Meat: why giving it up won’t save the planet – or your health

By Marika Sboros

Animal rights activists (and the vegans who front them) want you to believe that giving up meat will save the planet from climate change. If only it were that simple.

They also say a meat-free diet is healthier for you. Some call for a tax on meat to reduce consumption.

Prof Frank Mitloehner

Dr Frank Mitloehner is professor of Animal Science and a specialist in Air Quality Extension at the University of California, Davis. He looks at the key claim underlying the argument for eating less meat: that global meat production generates more greenhouse gases than the entire transportation sector.

In the article below, Mitloehner explains why this claim is “demonstrably wrong”. It has become a “bell” that scientists are struggling to “unring”, he says. Its persistence has led to “false assumptions about the linkage between meat and climate change”. And your health.

Mitloehner’s focus is the general study of and support for conventional, mainstream agriculture and making it more efficient.

US lawyer and cattle rancher Nicolette Hahn Niman has a very different perspective. Before you dismiss what Hahn Niman says, she is that rare breed: a cattle rancher and a vegetarian for 30 years.
However, she is not a vegetarian because she finds health or ecological arguments against meat convincing.

Is meat the optimal human diet?

On the contrary. Hahn Niman has focused on what diet is best for planetary and human health for the past 18 years. The more she has learned, the more convinced she is that “ecologically optimal food systems include animals and an optimal human diet includes meat”. To that end, she is considering adding bone broth to her diet.

Click here to read: Mikhaila Peterson:  poster girl for carnivore living 


Her work, in contrast to Mitloehner’s, is about building a better, quite different agricultural model. It is one that prioritises ecological health, animal welfare, and producing nutrient-rich foods.

Hahn Niman

In other words, she does not believe that we need to stay with status quo models. In fact, she does not even believe that we should. Hahn Niman has documented her views in a remarkable book: Defending Beef: The Case for Sustainable Meat Production.

“At a minimum, we must get grazing animals back on grass,” she says. Thus, her focus is on the importance of grazing animals on pastures and rangelands. She also emphasises the manifold ecological benefits that come from well-managed grazing.

Planting trees

In her book,  Niman goes through all this in detail. The short version is: The earth evolved for tens of millions of years with huge herds of grazing herbivores.
Our planet’s ecosystems starting with soil microorganisms – the foundation of all terrestrial ecosystems – evolved under those conditions.
The absence of those herds today is impairing the earth’s function. We actually need the domesticated grazing animals as a substitute for the ecological role of the disappeared wild herds.
“Planting trees on its own will never restore the earth’s desertified lands.” Hahn Niman says. will feature her in a lengthier interview. For now, here’s what Mitloehner has to say:

By Frank M. Mitloehner, University of California, Davis

As the scale and impacts of climate change become increasingly alarming, meat is a popular target for action. Advocates urge the public to eat less meat to save the environment. Some activists have called for taxing meat to reduce consumption of it.

A key claim underlying these arguments holds that globally, meat production generates more greenhouse gases than the entire transportation sector. However, this claim is demonstrably wrong, as I will show. Its persistence has led to false assumptions about the linkage between meat and climate change.

Setting  record straight on meat and greenhouse gases

Global livestock production (milk, eggs expressed in protein terms). FAO, CC BY-ND

My research focuses on ways in which animal agriculture affects air quality and climate change. In my view, there are many reasons for either choosing animal protein or opting for a vegetarian selection.

However, foregoing meat and meat products is not the environmental panacea many would have us believe. And if taken to an extreme, it also could have harmful nutritional consequences.

A healthy portion of meat’s bad rap centres on the assertion that livestock is the largest source of greenhouse gases worldwide.

For example, a 2009 analysis by the Washington, D.C.-based Worldwatch Institute asserted that 51% of global GHG emissions come from rearing and processing livestock.

Largest sources of greenhouse gas emissions

According to the US  Environmental Protection Agency, the largest sources of US GHG emissions in 2016 were electricity production (28% of total emissions), transportation (28%) and industry (22%). All of agriculture accounted for a total of 9%.

All of animal agriculture contributes less than half of this amount, representing 3.9% of total U.S. greenhouse gas emissions.

That’s very different from claiming livestock represents as much or more than transportation.

Why the misconception? In 2006, the United Nations Food and Agriculture Organization published a study titled Livestock’s Long Shadow, which received widespread international attention. It stated that livestock produced a staggering 18% of the world’s greenhouse gas emissions.

The agency drew a startling conclusion: Livestock was doing more to harm the climate than all modes of transportation combined.

