Does Animal Agriculture Cause Climate Change and Pandemics?

The global animal agriculture industry rears and slaughters billions of creatures each year to produce meat, dairy, eggs and other products, all for human consumption. As global demand for these animal-based foods continues to rise well past sustainable levels, animal farming around the world has shifted to become more intensive and industrialized to keep up with demand.

In wealthy nations, as well as increasingly in lower-income countries, the animal agriculture industry is dominated by large-scale industrial farms housing thousands of animals in a system marked by overcrowded and unsanitary confinement. 

The purpose of intensive animal farming is to produce meat and dairy as efficiently and quickly as possible, raking in billions of dollars for the multinational corporations that control the supply chains while these systems continue to put the health of humans, animals and the environment at risk.

What Is Animal Agriculture?

The term “animal agriculture” means animal farming. It refers to the breeding, raising and slaughter of animals for products intended for human use, as well as crops used to feed farmed animals.

While animal agriculture or “animal husbandry” may still conjure up images of idyllic pastures and small family farms in the minds of some consumers, the reality is that animal farming has become an increasingly intensive industry, synonymous with factory farming in many parts of the world. 

Does Agriculture Include Animals?

The term “agriculture” covers growing plants for food and raising farmed animals, known to the industry as “livestock.” Farmed animals can include pigs, cattle, turkeys, sheep, goats, geese, ducks and chickens — the most commonly farmed land animal. More than 8 billion chickens are slaughtered annually in the U.S. alone, and 72 billion were slaughtered globally in 2019. For comparison around 300 million cattle and 1.5 billion pigs are killed for food globally each year.

Agriculture also includes fish and other aquatic animals, farmed in the estimated trillions. More of the global seafood supply now comes from aquaculture — the farming of aquatic species — than from wild fishing operations.

What Is the Definition of Animal Agriculture?

While animal agriculture commonly refers to the raising of farmed animals, there are standard definitions offered by the U.S. Environmental Protection Agency (EPA) that further distinguish between farming operations and which different regulations may apply.

The EPA defines Animal Feeding Operations as “agricultural operations where animals are kept and raised in confined situations,” but this does not include farmed fish. AFOs typically operate on “a small land area,” where animals are “stabled or confined” for at least 45 days in a year and are given food rather than being allowed to graze in pastures.

Some AFOs operate on a larger scale, confining more animals. These may be defined as Concentrated Animal Feeding Operations (CAFOs), commonly called factory farms.

What Is Animal Agriculture Called?

Livestock farming goes by different names depending on the scale of farming and other aspects of the ways in which the animals are raised. Generally, farming animals on a large scale in industrial conditions is known as intensive animal agriculture or factory farming.

Intensive Animal Agriculture

While the term “intensive animal agriculture” may sound extreme — and the conditions in which this model of farming keeps animals do indeed inflict extreme suffering — this style of farming is also becoming the norm.

Intensive animal agriculture requires massive and highly mechanized farms in which a single shed may contain thousands of animals severely crowded together. Most will never experience the warmth of sunlight, only artificial light that is sometimes kept on constantly to stimulate growth. They will not walk on soft grass, live among their families, care for their young or graze for food.

While intensive animal agriculture’s proponents claim that it helps to feed the world, food insecurity remains a dire global problem while the industry’s practices take a devastating toll on animals and the environment. The sole purpose of intensive animal agriculture is to feed a growing consumer demand for meat while maximizing profit.

Though Concentrated Animal Feeding Operations (CAFOs) are quite the opposite of an animal’s natural environment, they are now the reality of life for most farmed animals. In fact, a staggering 99 percent of U.S. farmed animals live on CAFOs.

Concentrated Animal Feeding Operations (CAFOs)

The difference between AFOs and CAFOs is largely a matter of size. CAFOs are highly intensive farms that typically house more animals than AFOs — sometimes tens of thousands of bodies.

A large CAFO also contains at least 1,000 pounds of “live weight” in animals. According to the EPA, this is equivalent to 1,000 cattle, 2,500 pigs weighing more than 55 pounds or 10,000 pigs weighing less than 55 pounds. For factory-farmed birds, a CAFO likely contains tens of thousands of animals: 30,000 broiler chickens or 55,000 turkeys.

Factory Farms

Factory farm is a common term for CAFOs, often used by opponents to describe the industrialized nature of these facilities and their capacity to confine extremely large numbers of animals. Though some advocates for large-scale farming now object to use of the term, “factory farming” was originally used by scholars to praise the industry’s increasing efficiency. 

Which Animals Are Useful for Agriculture?

All farmed animals have their uses to those who are farming them. But advocates of some methods of farming claim that their practices make certain animals less damaging than the standard practices found on CAFOs.

