Why we don’t all need to be vegans in the pursuit of sustainability

Humans are unique in the degree to which they can manipulate their surroundings. And agriculture is one enormous way to do that manipulating — triggering fierce arguments over the impact on the planet. So, when an Oxford University study was published in Science looking at the sustainability of farming and ranching practices, it was heralded with curious reactions.

Avoiding meat and dairy is the single biggest way to reduce your impact on earth,” read a headline in the UK Guardian, introducing the study published in Science by Joseph Poore, a zoology professor at Oxford, and Thomas Nemecek, a scientist at LCA Research Group in Zurich, Switzerland. Further, the Guardian quoted Poore as saying “A vegan diet is probably the single biggest way to reduce your impact on planet Earth, not just greenhouse gases, but global acidification, eutrophication, land use and water use.”

Poore’s study did indeed study GHGs, acidification, eutrophication, land and water use. But the paper does not conclude a recommendation of veganism. Instead, it calls for producers to monitor impacts, and find different ways to produce foods.

The study was a meta-analysis, a review of 570 studies of 38,700 farms and 1,600 processors, packagers and retailers. It found that agriculture has a massive impact on the planet—meat and dairy provide 18 percent of calories and 37 percent of protein, while using 83 percent of all farmland and generating 60 percent of agriculture’s greenhouse gas emissions. And it did look at the impacts on five environmental criteria according to production methods. But oddly, the paper’s conclusions—and the media pickup—focused on greenhouse gas emissions.

Poore’s study showed huge variations in production methods. Beef cattle raised on deforested pasture produced 12 times more greenhouse gas and used 50 times more than beef raised on natural pasture. And beef produced six times more greenhouse gases and 36 times more land than raising protein from peas, for example.

One method was grass-fed beef, introduced because it was considered more humane and ecological sustainable than other methods of feeding livestock.

And people who have long opposed eating meat picked up on the story. George Monbiot, a writer and environmental activist in the UK, tweeted that “the food campaigners meant well but got it wrong: switching from intensive meat to free range meat means less cruelty but even greater environmental destruction. The switch should be to a plant-based diet.” In a video, Monbiot expands on his case:

So, is all meat not only murder but murderous to the planet? Is veganism the only path to ecological sustainability?

Not so fast, according to UC Davis animal geneticist Alison Van Eenennaam. “Sustainability” will depend on what variable you are optimizing—is it greenhouse gas? Land use? Acidification? Cruelty? Productivity? They don’t always point in the same direction, she warned.

“The best solution is always a more efficient production system like the US,” Van Eenennaam said in an email interview with the Genetic Literacy Project. “And the use of technologies like implants and ionophores, which of course everyone freaks out about.” These technologies involve:

  • Growth promoting implants, such as growth hormones, that have been used for almost 50 years to improve growth rates by 10-30 percent, feed efficiency by 5-15 percent, and meat leanness by 5-8 percent). However, growth hormones and other implants have been criticized for being “unnatural” and possibly risky to health.
  • Ionophores, feed additives that alter how food is fermented and ultimately digested in the cow’s rumen and improve conversion of feed to lean muscle mass. Although ionophores are not “true” antibiotics because don’t outright kill bacteria but inhibit bacterial function, they have come under fire because of overall public concerns about antibiotics in the food supply.
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So far, technologies like genetic engineering have not yet been approved in cattle and nearly all livestock and may be unlikely to play a role given opposition from powerful non-governmental organizations.

A chart of productivity among different countries livestock from a “Dietitians’ Handout” by Van Eenennaam does point to a great deal of variability. Countries like the United States  and to a lesser degree, China do show greater tonnage of meat from a given number of cattle. Others, like India, Ethiopia and Sudan, show dramatically less productivity.

Another study, by Ray Hilborn of the University of Washington, and his colleagues, compared the environmental cost of animal foods in more detail and found wild, wide variations:

  • Greenhouse gas production was lowest in mollusk farming and smaller pelagic fisheries (salmon farming, white fish) and chicken, while catfish farms and beef were 20 times higher in GHG production.
  • Energy use was lowest in mollusk and small pelagic fisheries, but livestock was still lower than all other types of aquaculture (beef required less energy than shrimperies, for example).
  • Eutrophication was lowest in pelagic fisheries and mollusk and salmon farms, but higher in catfish and beef operations, though beef showed an extremely broad range of eutrophication.
  • Acidification potential was lowest for mollusks, and small pelagic, white fish and salmon farms at the lower level. Beef production had the highest acidification impact, mostly due to (again) high variability among beef production studies.