Click here to read: Carnivore Queen: Hacker O’Hearn on magic of meat


This latter claim was wrong and has since been corrected by Henning Steinfeld, the report’s senior author. The problem was that FAO analysts used a comprehensive life-cycle assessment to study the climate impact of livestock but a different method of analyzing transportation.

What the experts ignored

For livestock, they considered every factor associated with producing meat. This included emissions from fertilizer production, converting land from forests to pastures, growing feed, and direct emissions from animals (belching and manure) from birth to death.

Click here to read: Lifestyle medicine: front in Big Religion’s war on meat?


However, when they looked at transportation’s carbon footprint, they ignored impacts on the climate from manufacturing vehicle materials and parts, assembling vehicles and maintaining roads, bridges and airports. Instead, they only considered the exhaust emitted by finished cars, trucks, trains and planes.

As a result, the FAO’s comparison of greenhouse gas emissions from livestock to those from transportation was greatly distorted.

Researchers have identified multiple options for reducing greenhouse gas emissions from the livestock sector. Red bars represent the potential range for each practice. Herrero et al, 2016, via Penn State University, CC BY-NC-SA

I pointed out this flaw during a speech to fellow scientists in San Francisco on March 22, 2010. It led to a flood of media coverage. To its credit, the FAO immediately owned up to its error. Unfortunately, the agency’s initial claim that livestock was responsible for the lion’s share of world greenhouse gas emissions had already received wide coverage.

‘Unringing’ the bell

To this day, we struggle to “unring” the bell.

In its most recent assessment report, the FAO estimated that livestock produces 14.5% of global greenhouse gas emissions from human activities. There is no comparable full life-cycle assessment for transportation. However, as Steinfeld has pointed out, direct emissions from transportation versus livestock can be compared. These amount to 14% versus 5%, respectively.

Many people continue to think avoiding meat as infrequently as once a week will make a significant difference to the climate. But according to one recent study, even if Americans eliminated all animal protein from their diets, they would reduce US  greenhouse gas emissions by only 2.6% According to our research at the University of California, Davis, if all Americans adopted the practice of Meatless Monday, we’d see a reduction of only 0.5%.

Moreover, technological, genetic and management changes in US agriculture over the past 70 years have made livestock production more efficient and less greenhouse gas-intensive. According to the FAO’s statistical database, total direct greenhouse gas emissions from US livestock have declined 11.3% since 1961. Production of livestock meat has more than doubled.

Where opportunities lie

Demand for meat is rising in developing and emerging economies, with the Middle East, North Africa and Southeast Asia leading the way. But per capita meat consumption in these regions still lags behind that of developed countries. In 2015, average annual per capita meat consumption in developed countries was 92 kilograms. That’s compared to 24 kilograms in the Middle East and North Africa and 18 kilograms in Southeast Asia.

Still, given projected population growth in the developing world, there will certainly be an opportunity for countries such as the US to bring their sustainable livestock rearing practices to the table.

The value of animal agriculture

Removing animals from US agriculture would lower national greenhouse gas emissions to a small degree. But it would also make it harder to meet nutritional requirements. Many critics of animal agriculture are quick to point out that if farmers raised only plants, they could produce more pounds of food and more calories per person. But humans also need many essential micro- and macronutrients for good health.

It’s hard to make a compelling argument that the US has a calorie deficit, given its high national rates of adult and child obesity. Moreover, not all plant parts are edible or desirable. Raising livestock is a way to add nutritional and economic value to plant agriculture.

As one example, the energy in plants that livestock consume is most often contained in cellulose, which is indigestible for humans and many other mammals. But cows, sheep and other ruminant animals can break cellulose down and release the solar energy contained in this vast resource. According to the FAO, as much as 70% of all agricultural land globally is rangeland that can only be utilized as grazing land for ruminant livestock.

Challenges of feeding 9.8 billion people

The world population is currently projected to reach 9.8 billion people by 2050. Feeding this many people will raise immense challenges. Meat is more nutrient-dense per serving than vegetarian options. And ruminant animals largely thrive on feed that is not suitable for humans.

Raising livestock also offers much-needed income for small-scale farmers in developing nations. Worldwide, livestock provides a livelihood for 1 billion people.

Climate change demands urgent attention, and the livestock industry has a large overall environmental footprint that affects air, water and land. These, combined with a rapidly rising world population, give us plenty of compelling reasons to continue to work for greater efficiencies in animal agriculture.

