an omnivore diet to a vegan diet.

Caitlyn Lamm: Why do we hear different numbers when it comes to greenhouse gases and livestock's impact on that? What's the correct number and why are these numbers also different?

Dr. Mitloehner: The main difference is that people do not really differentiate where those emissions occur. Some people use global numbers, some people use national numbers. For example, many people in the anti-animal agriculture arena will use global numbers to depict the impact of animal agriculture. The global number for all of livestock globally is 14.5 percent. That's how much greenhouse gases come from all of animal agriculture according to the FAO, the Food and Agriculture Organization. Here in the United States according to the Environmental Protection Agency, which looks at admissions across all sectors of society including transportation, power, production, U.S. agriculture, according to the EPA, electricity production and use makes up about 30 percent of all greenhouse gases, transportation about 27 percent and animal agriculture less than 4 percent. So, the number for the United States, all of livestock in the United States, is 4 percent. And that includes pigs and beef and dairy and chickens and so on. And that's the official number for the United States. So please, when you report on livestock for this country, use the appropriate national number, which is 4 percent and not the international number, which is 14.5 percent. No matter what your agenda is, stay with the facts.

Caitlyn Lamm: So, then there's not too much incentive for meat lovers to stop eating meat?

Dr. Mitloehner: I think there is always an incentive to be reasonable about how much you eat and what you eat and so on. And that's true for any diet. In my opinion, the diets that damages us the most health wise are caused by food items that are very calorie dense. Many people, including some recent reports, favor us to produce more calorie dense foods, more carbohydrate rich foods. The last thing in the world we need in a country like ours is more calories. In fact, we have too many calories which is reflected by an obesity epidemic and increasing rates of diabetes and so forth. We don't need more calorie dense diets. We need more nutrient dense diets. And what gets us there is not high carb diet but diets high in animal-based food items.

Caitlyn Lamm: We've also heard, "Well I don't want to go completely vegan or completely vegetarian so I'm just going to go ahead and eat only grass-fed beef." So, is that something that takes away that environmental impact of animal agriculture?

Dr. Mitloehner: I think there are reasons to look into grass-fed beef. You know, there are certain aspects of grass-fed beef that appeal to people. The environmental portion I think is not so much particularly on the greenhouse gas side, one that should, that would convince me to go that road. And, and the reason is this, if you compare, let's say a grass finished steer versus a corn finished steer, then we know both of them spent the majority of their lives on pasture. Even the corn finished animal was on pasture for two-thirds of its life before it then went into the feedlot for the last four months of its life. That's how long they are normally in a feedlot. The corn finished animals go to slaughter around 14, 15, 16 months of age and the grass finished steer will go to slaughter at approximately twice that age. So, 26 to 30 months of age. This difference in lifespan of the grass versus the corn finished animal means that the grass finished animal has way more time to produce Interra gases like methane or produce manure or eat or drink and so on. So, the environmental footprint of the grass finished animal is not necessarily a lower one. And there's another aspect that's an important one. Methane, the greenhouse gas methane, is derived from the amount of roughage that an animal invests. The more roughages in the diet, the more methane that animal produces. So, by definition an animal that's grass finished will consume more roughage compared to a corn finished steer and that will have an impact on the methane coming off of those animals. So, the carbon footprint would not sway me to become a grass finished beef eater. There are other issues though that are also of interest. So, I think everybody should eat whatever they desire and there are reasons why people feel A is better than B. And what we as scientists can do is guide you to make the decisions that are right for you.

Caitlyn Lamm: We're here in Iowa, we're the number one pork producing state, we actually have a festival that's completely devoted to bacon. So what types of improvements have you seen specifically with pig farming that have reduced any type of environmental effect? Are we more efficient now than we were then raising pigs out on pasture?

Dr. Mitloehner: Well, there's absolutely no question about that either. You have been a master of efficiency gains. You have tripled productivity over the last 50 years here in the United States and particularly in Iowa. That has drastically reduced your carbon footprint, your water footprint, your everything footprint. However, you're not getting the credit you deserve. In fact, you are portrayed by much of society as being the least sustainable and the most intensive and so on. And I think the opposite is true.

Caitlyn Lamm: And so, if people really want to make a change that involves food you've mentioned before that a decrease in food waste would be a better option for that then for going a certain type of food.

