An Open Letter to the WHO—Industrial Animal Farming Must End

“Unprecedented and rising levels of industrial animal farming are undermining the highest attainable standard of health that is WHO’s mandate”

Every year more than 55 billion land animals are raised and killed for food around the world. Most are reared in industrial factory farms in circumstances that harm human health and the environment in significant ways.

Worldwide livestock production is expected to more than double between 2001 and 2050, an increase that will undermine the World Health Organisation’s (WHO) aim of achieving the highest standards of global health.

Next month, as a new Director General takes over the WHO leadership, an open letter will be released calling for a reduction in factory farming and a shift towards more sustainable agricultural practices.

The letter focuses on factory farming’s contribution to three pressing global health challenges: antibiotic resistance, climate change, and chronic non-communicable diseases. Here are the letter’s key points.

Antibiotic resistance

Factory farming is highly intensive with large farms hosting tens of thousands of animals. Infection is constant problem and most farms use large quantities of antibiotics to control it. In the United States 80% of all antibiotics used are given to livestock.

The WHO estimates that between 2010 and 2030, antibiotic use in the livestock industry will increase by 70% worldwide, driven primarily by growth in industrial farming practices in low- and middle-income countries.

The use of antibiotics in livestock farming has been identified as an important contributor to antibiotics resistance. If antibiotics lose their effectiveness we will no longer be able to treat infections. This could lead to millions of unnecessary lives lost.

Already 700,000 people die from antimicrobial-resistant diseases each year around the word—23,000 of them in the United States—a figure that will continue to rise in the coming years unless we take urgent action.

Climate change and the environment

Livestock farming, particularly industrial factory farming, has a huge environmental footprint. It contributes to land and water degeneration, biodiversity loss, acid rain, coral reef degeneration and extensive deforestation, but also has a potent effect on climate change: nearly one fifth of all human produced greenhouse gas emissions emanate from the livestock sector. This is more than the emissions from cars, planes, ships, trains and all other forms of transport combined.

Climate change has been described as the greatest threat to human health and wellbeing of the 21st Century. Its impact will be felt through the increased incidence of severe weather events – tropical storms, floods, droughts and heatwaves—as well as the extended reach of infectious diseases such as malaria and Zika virus. Studies show that climate change is already harming us right now. By 2030 it is expected to cause upwards from 250,000 deaths each year.

Reducing livestock consumption is essential if we are to stay within 2C of warming, the agreed threshold for dangerous climate change. Without drastic reforms agriculture will account for half the world’s carbon budget necessary to remain under 2C by 2050.

Obesity and non-communicable diseases

Obesity and other non-communicable diseases are now the major cause of premature morbidity and mortality worldwide. Meat consumption, particularly of red and processed meat, is a significant contributor to this disease burden, increasing the risk for heart disease, obesity, diabetes, and various cancers—the WHO has classified processed meat as carcinogenic and red meat as probably carcinogenic.

Most people living in high income countries eat too much meat—on average 200-250g per person per day—much more than the 80-90g recommended by the United Nations. Reducing meat consumption in line with UN recommendations could offer substantial health benefits worldwide. By one estimate, we could save up to eight million lives every year by 2050 if we switch to a predominantly plant-based diet.

Open letter on factory farming

“The harms caused by large-scale, industrial animal farming are global in nature and felt beyond those who consume meat and dairy. Climate change does not recognize borders and neither do drug-resistant infectious diseases.”

The effects of factory farming represent a large and growing contribution to the global disease burden. In the face of these health challenges, reducing production and minimising its harm will be essential to securing the future of global health.

The open letter, initiated by Scott Weathers and Sophie Hermanns, will be delivered to the newly nominated WHO Director General next month. It has garnered signatures from Bill McKibben, Mark Bittman, Marion Nestle, Peter Singer, Noam Chomsky, and others, and is a call for action on factory farming:

  • We call on academics and researchers to apply their energy to document and publicize the harms of industrial animal farming to human, animal, and planetary health.
  • We call on all candidates for the WHO-Director General position to publicly acknowledge the harm that industrial animal farming inflicts on global health. The next Director General should take necessary steps to limit the expansion of industrial animal farming and encourage dietary recommendations that reduce meat consumption.
  • Finally, we call on the next WHO-Director General to provide global leadership to support the developing world in finding sustainable alternatives to the rapid growth of industrial animal farming and help shift us toward farming methods that protect public health and the environment.

The WHO has already made significant progress in tackling global public health challenges such as infectious disease, motor vehicle safety, and tobacco and sugar consumption. It is time for it to step up action on factory farming—the threats are too great to ignore.


Francis Vergunst is a postdoctoral researcher in developmental public health at University of Montreal.

Patrick Birkl is a PhD student in animal behavior and welfare at University of Guelph.

Read the Open Letter here.