I believe the place to start is with science-based facts.The Conversation



  1. I think most of the carbon the herbivores emit is carbon that was removed from the atmosphere by the plants they ingest. They may emit carbon, but also sequester carbon (pastured grazing – not confined feedlot model) on a net basis. The transportation emissions are entirely a new introduction of (fossil) carbon to the atmosphere. If we are considering emissions without considering net new carbon added to the atmosphere, then the comparison is bogus.

  2. From a purely scientific perspective, when assessing the negative impact of animal agriculture on the environment (‘the planet’), one would also have to take into account water use, deforestation and ocean dead zones, not just GHGs. The facts will need to speak for themselves, if they can overcome vested interests and confirmation bias.

  3. Very good article Marika. I would like to add an important factor that is so often excluded–I suppose because no one has studied it properly. I think that, with all said and done, one of the main reasons why cattle emit as much gas as they do–and as you pointed out, studies are very confused how to even calculate how much they actually emit–is because of what they are fed and under what cramped conditions.

    Today, on most regular commercial ranches, cattle are fed corn and soy. Neither is their natural food source. This food change may be equivalent to feeding humans grass. How much gas would humans produce from eating grass while being cramped in a standing-room only environment day and night for life?

    Would that be a reasonable assessment of human gas-production as the portion affecting greenhouse gases? Because what we are doing to cattle is exactly that: feeding them the wrong food and expect them to have perfect gas-free digestion.

    I watched in a recent BBC news stories with disbelief that researchers are mixing now coconut oil in one case and sea weed into cattle feed to test if they would have less gas emission. Honestly? Sea weed and coconut oil for herbivores that are supposed to eat grass?

    I think scientists have great heads on their shoulders but often forget to use them.

    • Well actually seaweed may not be that unnatural, we have cows and sheep that graze on saltmarshes and beaches (and very tasty they are too!)

      But yes current agriculture feeding excess grains to cows and chickens can make them ill in a curiously similar way to humans – especially wheat, as I have been told by farmers. On the other hand they can graze lands which could never be used to grow crops.

      Really some of these urban vegans need to see the countryside for themselves. Many cows and sheep need little looking after and regenerate the soil and increase numbers of small mammals and other wildlife, whereas those fields of Holy Health Grains and margarine (rapeseed) require huge machines with huge consumption of diesel and huge inputs of chemicals. When the cows (not all) go indoors for the winter they are fed haylage and silage and produce manure which can then be spread on the arable land to improve the soil. Most of my meat comes almost from walking distance to a local slaughterhouse and meat packing plant owned by a local family and then on to local shops. No corporates there sucking profits out of the local economy, probably a big reason for the fightback by Big Grain and Big Vegetable Oil.

      Just look at what farmers are paid for their wheat, then look at the price of “healthy” cereals. The markup is huge, and of course while farmers are “paid” subsidies they only get to hold the money for a while and then pass it on to the food processors and supermarkets in the form of reduced prices for their crops.

      When I used to eat wheat I used to blow off like a carthorse. On low carb I seldom fart. The volume of vegan farts should be taken into account also.

      • Hey Chris, nice seeing you reading things I read not just what I write! 🙂

        You made we laugh about blowing off like a carthorse. So true! One of my “patients”, who was a vegan before she met me, told me that she had more bowel movements a day than she now (on carnivore at the moment) has in a week–and she is regular every day. So that ought to tell the story right there as well–more environmental toxic stuff that is not even considered.

        You are right about the seaweed. Cows could eat that but apparently most spit it out according to this researcher. I suppose it takes a special cow to eat fishy stuff. I totally agree with you on urban vegans having to visit a land that is alive and compare that with land where annuals are grown and which destroy the soil and all creatures that live in it. It should be taught in schools–I am not going to hold my breath on that.

  4. One can only wonder about the past ecological “damage” done to air & grasslands of North America by the American Bison.
    Before the Pale-faces displaced and destroyed those massive free-ranging herds, population estimates were in excess (1800’s) of 55 Million.
    Global Warming did not appear to be an issue, despite all that flatulence !

    • Enteric methane isn’t “flatulence”…No, enteric methane is more akin to burps. Cattle are foregut fermentors. Hindgut fermentors like humans have more flatulence problems. Methane is emitted from lots of sources like cockroaches, wetlands, shellfish, etc. Cattle tend to get the blame simply because they’re the easiest to inventory in bottom-up analysis. For a more detailed understanding of methane math and context, please read this entry I wrote on my blog: Thanks.

    • Thinking of those bison that roamed the land I’m standing on – grazing of grasslands by herbivores builds soil organic matter much faster than forests do, owing to the high efficiency of sedges and grasses. Prairie soils were many feet deep, all built since the last ice age owing to herbivore/grass symbiosis.

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