Livestock Rotation

In rotational grazing, the part of a pasture being grazed by feeding livestock is varied, so that other areas may be able to recover and regenerate. Some farmers will vary the species that is grazing in an attempt to add biodiversity, considered more effective by small farming researchers if a variety of vegetation is available. “As vegetation of pastures becomes more diverse, multispecies grazing tends to improve composition and utilization,” writes Lee Rinehart for the Cornell Small Farms Program. 

Yet the benefits of this practice are not entirely certain. While the U.S. Department of Agriculture (USDA) notes that there can be economic benefits for farmers and that soil erosion and agricultural runoff may be decreased along with other benefits, rotational grazing is not always practiced consistently.

“Rigid schedules reduce the benefit of rotational grazing,” notes the federal agency. Farmers often use an arbitrary pre-determined schedule to determine when they should relocate grazing animals, instead of assessing the growth rate of their forage. 

In addition, some advocates for regenerative agriculture claim livestock grazing can help store carbon emissions in the ground as an offset to climate change, but evidence shows any carbon gains in the soil are in fact usually short-lived, with the farming style requiring much more land at a steep environmental cost.  

How Many Animals Die Each Year Because of Animal Agriculture?

Globally, more than 70 billion land animals are slaughtered for human consumption every year. This figure comes from Faunalytics, using data from the United Nations Food and Agriculture Organization, although Faunalytics and others point out that there are questions regarding the accuracy of the FAO’s data. The Sentience Institute estimates that “at any given time,” 31 billion land animals and 38.8 billion to 215.9 billion fish are being farmed worldwide. 

Animal Agriculture’s Planetary Impacts

Factory farms, which produce massive amounts of waste, odor and noise, are most often built in low-income communities and communities of color, disproportionately impacting marginalized people, including the many undocumented immigrants who work in these facilities. The environmental impacts of intensive animal agriculture affect surrounding communities, their air quality and waterways, but they do not stop there. Factory farming is harming our environment with its damaging emissions, and advocates warn that most climate policies let the meat industry off the hook.

Animal Agriculture and Deforestation

Animal Agriculture and the Amazon

The Amazon rainforest is home to thousands of species of plants and animals and to Indigenous peoples who have long been fighting to keep and protect their land and this crucial ecosystem. An important natural resource in our fight against climate change, the Amazon has helped to store carbon dioxide from our atmosphere. Deforestation, though, has brought about an alarming reversal: the Amazon is now a carbon source, emitting more of the harmful gas than it is able to sequester.

While factory farms around the world may seem far removed from the plight of the Amazon and other forests, animal agriculture is largely to blame for their plight. Fires are intentionally set in the Amazon to clear land that will be used to grow crops for farmed animals. 

According to Our World in Data, three-quarters of global deforestation is “driven by agriculture,” with beef production alone responsible for 41 percent of deforestation. An investigation by the Instituto Centro de Vida released in February 2022 found that, despite an international moratorium, deforestation of the Amazon for soy production has continued. This problem is directly linked to animal agriculture, as nearly 80 percent of the world’s soy is not fed directly to humans, but fed to farmed animals raised for human consumption.

How Much Land Does Animal Agriculture Use?

Animal agriculture is clearing more and more land in the name of expansion and already takes up a staggering amount of space. 

Half of the habitable land on earth is used for agriculture, and the majority of that land — more than three-quarters, is used in the production of livestock. This is a massive and inefficient usage of land, out of all proportion with its benefits in terms of nutrient production. Animal agriculture contributes only 18 percent of our calories and 37 percent of protein, according to Our World in Data. 

Animal Agriculture’s Environmental Impact

Animal Agriculture and Biodiversity Loss

Biodiversity, a term for the necessary variety of plant and animal species in a habitat, is vital to the health of an ecosystem and even to human health — and it is increasingly at risk. Many experts believe that a sixth mass extinction is underway, as we are facing an “unprecedented” and “accelerating” loss of species. Animal agriculture shares in the blame for this alarming trend. 

A February 2021 report supported by the United Nations Environment Programme (UNEP) called the global food system “the primary driver of biodiversity loss,” with agriculture specifically named as a threat to 86 percent of species facing the threat of extinction. 

The good news is that there are ways to help address this problem. “Global dietary patterns need to move towards more plant-heavy diets, mainly due to the disproportionate impact of animal agriculture on biodiversity, land use and the environment,” writes the UNEP.

An April 2022 report by the Food Foundation tied plant-based eating to a direct positive impact on biodiversity. Its authors found that a plant-based shift in the U.K. could save 500 species from extinction.

