How Much Do Cattle Really Contribute to Greenhouse Gases/Climate Change?

Recently I’ve been pondering the effects of what humans eat on our planet. With a few exceptions, I’ve steered clear of politically charged issues on The Skeptical Cardiologist and tried to focus on issues relevant to cardiovascular health, especially ones espoused by mainstream guidelines which lack a solid scientific basis (e.g. dairy fat is bad for you.)

In the diet wars, I am a neutral observer, although I can be a keto-friendly cardiologist I also advocate prioritizing whole fruit and vegetable intake to my patients.

I’ve written extensively on the lack of science underlying vegan diet claims to prevent or reverse coronary heart disease but also recognize the pseudoscience that purveyors of the carnivore/bullet-proof/paleo diets on the far end of the meat-centric spectrum spew. For an excellent discussion on the nuttiness on both ends of the dietary tribal wars I recommend episode 401 of the Sigma Nutrition podcasts which inducts Dr. Michael Greger, Eric Berg DC, and Paul Saladino, aka the Carnivore MD into their Quack Asylum

When it comes to fat consumption the scientific evidence does not tell us we should be eating less of the saturated fat that comes from dairy products. In addition, I’m not convinced by vegan arguments of cruelty to cows because I’ve seen how cows can be treated like members of the family on well-run dairy farms.

One argument that has captured my attention is that by switching from dairy and meat consumption to a completely plant-based diet we can reduce greenhouse gas emissions.

The Dogma on Climate Change: Eating Meat is Killing the Planet

Professor Google answers my titular question with this factoid from an article on Inside Climate News, versions of which pop up in most articles on diet and climate change and which most journalists in the climate change arena accept unquestioningly:

Emissions from livestock account for about 14.5 percent of total greenhouse gas emissions, globally, and roughly two thirds of those emissions come from cattle — mostly from methane burped by cows, growing feed and clearing land for grazing and feed crops.

Even more depressing for we omnivores, Inside Climate News also tells us that “Air Pollution From Raising Livestock Accounts for Most of the 16,000 US Deaths Each Year Tied to Food Production, Study Finds”

Substituting poultry for meat could save 6,500 lives and if everyone converted to veganism even more lives would be saved according to this

The Canadian website Let’s Talk Science, aimed at promoting STEM learning in youths, ends a piece on cows, methane and climate change by telling kids that eating less meat will mitigate climate change.

But as you have just learned, methane gas emissions from livestock are a huge problem. So driving less may not be the most important thing we can do to help mitigate climate change. Many experts now believe that eating less meat would actually have a bigger impact.

From Let’s Talk Science: How burps and farts of methane are produced

Marion Nestle’ Piles on the Anti-Beef Wagon Then Reconsiders

The beef industry thinks the 14.5% number is wrong and has attempted to counter the prevailing wisdom that beef consumption is nonsustainable. Marion Nestle, at Food Politics wrote a post critical of a beef industry ad that claimed that American beef contributes only 2% of greenhouse gases. 

From Food Politics courtesy of Lisa Young, Ph.D

Two of her readers objected to her use of the widely quoted figure of 14.5% and argued for a correction.

The first was Stephen Zwick, who writes a blog that advocates “regenetarianism” and is independent of industry interests. The notes he sent Nestle’ are summarized in a subsequent blog post and include these points

-The 14.5% figure comes from a study that included land-use change, “specifically in Brazil at peak deforestation rates from 1998 to 2004,” and just for OECD countries.

-In North America, deforestation isn’t a large issue. The 2014 UN Climate Change Conference numbers from countries where land change is not a big factor total 8.1% for all agriculture. Of that, only a quarter is from enteric fermentation (cattle methane burps). Adding in manure management, brings it to about 40% of 8.1% or a bit over 3%.

-These global or regional numbers also don’t account for soil sinks or tropospheric sinks, a topic he covers in these 3 blog posts,

Zwick concludes

“Ruminants and other sources of biogenic methane aren’t the problem. Thermogenic sources (fracked gas, coal bed gas and other fossil fuels) of GHG’s are. Enteric methane is a distraction. Poor land management destroying soil sinks and reducing photosynthesis via desertification, deforestation and ocean acidification are also a huge problem. And yes, cattle and palm oil are part of the problem in tropical regions as I noted in this more recent blog post, The Deforestation Process... Cattle is a very conspicuous driver, though it’s not really the primary driver. Human greed is.”

Elsewhere Zwick has written an excellent piece entitled “Life and Death from the soil food web on up” which begins with this quote:

“Part of living is killing. I don’t care if you eat vegan or you eat meat, you are responsible for death. I would argue that if you’re vegan, you are responsible for way more death than if you eat a healthy, regenerative diet with grass-fed meat. As a regenerative rancher, it’s part of our responsibility to give more life than we take. We understand—because we understand nature—that every part of eating is killing, no matter what it is. A plant doesn’t have a heart or lungs, you’re right. But that crop field growing crops was once life to a huge diversity of plants, and animals, and birds, that are now gone. You are responsible for that patch of cropland killing that habitat, and killing all of those animals that could be living there—living there alongside your grass-fed steer, or living alongside your diversified agriculture crop.”       