“There are striking differences in terms of the environmental impacts of different animal source food production methods,” Hilborn and his colleagues wrote. “Because the range of variability is quite high, any proposed policy must consider the specific species and production system.”

Another point Van Eenennaam makes is that removing cows from fields does not necessarily result in improved sustainability. Instead, it leaves a fallow field, full of plant matter that is inedible to us, that must be re-sown. Even some plants do not get off the hook. Asparagus, for example, consumes a dramatic amount of fossil fuels, and therefore emits far more carbon dioxide, because of requirements to transport the vegetable to markets.

Instead of veganism, looking at the best way to get a gram of protein might point to true sustainability. Protein—especially animal protein—is the easiest way for developing countries to raise living standards, by providing enough to eat more cheaply. However, a cow raised one way can be more sustainable than a cow raised another way. All food production involves tradeoffs; optimizing product quality and safety, improving animal welfare, and decreasing impact on the environment and using natural resources efficiency all require reducing one in favor of another.

There’s no free lunch.

Andrew Porterfield is a writer and editor, and has worked with numerous academic institutions, companies and non-profits in the life sciences. BIO. Follow him on Twitter @AMPorterfield.

16 thoughts on “Why we don’t all need to be vegans in the pursuit of sustainability”

  1. This seems like a pretty transparent attempt to muddy the waters. Going vegan is best for land use AND greenhouse gases AND dead zones AND deforestation AND protecting biodiversity AND greenhouse gases AND cruelty. A vegan can live off of one sixth the land used by an omnivore, meaning a lot of land can go back to being forest or lush prairie and fish stocks can recover worldwide.

      • Fine. Don’t go vegan. But would you reduce your consumption of meat somewhat if you had read the research showing that reducing meat consumption is one of the best ways to protect the health of the planet? Do you have children or grandchildren whose future is put at risk by our unwillingness to curb our appetites today (for consumption in general and meat in particular)? Are you saying you will do whatever the hell you want to even if it hurts others, or is there some room for compromise here?

        • I eat a lot of wild game. It is my primary red meat source. My land is overrun with deer. In the county where my land is, at fawn drop 2 years ago, deer population was estimated at 80 per sq. mile. We have so many we don’t have any forest regeneration going on. A seedling doesn’t have a chance unless it is fenced. Every tree I have planted is fenced or tubed and will be until large enough to withstand some browsing. What is interesting is that we have plenty of predators and yet way too many deer. Lots of coyotes, more bears every year and at least one wolf pack is hunting our county as well.

          • Feel free to come shoot deer anytime at my place. the rotten things are over running Florida.

          • Same thing in my neck of the woods, and even worse for some relatives up in Ontario, Canada.

            Huge deer overpopulation issue all over the province, but I will always remember a cousin berate me for not taking a shot at a wolf the last time I was out hunting.

            His reason: “They kill the deer!”

            I look back over the 6 guys in our hunting group, and the single buck we bagged, and just laugh, “They’re a lot better at it than we are, and saving the deer is the opposite of what’s needed.”

          • Same goes for back home in Michigan. A lot of friends have quit vegetable gardening because of them. There are ticks all over in the dunes near our old home in Muskegon. Because the deer seem to realize that they won’t be hunted near buildings. We need longer Doe seasons.

          • Or a larger wolf population.

            …yes I know that’s not going to happen simply because people are people, but I’ve seen the data, and they are far more effective than any managed hunting program…by far.

            The results from the reintroduction to Yellowstone and the surrounding area were so far beyond what even the ecologists were predicting. Having the wolves back caused immense changes among the prey species. The idea that they changed the course of rivers…well that was a bit of a stretch, but there were a lot of changes, and one of the biggest was t put the brakes on the growth of the deer and elk populations.