Animal Agriculture and Air Pollution

Air pollution is considered “one of the greatest environmental risks to human health” by the World Health Organization, which ties outdoor air pollution to cancer, heart disease, stroke and lung disease. Factory farms release many pollutants and greenhouse gases into the air, including hydrogen sulfide, ammonia, nitrous oxide and methane — and much of the pollution is emitted by animal waste from industrial farms.

Experts have tied air pollution caused by factory farms to a decline in lung function in residents of surrounding communities, most severely impacting those with conditions causing chronic obstruction of the airways such as asthma or emphysema.

A study published in PNAS in May 2021 concluded that air pollution caused by agriculture results in 17,900 U.S. deaths per year. Animal agriculture was found to be largely to blame: Of 15,900 food production-related deaths, 80 percent were tied to livestock production or the production of feed for livestock.

Despite this threat to human health and the planet, most U.S. factory farms have a “free pass to pollute,” writes Devatha P. Nair, as they belong to one of the industries least regulated by the EPA. 

Water Pollution and Animal Agriculture

The farming of animals is a major contributor to water pollution. In 2017, the FAO reported: “The livestock sector is one of the top three contributors to the most serious environmental problems, including water-quality degradation, at every scale from local to global.” 

The FAO’s report tied the overuse and misuse of animal feed and drugs given to increase productivity to higher levels of pollution in aquifers, coastal waters, rivers and lakes. Most water used for livestock ends up back in the environment, often containing harmful pathogens or substances and “in intensive systems, also heavy metals, drug residues, hormones and antibiotics.” 

On large-scale dairy farms, the dumping of waste and even milk spills can cause significant damage, spurring the growth of bacteria, leaving water undrinkable and causing the deaths of aquatic species.

Animal Agriculture and Climate Change

The farming of animals is a leading driver, and even an accelerator, of climate change. Experts from the Intergovernmental Panel on Climate Change warn that the climate crisis is affecting us faster than we are able to adapt to it. Despite this dire threat, meat consumption is on the rise and factory farming continues to wreak havoc on our planet.

Animal Agriculture and Greenhouse Gas Emissions

While estimates of animal agriculture’s contribution to the release of greenhouse gasses (GHGs) vary widely — from 14.5 percent to over 37 percent, and even 87 percent — it is increasingly clear that the industry is responsible for a large portion of harmful emissions. It is also clear that changes to — and ideally, the elimination of — animal agriculture are needed if we are to address GHGs and their impacts.

A study published in PLOS Climate in February 2022 concluded that the “rapid global phaseout of animal agriculture” and a shift toward plant-based eating could stabilize GHG levels for the next three decades.

Why Is Agriculture Bad for Animals?

The production of meat, dairy and eggs inherently relies on the exploitation and slaughter of animals.

Animal Rights in Agriculture

From breeding to slaughter, farmed animals are considered property and treated as a mere means to a profit. They are afforded little to no legal protections. 

The Humane Methods of Slaughter Act is the only federal law governing the handling of farmed animals, and it has severe shortcomings, only covering the slaughter of animals and leaving out animals killed for food in the highest numbers — chickens and fish. Minimal protections for chicken, turkey and duck are covered under a different regulation, which requires that the birds “not die from anything other than slaughter after arriving at the slaughter facility.”

Delcianna Winders, a professor and Director of the Animal Law and Policy Institute at Vermont Law School, writes, “For decades, industrial animal agriculture has benefited from a hands-off approach in nearly every area of the law, at every level of government.”

Animal activists and animal advocacy organizations continue to fight to establish legal rights for farmed and other exploited animals. 

Intensive Confinement

Many farmed animals spend their short lives in intensive confinement, in the crowded and dark sheds that line factory farms — or even more extremely confined, as are the pigs kept in gestation crates during pregnancy and farrowing crates while nursing, or the egg-laying hens kept in battery cages so small they cannot turn around.

Efforts and legislation to address such confinement are often met with fierce opposition from animal agriculture. For example, Proposition 12, California’s landmark law banning the sale of pork, veal and eggs produced using the extreme confinement of animals has faced legal challenges after passing with a 63 percent majority in 2018, and animal advocates fear that it may be overturned.

Animal Abuse

Factory farming is a highly secretive industry, and laws known as Ag-Gag laws have only exacerbated that problem, keeping the public in the dark when it comes to the way animals and industry workers are treated.

Undercover work featuring hidden-camera footage and images captured by investigators and whistleblowers is often our best glimpse at what happens inside factory farms. Time and again, investigations reveal animal abuse that may be shocking to many consumers.