Doniga Markegard, author of Dawn Again: Tracking the Wisdom of the Wild

and is followed by this intriguing paragraph

“meats versus plants is a false dichotomy. Doing the least harm, causing the least amount of suffering and creating the most diversity is more a matter of balance than absolutism. So for any type of food, whether from plants, animals or fungi, there are a wide array of ways to grow, catch or raise that food ranging from very bad to very good. This is especially true in regards to overall impacts on ecosystems and other sentient beings. So the HOW and appropriateness of WHERE any particular food is grown, raised or caught often matters as much or more than the WHAT that’s raised, grown or caught.”

Does Beef do More Damage Than Transportation?

Frank M. Mitloehner, a Ph.D. Professor of Animal Science at UC Davis has studied the ways in which animal agriculture affects air quality and climate change for 20 years and convincingly argues that meat’s bad rap on GHG is undeserved .

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 percent 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. .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 when they analyzed transportation.

even if Americans eliminated all animal protein from their diets, they would reduce U.S. greenhouse gas emissions by only 2.6 percent. According to our research at the University of California, Davis, if the practice of Meatless Monday were to be adopted by all Americans, we’d see a reduction of only 0.5 percent.

Defending Beef

After researching this topic, I don’t think we should be teaching kids that eating less meat would have a bigger impact on climate change than driving less. I don’t think the science is settled on whether switching from dairy and meat consumption to a completely plant-based diet will significantly reduce greenhouse gas emissions.

While pondering this topic I listened to a podcast that featured Nicolette Hahn Niman, a former vegetarian and environmental activist who married a cattle rancher. Before writing the book, Defending Beef she was the senior attorney for the environmental organization Waterkeeper Alliance, where she was in charge of the organization’s campaign to reform the concentrated livestock and poultry industry, and before that an attorney for National Wildlife Federation.

I have purchased her book Defending Beef: The Ecological and Nutritional Case for Meat, which argues for the benefits of regenerative beef production. She believes and I agree that

the problem with our food system is industrialization, and [fake meat is] an industrial food. It’s produced on an agricultural level, industrially, almost universally, and it’s a highly processed food before it gets to your plate. 

Animals are essential in her mind as they

add an element that cannot be replaced with chemical amendments to the soil. That’s been done for decades and didn’t work. What regenerative agriculture is all about is understanding relationships and connected connections between living things, and trying to foster life. And to me, that is absolutely the direction that farming has to go and whether it’s on a small scale or large scale.

I’ll finish reading her book and give a detailed review in a subsequent post.

In the meantime, although I’m a huge advocate of minimally processed vegetables, nuts, pulses and fruit, I see no compelling reason from an environmental perspective to eliminate beef from my diet or from the diet of my patients who have documented coronary artery disease.

Antifartinogenically Yours,



16 thoughts on “How Much Do Cattle Really Contribute to Greenhouse Gases/Climate Change?”

  1. The problem you have there is that you fail to understand that all of the livestock methane is cyclical. It doesn’t actually add significantly to warming impact. Emissions is an abstract term which is ultimately no indicator of warming impact. Thankfully we now have GWP* rather than the not-fit-for-purpose GWP100 for assessing methane. Prof Myles Allen and his team who brought GWP* methodolgy to the world has repeatedly been quoted as saying that if all of the world’s cattle and sheep were removed tomorrow then the best that could be hoped for would be a reduction in warming of less than 0.1 degC. And that is ignoring all of the negative impacts that would result because of the unintended consequences of more carbon being emitted into the atmosphere as a result of loss of ruminants, let alone increase in soil erosion, loss of biodiversity etc. The climate system is well used to dealing with large numbers of ruminants and has done so for millions of years. However it is NOT used to dealing with massive extraction and burning of fossil fuels. Only a fool would actually believe the creative accountancy that points at ruminants causing climate change.

    • If we as humans want to reduce greenhouse gases we need to reestablish prairie lands, the roots of those type of plants can sequester CO2 because they grow 6 feet deep or more. Corporate farms have stripped prairie lands and have contributed to the greenhouse effect more than cattle.

  2. Have you watched the documentary “Kiss the Ground”? The way out of climate change is to go back to organic farming and that takes cattle/cows. We can stop emitting green house gases but without their removal it’s all for not. Organic farming sequesters the most CO2 by growing deep rooted plants, and again that takes manure from cattle.