Dr. Mitloehner: Well, we have a huge issue, not just here in the United States, but globally. By wasting 40 percent of all food, four zero, 40 percent of all food is lost and is going basically to landfills. And that is an issue of major concern, not just for me, but many of my colleagues as well. What's interesting here is that if you look at the different food items that are being eaten, those high in vegetables and fruit are wasted the most because these food items are very perishable. 50 percent of vegetables and fruits are wasted. Animal-based diets or animal-based food items are wasted at a rate of 20 percent. That's still way too high, but much better. And I think no matter what you produce and no matter what you consume, we can do a much better job in wasting less.

Laurie Johns: Well that's certainly great advice and it's great perspective from the Doc. Don't you think? And it comes at a perfect time. It seems like we're just bombarded with misinformation in the media and the political arena regarding the environmental impact of livestock. Speaking of good timing, who's ready to hear some good news about EPA's Waters of the U.S. Rule? That rule that farmers have been working to improve for years. Farmers have a lot of questions about the Waters of the U.S. Rule, where we are, what they need to know what's next? There’re so many questions. I know for my questions, I go to our guests that we're having today. Christina Gruenhagen, our legal counsel with our government relations division. And I tell you what, Christina has tons of information on this particular thing. So, we're going to, in at least our time that we have here, hit some of the basics because I think folks out there listening right now would like to know that. Chris, first, welcome. Nice to see you.

Christina Gruenhagen: Good to be here, Laurie.

Laurie Johns: So, Waters of the U.S. It seems like something we've been working on for quite some time and all the farmers out there might feel the same way. But where is that rule right now?

Christina Gruenhagen: Well, the 2015 Obama rule now is still being litigated in the courts. Georgia, Texas and North Dakota have cases that are pending right now and we're waiting to see what happens with those. The EPA and the Corps of Engineers has also proposed a rule to repeal the 2015 rule and put back the old rule. That rule is still pending but we expect that to be finalized yet this year. And so, step two of that and the big part of why we're talking today, it's the new 2019 rewrite of the Clean Water Rule. This is a rule that decides where the federal government has jurisdiction under the Clean Water Act. So, with the EPA, it's whether you have to get a federal MPDS permit for a discharge or with the Corps of Engineers if you have to dredge or fill a wetland. So, it'd be like if you're putting in a conservation practice next to a stream, those kinds of things. The Corps of Engineers requires a permit for that.

Laurie Johns: This is a time sensitive issue. It's a priority right now. Timing counts, doesn't it Chris?

Christina Gruenhagen: Yeah. We want to talk about this with you today because April 15th is the comment deadline on the new rewrite. Now, while the repeal rule is still pending, the litigation is still pending, what's most important right now is that farmers need to get out and comment on the rule by April 15th.

Laurie Johns: So, I mean, it comes down to defining this new rule. There’re six different definitions of waterway of what water is and six seems a heck of a lot easier to understand than however many pages that were with the original, with the Waters of the U.S. Which is part of the problems that everybody had with it.

Christina Gruenhagen: Yeah. Well this proposal is certainly a lot shorter as far as the number of pages go. But there are six categories of water. Some of them are familiar, some of them are new. One is just your traditional navigable waters, you know, like the Mississippi River that you would be able to take a barge down with your grain, of course. Tributaries is a second area. This definition with streams is a little bit different than the previous proposal. This one only talks about perennial and intermittent streams. So, the stream has to have flow in it. In other words, at least some of the time. The ephemeral streams which only have flow after precipitation, those are no longer going to be Waters of the U.S.

Laurie Johns: That's good.

Christina Gruenhagen: Yes, but they're going to be, they can be still regulated by the state of Iowa. But they wouldn't be regulated by the federal government. And these are things we were concerned about previously, our erosion features and fields. You know when you have a small gully after a rain in your field that that shouldn't be a water, should I say, land that's regulated by the federal government.

Laurie Johns: Yeah, cause sometimes you're talking about fields that have been farmed for generations and in a family, and look at the unpredictable weather we're having, not just now but year-round, and you get four inches of rain and now there's a big pond on there. Well that doesn't mean you're going to put in a canoe and get to Raccoon River there.