  1. The evidence that meat consumption is excessive and unhealthy and that the reason is that there is something specifically unhealthy about meat is fairly bad. Excess calorie consumption and sugar/carbs are more likely contenders for diet-based health problems in the developed world.

    I am all in favor of reducing factory farming but I worry that its advocates want every fact in the universe to align with their desire to reduce animal suffering; it could turn out that reducing animal suffering is ethically preferable even if meat consumption is healthy.

    • Peter Bertel says

      just type “meat consumption obesity” in google scholar. You´ll find plenty of articles showing a variety of ways in which excessive meat consumption can compromise health. It is not only about animal cruelty. It is, as this letter clearly points out, also about human health.

      • Hi Peter. I’ve already read several of those articles. I do not think the evidence for the alleged badness of meat is very convincing. Excess calories, carbs, and sugar in particular seem like more plausible candidates for problems with obesity, and to the extent that we cut those, more of our diet will consist of protein/fat. Meat can be a fantastic source of both. If the problem, as some studies suggest, is caloric density, there are still questions about relative satiation based on type of food and it still isn’t a good argument against poultry, fish, and lean meat.

      • MOS says

        Excessive consumption of “factory farm” meat IS a major source of bad fat, excessive carbs and sugars. Select, Choice and Prime is nothing more than a word-smith of fat content. Some fat, more fat and a lot of fat. All produced quickly over a six month period by regulating the amount of sugar animals are fed prior to slaughter. Google “skittle accident Wisconsin” (spelled right ;-0). Bubble gum, week old pastry, rejected candy corn etc. Then look into high fructose corn syrup or, SUGAR. Its in tooth paste, shampoos, moisturizers, lip balm, sunscreen. Like Micheal Pollan stated in Omnivore’s Dilemma, “we are nothing but a walking potato chip. Switch to Grass Fed / Grass Finished beef and you have the right balance of Omegas and CLA – a great building block for health. Also read The Vegetarian Myth and The Story of the Human Body. We’ll get there by our pocket books!! Research, shop right, be healthy.

        • Factory farmed meat is a major source of carbs and sugar? I am a bit perplexed. Are you saying that when I eat beef, that it is full of carbs and sugar, because the cows are fed skittles?

          I’m not sure why you bring up shampoo and tooth paste. I am questioning claims about the health consequences of eating meat. I’m not discussing sugar in other products. I’m also not sure why you bring up grass fed beef.

  2. bowneps says

    I don’t disagree with the content but with the strategy. Why are people so in love with open letters? My opinion of them is entirely negative, but I’m willing to be convinced otherwise.

  3. There are compelling reasons to abandon factory farming that are entirely independent of concerns about animal suffering. This article is a good summary of some of those reasons.

  4. DJA says

    While not trying to specifically disagree with the article, what I think is important is that we are quite clear how ‘factory farming’ is defined.
    The article refers to some practices as characteristics of ‘factory farming’, but does,for instance, giving antibiotics to animals make them factory farmed? We have a problem in the world of antibiotic resistance is that because human beings have been factory farmed?
    Farming of any sort is not natural, but it has been done by human beings for several thousands of years now. So at what stage of development/modification does ordinary farming become factory farming? Before the days of sterilization and pasteurization in order to deliver the milk as quickly and as fresh as possible cows were mainly kept during the time of their lactation in small buildings virtually in the middle of cities chained up by their necks for the rest of their profitable lives.was that ‘factory farming’.
    So rather than using the ill defined term ‘factory farming’ I suggest it would be better for WHO to simply list (with reasons) what it regards as specifically undesirable farming practices.

    • Caroline Rowley says

      Did you actually read the letter? Factory farming is intensive farming with large numbers of animals (normally thousands.) They are given antibiotics because they are living in cramped, filthy conditions and susceptible to disease. Humans eat the animals that have been pumped full of antibiotics and build up a resistance to them. Perhaps you should do a bit of research – there’s a thing called google…..

      • Ricardo says

        Caroline, snarky response to DJA. Your beef (pardon the pun) with “factory farming”, is the animals are “pumped full of antibiotics”. DJA acknowledged that in his response. His (and mine) concern is that “factory farming” is not descriptive of the issue. A list of practices they don’t think are healthy is more productive.