  3. I found this blog quite interesting. Definitely food for thought. I am a vegetarian for many years, but I too would like to know if the dairy industry is also the veal industry. I was a young teenager when I found out what veal and lamb chops and never ate them again. I had a friend in college ( Grinnell, Iowa) whose family ran a poultry farm. He described to me in graphic detail how the chickens were slaughtered. Made me ill and then never ate chicken again. Do we need to talk about those horrific hog farms in Iowa and MO. It’s beyond cruel what is done to the pigs who are extremely intelligent species. You can probably see where this lead up to and becoming a vegetarian. The cows producing 14.5%, of greenhouse gases always seemed to me a bit questionable so I welcome the additional thoughts.

  4. I reject the hypothesis of emissions (whatever these are) as instrumental to warming the planet – even more the hubris that man can affect planetary temperatures – even more that the planetary temperature today should actually be 1.5 degrees colder and the existential threat is averted. Reality is in short supply with this catastrophic warming cabal. Good stewardship of our land and compassionate husbandry of those under our dominion would go a long, long way. Now will you please pass over more of that oh so delicious prime rib !

  5. This was interesting. I am open to the ideas regarding pollution.

    But it doesn’t change my mind regarding the ethics.

    You said that you were convinced after visiting a small, well-run dairy farm.

    But isn’t that a bit like saying you visited a humane prison in Norway so we don’t have to worry about prison abuse in the United States?

    It seems more like the exception.

    And I am not sure about the comparison to the animals being like family. I won’t use the graphic term, but dairy cows are continually impregnated. Obviously that is not consensual. There is an illustrative term in the dairy industry for this.

    And the male offspring are slaughtered. Even if not at the dairy farm, that is where they will be headed. The dairy industry is the veal industry. They are one and the same. They are separated from each other, and the cows are known to be distressed over this.

    Not exactly like how you treat members of the family.

    I hadn’t considered the displacement of animal and wildlife for crop growing. But from what I understand, cows need far more resources and are more inefficient at using them than plants.

    • Marcus,
      I agree that none of what I wrote should influence one’s ethical approach to animal treatment.
      I will have to check with Trader’s Point Creamery to see if, as you say, “the dairy industry is the veal industry”.
      Dr P

  6. Dr. P

    The issue with livestock methane as it relates to global warming is far more complex than comparing bovine methane to fossil fuel pollution. An extraordinary and final espisode of naturalist David Attenborough’s BBC series “A Life on Our Planet” is a great start to understand the larger problem. This beautiful ‘witness statement’ by this world renowned naturalist reviewing what he has learned in his 93 years of life can be seen on Netflix, and other sources. See:

    The United Nations now estimates about 690 million people went hungry in 2019. The UN estimates agriculture, including forestry, fisheries and livestock production, generate around a fifth of the world’s greenhouse gas emissions. This must be reduced by 2030 to achieve the goal of limiting global warming to 2°C. The Intergovernmental Panel on Climate Change (IPCC) is the United Nations outlines the many factors linking climate change to food here:

    The UN News concluded 11/7/2021: “The UN World Food Programme (WFP) warned on Monday that the number of people teetering on the edge of famine in 43 countries, has risen to 45 million – up by three million this year – as acute hunger spikes around the world.”

    Global Warming / Climate Change / Ecological species collapse / economic disaparity and poverty, are all linked in profound interdependent ways. We need to re think the whole of what we eat, what we strip from our globe, and above all: how we use land, water, air and sea.

    • Time Magazine just published (12/2/2021) an article that concluded:

      “The one billion cows used in the global meat and dairy industries, combined with other animals raised for livestock, are responsible for releasing the methane equivalent of some 3.1 gigatons of carbon dioxide into the atmosphere every year—accounting for some 44% of global anthropogenic methane. If the global livestock industry were its own country, it would be the world’s third-biggest greenhouse gas emitter, falling between U.S. and India when it comes to total greenhouse gas emissions……”

  7. I totally agree with the above statement in your post about a crop field was once home to a great diversity of plants, animals, etc.
    We once tried to make a serious effort at growing vegetables—it was clear we were in competition with the birds, squirrels and rabbits for the resources in our yard.

  8. Your post, factual and unsensationalized, plus rational Jeff Robbins op-ed on Biden Administration in Bartlesville Examiner Enterprise (!!!) Thursday gave me something to read while visiting B’ville that didn’t make me roll my eyes. Thank you!

    • Jeanne,
      So glad to hear! My sister visited Bville last week and had some Murphy’s beef and a close encounter with Bison at Woolaroc.
      Dr P

      • Hah! My husband and son disgusted by my insistence on eating at Murphy’s on visits home. They vividly imagined a giant barrel of brown gravy lurking malevolently outside. Have a pic of gunshot-perforated Murphy’s steer sign in my kitchen hallway. Love it.

  9. As a retired, small scale beef cattle raiser for many years, I applaud your sensible information disseminated here. I try to keep a good variety of food types in my diet and beef is part of it. Thank you!


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