Christina Gruenhagen: So, this definition is better than the previous one, but we still have some questions and think maybe it can get a little bit clearer between what's an a femoral feature on the landscape versus an intermittent stream.

Laurie Johns: Here we are today, and we have the Clean Water, Clear Rules and that's the effort that we're trying to get out there. So, for farmers listening to this right now, no matter what they grow, what they raise, this is going to affect them.

Christina Gruenhagen: Yes.

Laurie Johns: So, what should they do?

Christina Gruenhagen: Well, they should comment on Clean Water, Clean Rules. We have an online petition that you can sign. A really quick and easy way to go ahead and comment in support of the rule that, you know, this is a lot better than the other one. Or you can go to if you want to read the whole rule and just search for Waters of the U.S. and you can read it and provide your own detailed comments if you'd like.

Laurie Johns: Now, how long is that rule? You've got to figure out how much reading time someone's going to need.

Christina Gruenhagen: It's about 67 pages of really tiny type. So, you do need a bit of a magnifying glass but it's a little bit better than the last one.

Laurie Johns: I'm going to have to find my readers for that one. I don't know if I can, do you know what, I'm just glad that we're bringing you in here because you've got questions? Just ask Chris. Cause you know, really you have read this many, many times.

Christina Gruenhagen: I'd like to talk about one of the really big improvements in this rule is in the area of wetlands. This rule only applies to adjacent wetlands. The old rule had any water within 4,000 feet of a tributary was going to be covered. This is only adjacent wetlands, which is a huge, huge improvement. So, it eliminates a question of whether the mud puddle in the middle of your field will be covered.

Laurie Johns: Oh, good.

Christina Gruenhagen: These are wetlands that have to be adjacent to like a tributary and actually have to be abutting or touching that tributary. Or when the tributary floods, it reaches out and touches it. So, it really provides a lot of clarity in the area of wetlands as to what's covered and what's not.

Laurie Johns: They sure didn't have that in the first go round, did they?

Christina Gruenhagen: No.

Laurie Johns: Anything else that, too, you think is worth mentioning for folks that are out there listening right now?

Christina Gruenhagen: Mainly this is, this is step two of the process. Step one we're waiting on with repeal. Step two is this rule. And so, we hope that the administration can provide a little bit of additional clarity with it. But we're very pleased in the direction they're heading.

Laurie Johns: So, timelines, what do we need to know? What's next?

Christina Gruenhagen: The public comment period closes again April 15th. But the administration has committed to finalizing this rural by the end of the year, and when they're expecting over a million public comments, that's a really big goal.

Laurie Johns: No kidding. So be sure to start by visiting today and sign our Clean Water, Clear Rules petition. Thanks so much, Chris.

Christina Gruenhagen: Thank you.

Laurie Johns: If you're an Iowa Farm Bureau member, and we certainly hope that you are, be sure to check your mailbox this week for the special conservation section in this week Spokesman newspaper. There's lots of great stories there about efforts to improve water quality and the exciting progress that's being made. And you're a part of it. You don't want to miss it. That's all for this episode of The Spokesman Speaks Podcast. Be sure to join us for our next episode on April 8th. Until next time, thanks for reading The Spokesman. Thanks for all the great stories and inspiration, and thanks for listening to The Spokesman Speaks.

Narrator: Thank you for listening to The Spokesman Speaks, a podcast by Iowa Farm Bureau. Check out more podcasts and articles from The Spokesman at You can also find and subscribe to The Spokesman Speaks Podcast in the Apple Podcasts app, Google Play, and other popular podcast apps. We appreciate your ratings and reviews and welcome your feedback at



About The Spokesman Speaks Podcast

Since 1934,  The Iowa Farm Bureau Spokesman has been Iowa’s leading agriculture news source, and today it is the largest circulation ag newspaper in Iowa. While the Spokesman newspaper is available exclusively to Iowa Farm Bureau members, The Spokesman Speaks podcast is available publicly, reaching farmers on-the-go with stories that matter to them. You can find episodes of the podcast at or subscribe and listen in your favorite podcast app, such as Apple Podcasts, Google Play, Spotify, Stitcher or TuneInRadio.

We release new podcast episodes every other Monday. Episode 10 will be released on April 8, 2019.