          • I used to live with a pack of wolf hybrids. Best companions I have ever had. Smart as can be. They watched everything I did. One learned when to pick and eat sweet peppers. They would husk and eat sweet corn. They scared off some riff raff a couple of times. Seems that a deep grumble from a 130 pound fella can intimidate.

          • Once again being a biologist, being able to observe the wild, domesticated, and hybrid individuals, is just fascinating.

            One friend with a high % wolf dog was surprised when I pointed out some of the big differences.

            Most people can easily see the difference in body language, and vocalization, but they miss some of the most important changes that have come about.

            Take almost any domesticated dog, but the breeds that have been developed to hunt or herd, get their attention and point.

            If they know you (so they aren’t more concerned with, “who’s this guy”), the odds are they’ll look where you’re pointing, not at your finger. Wolves, coyotes, dingos, jackals, and foxes won’t, most high wolf % hybrids won’t either.

            That is a huge difference, and a critical one for the roles we’ve bred them to perform.

      • You’re confusing two different indicators of land use.
        1) If everyone went vegan, that would use less land to provide food than would any other scenario. That’s what I was talking about and I was correct on that.
        2) A different indicator is to ask on what dietary pattern could the earth support the most people, and looking at things that way, some people still eating meat maximizes the use of the kinds of land we have (some land isn’t suitable for crops). But looking at things that way assumes a worst-case scenario where the population keeps growing and we’re trying to max out the productive capacity of the earth for food production. Our already too-large population is destroying the health of the earth in many ways, so we need to aim for a stable and then shrinking population that uses far less of the earth than we do now, and leaves lots of it as ungrazed grasslands and forests. That’s the approach that is best for the ehalth of the earth, not feeding the most mouths possible.

    • going vegan isn’t best for greenhouse gases either. fossil fuels far outstrip meat production, in greenhouse gas release (most credible estimates of total greenhouse gases released by meat production are around 14-16%. unfortunately, militant vegans make false claims as high as 60%, which is not backed by credible data). as for deforestation, much of the animals put on land that has been deforested, are there to ‘make claim’ on the land, to prove it is being used (in other words, the land wasn’t cleared to provide grazing, etc. for the animals, the animals are there to back a legal claim on the land). much of the land used for grazing meat animals is unable to produce crops, or provide other uses (outside the USA, most animals are grazed, not grain fed…which is why vegans often disingenuously overestimate the cropland used to feed animals). reduction in meat consumption is good for the environment, but vegans are hard to take seriously as they continually overestimate and mislead, when discussing the benefits of a vegan diet, while ignoring the hindrances. veganism is a first-world choice, of privileged individuals, who fail to recognize that not everyone can be vegan.

      • I don’t believe the 51% or 60% number for livestock either, but the point is that scientists have looked at the total greenhouse gases associated with different diets, and the vegan diet was best on that front. Argue with the author of the massive study reported in the June issue of Science.

        Also, there are people who actually study what initiated deforestation, and around 80% of the deforestation of the Amazon was to grow crops for livestock or graze livestock. Raising cattle to eat just uses an insane amount of the available land on earth, and if people went vegan or nearly vegan, that land could go back to being forests.

        A vegan diet with reasonable caloric intake requires about 1/6th the land of a omnivorous diet with reasonable caloric intake. In terms of land use, eating animals is just an incredibly inefficient way to get calories or protein or micronutrients.

        • wow, you just managed to ignore almost every valid point i made, and then restate the same myths with which you started. once more, going vegan isn’t the magic bullet you believe it to be. it’s not better for land use. in fact, recent studies have shown that a diet low in meat, but neither vegetarian nor vegan was better overall for greenhouse gases and land use. much of the land used for meat animals is suitable neither for crops nor habitation. many of the crops grown for animal fodder are perennial, and their growth is more efficient than typical feed crops, such as corn or soy. much of the forest cleared and seeded with animals is not for the animals, the animals are only there to show the land is being used…to claim it. stop repeating the same tired myths. reduction in meat consumption will be necessary to help mitigate the effects of AGW, but veganism and vegetarianism are greatly overrated in their contributions to reduction in greenhouse gases. if you really want to help, have one fewer kid. that will far outstrip the benefits of forgoing a car or going vegan.

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