        • Caroline Rowley says

          DJA is unclear of what factory farming is even though the letter describes it (that’s why I asked if he read it) and he is implying it’s been around forever, which it hasn’t. He also made some nonsense comment about humans being factory farmed so I explained in simple terms what factory farming is and the significance of factory farming to the antibiotic crisis. The letter is to the WHO, not from the WHO so I don’t see the relevance of his last comment and I suggested he do a bit of research to find out more about factory farming – fair comment I thought. The letter explains quite clearly what the issues with factory farming are – let me explain. Factory farming is intensive farming ie thousands of animals squashed in a shed. Aside from the cruelty aspect their are health and environmental issues.
          1. Antibiotic resistance – factory farmed animals are fed huge quantities of antibiotics because there are thousands of animals living in cramped, dirty conditions where disease can easily spread. The antibiotics pass through to the meat and get consumed by humans who are becoming resistant to them and will die.
          2. Climate Change and Environment – factory farmed animals are fed huge quantities of grain, grown intensively with large amounts of chemical pesticides and fertilisers, rather than being allowed to graze outside in fields. These lands release large amounts of CO2 into the atmosphere, causing climate change. The pesticides and fertilisers pollute waterways and kill bees etc, waterways are also polluted by large amounts of excrement from the farms and finally it takes a vast amount of water to grow all the grain and water the millions of animals factory farmed world wide.
          3. Obesity and non-communicable diseases – eating cheap, processed, factory farmed meat laced with antibiotics and growth hormones, fed on chemically grown grain, is leading to obesity, heart disease, cancers etc.
          If the animals were grass fed the above issues would not apply. They would not need antibiotics, they would not be given growth hormones or chemically grown grain. There would not be huge amounts of waste to dispose of. Grazing lands actually absorb CO2. The animals would have a better life and their meat would be healthier. We would eat less meat because it would be more expensive and supply would be reduced. I hope that explains what practices in factory farming are unhealthy.

          • Caroline,

            You are partially wrong about one thing (twice). Antibiotics aren’t just fed to animals to prevent disease. If that was the case, they’d be fed a lot less of them then they are.

            Antibiotics are fed to perfectly healthy animals (even those not being brought up in cramped conditions; even by small-time farmers in China who raise just a few pigs at a time; etc.) in order to promote growth. Inject a cow with a low of antibiotics, and you’ll get a bigger cow. This of course, is even WORSE than the reason you describe. However it also why DJA is correct – bad farming practices must be enumerated precisely, otherwise people will get the idea that all problems will be solved if we just let the cows roam free (while still pumping them full of antibiotics and food they shouldn’t be eating).

  5. mikeb says

    There are over 7 billions hominids on the planet. They like to eat meat. An industrial-size population takes industrial methods to feed. Get over it.

    • Linda Stones says

      There’s nothing wrong with saying that or suggesting that people eat grass fed or organic meat. And, also, factory farming is cruel to animals. It’s not natural. And, there’s nothing wrong with having some compassion for these creatures.

  6. CLR says

    And when the last scrap of fertile soil on Earth has been depleted to grow the last batch of crops to feed the last cow to produce the last juicy steaks and burgers, maybe we can simply get over that too

  7. Ward says

    People are hooked on meat just like any other drug. You can’t convince a drug addict to stop using no matter how many fact you give them. Addiction is the same with meat. People will deny that they are addicted to their last breath and like any addict they don’t care how bad it is for the environment the animals or their own health. They only care about that next fix but like all addicts they pay the price. This is why when people get on social media begging for sympathy because they are dying of cancer, heart disease or diabetes and they eat meat and dairy all I can say is you reap what you sow. Have another burger disbelievers.

  8. “more sustainable”

    Aaand this article is where Quillette has jumped the shark. I’m surprised the word “justice” didn’t show up here somewhere – “farming justice”, perhaps.

  9. Peter Bertel says

    You are right; lean meat, poultry and fish in “modest amounts” will not cause health issues. I guess even plant-based-diet advocates would sign that statement. But there are two problems: one is the question of “how much is too much”? I could give 1 Million people a cigarette a day for 10 years and most likely none of them would develop diseases related to smoking- which does not mean that smoking is perfectly healthy. The other issue is that many diseases, such as obesity or diabetes are multi-factorial. So while excessive meat consumption is certainly not the sole cause for many diseases, it can play an important role. Most nutrition people I talk to are most concerned with the fact that for many people meat replaces a balanced diet. So it’s not the fact that they eat too much of one thing, but it’s that they eat too little of other things. It took us a an embarrassingly long time to admit that smoking can cause health issues, that leaded fuel can cause health issues etc.. If we would wait until all molecular pathways of cancer development and how they are impacted by what chemicals in cigarettes, we would still have to say: Smoking does not cause cancer. Sometimes we have to go with correlations before we dissect the causation in detail. Same goes with excessive meat consumption.

  10. chris says

    This is definitely a blot on Quillette’s otherwise excellent standards. Poorly argued activism at best.

  11. Santoculto says

    Other great problem is to think ”all animals of certain species of certain chosen groups are the same, have the same personality, temperament” : to be used as food. A unusual way to solve the possible or inevitable necessity of ”meat” human consume, specially in some places where the climate don’t favor abundance of fruits and vegetables would be exactly stop to generalize ”chosen animals [and ”animals” in general] ” as if they were all the same and start to select those who are less senscient or more ”psychopathic-leaning” to be indeed used as food and select those who are friend-leaning only to reduced creation and maybe by a partial pan-evolutionary convergence among humans and some other living beings.

Comments are closed.