Many practices considered “standard” on factory farms, such as the debeaking of birds and castration of piglets without anesthesia, are in fact quite painful for animals. Other standard procedures like the routine separation of calves from their mothers on dairy farms also cause suffering in these animals. Other documented incidents of abuse include animals stabbed and kicked, slapped and shoved, thrown and stomped on — and often, in the case of those who cannot even survive long enough to make it to the slaughterhouse, culled or left to slowly die.

Is Animal Agriculture Bad for Human Health?

The agriculture industry often lauds industrial agriculture for its ability to efficiently feed the world. Yet intensive animal agriculture operations put not not only animals and the environment at risk, but human health as well. 

Animal Agriculture Causes Pandemics

The overcrowded and unhygienic conditions inside factory farms create the ideal environment for the spread of disease. Illness spawned in these farms not only impacts animals, but presents a potential danger to human health as well in the form of zoonotic disease — illnesses that can be transmitted between animals and humans. 

Dr. Aysha Akhtar, a neurologist and public health specialist as well the CEO of the Center for Contemporary Sciences, writes for Sentient Media, “Industrialized meat production is among the most dangerous enablers of zoonotic infectious diseases.” COVID-19 is a well-known illness that likely came from human use of animals, but there have been many other zoonotic outbreaks such as those of ebola, SARS and HIV.

Research has found that a shift towards plant-based diets could help reduce the risk of pandemics. 

Antibiotics in Animal Agriculture

Antibiotic resistance — a condition that leaves people vulnerable to “superbug” bacterial infections that cannot be treated with medications — is on the rise. In fact, the World Health Organization states that this resistance is “rising to dangerously high levels in all parts of the world.” 

Factory farms fuel this threat through the widespread use of antibiotics. These powerful drugs are given to farmed animals by injection or in their feed in an attempt to prevent the spread of illness — and to promote growth in farmed animals in order to maximize meat production and profit — yet their rampant overuse is now linked to a rise in antibiotic resistance.

The use of antibiotics in animal agriculture is so widespread that it may be hard for consumers to know whether the meat they are purchasing is affected by this practice. In April, research by Farm Forward found antibiotic residue in meat sold as “antibiotic-free” by Whole Foods.

Antibiotic resistance affects not only humans, but animals as well — including farmed animals. Farmers have said that they are already seeing reduced effectiveness of these drugs to stop disease and infection.

Worker Health

U.S. meat production is widely considered to be one of the most dangerous industries in the nation.

Data from the Occupational Safety & Health Administration (OSHA), as analyzed by the Guardian and the Bureau of Investigative Journalism in May 2018, reveals that among workers in U.S. meat plants, there are an average of two amputations each week and that monthly there are an average of 17 incidents considered by OSHA to be “severe” — involving the loss of an eye, an amputation or hospitalization. Despite the many accidents that take place, some workers have said their injuries were ignored by supervisors.

On factory farms, workers are also subjected to long-term exposure to animal waste and ammonia, and research has found they are at increased risk for respiratory diseases.

What Is the Future of Animal Agriculture?

The science is increasingly clear: our consumption of meat and other animal products simply cannot continue at the current rate if we are to fend off the worst impacts of climate change. It remains to be seen whether governments will take action to force meat, dairy and egg producers to reduce their environmental impact, and whether consumers will, in larger numbers, turn away from animal products and towards more sustainable plant-based alternatives.

One factor that may determine the future of animal agriculture is the unprecedented innovation taking place in the field of cultured protein, also known as lab-grown or cultivated protein. From chicken to seafood and more, startups are creating real meat that is produced from the cells of animals but removing slaughter from the equation. While not considered suitable for a vegan diet, for other consumers it could be a revolution.

Cultured protein still awaits regulatory approval in most places, so it is not yet widely available to consumers around the world. Seren Kell of the Good Food Institute Europe told the Guardian in December 2021 that this technology could have “huge environmental, public health and food security benefits,” but to make it happen, “we need governments to invest billions in research and commercialization.” 

Animal Agriculture: Facts and Statistics

An estimated 90 percent of farmed animals around the world, including “virtually all farmed fish,” are raised in factory farms, according to the Sentience Institute. This means that nearly all of the animal flesh and byproducts we consume are coming from intensive livestock operations.

There are an estimated 25,000 factory farms in the U.S. The total number of farms in the country has been steadily decreasing since the 1970s as smaller farms vanish in favor of large-scale operations. There are approximately 1.6 billion farmed animals nationwide.

What You Can Do

The most effective way to help farmed animals in your daily life is to eliminate meat, dairy, eggs and other animal products from your diet. Browse ChooseVeg.com for recipes, guides and other tips to help you get started.

Plus, visit Sentient Media’s Take Action page, where you will find many simple and effective ways to stand up for farmed animals and stand with organizations and advocates working on their behalf.