Factory Farming: A Recipe for Disaster for Animals & Our Planet

In traditional farming, animals distribute their waste as they move, which can be beneficial to the land. With industrial operations, tens of thousands of animals are housed in sheds or pens, which, in addition to causing frustration, stress and painful ailments for animals, leads to massive build-ups of manure. It's estimated that every minute, nearly 2 million pounds of excrement are produced by animals raised on CAFOs in the U.S.

Unlike human waste, manure from CAFOs is not treated and typically gets flushed into underground pits or lagoons that are several acres wide. It is stored there until it is applied as fertilizer on fields. But the quantity of waste produced on factory farms cannot easily be absorbed, resulting in over-application and runoff of the manure—and all of the chemicals, toxins and bacteria it contains—into local waterways. It is also common for the pits or lagoons to leak, break or overflow, contaminating groundwater. Animal agriculture is the leading polluter of U.S. rivers and streams, the second-largest source of wetlands contamination, and the third-largest source of lake pollution.

As a result, CAFOs have severe impacts on aquatic health as excessive nutrient concentrations from manure, such as nitrogen or phosphorus, can make water uninhabitable or cause harmful algal blooms. Rural communities rely heavily on groundwater wells for drinking water, and the Environmental Protection Agency’s 2000 National Water Quality Inventory found that 29 states specifically identified CAFOs as contributing to drinking water quality impairment. Cleanup expenses from CAFOs have cost municipal water systems over $1.1 billion over the past 10 years.  

While pollution is a more visible problem, the immense water demand from CAFOs has alarming environmental and community impacts as well. Globally, agriculture uses more freshwater than any other human activity, and about one-third of that water is for livestock production.

Private residential water use makes up 5% of total consumption in the U.S. In contrast, animal agriculture makes up 55% of total water consumption. In the time it takes to brush your teeth, U.S. animal agriculture uses more than 209 million gallons of water.

• Drinking water for farm animals accounted for water withdrawals of 2 billion gallons per day, mostly from fresh, groundwater sources, and are the equivalent to the amount of water consumed by 20,000 households over the course of an entire year. 

While animals do drink a lot of water, in the U.S., up to 98% of the water involved in livestock production was used to grow animal feed.

Raising animals in crowded conditions indoors surrounded by their own waste affects air quality inside the facilities, leading to high concentrations of ammonia, hydrogen sulfide, carbon dioxide and particulate matter (small particles that can be inhaled). This in turn impacts animals’ welfare, causing issues like respiratory diseases in cattle raised in feedlots and ammonia-induced eye and skin problems in chickens. Airborne contaminants from manure and dust also pollute the air in surrounding communities, pushed out of the facilities by ventilation systems in CAFO buildings and vaporized after manure is applied to land as fertilizer.

A recent study showed that agriculture in the U.S. results in over 12,000 air quality-related deaths attributable to animal agriculture each year. Ammonia and particulate matter from factory farms can cause asthma, bronchitis and other breathing problems, and long-term exposure to these emissions increases the risk of dying of heart disease, cancer and stroke. In addition to inhaling toxins, communities near CAFOs are plagued by noxious smells from manure lagoons, decreasing quality of life and home/property values, and causing serious mental health issues, including depression and anxiety.

While the transportation and energy sectors are often called out for their role in climate change, it’s less understood that animal agriculture is responsible for 14.5% of all human-made greenhouse gases. Factory farms emit methane and nitrous oxide which are up to 300 times more damaging as greenhouse gases than carbon dioxide.

The greatest contributor to overall emissions from animal agriculture is the enormous production and processing of feed crops like corn and soybeans, which are the exclusive source of food for pigs and poultry species raised indoors on CAFOs and a significant portion of dairy and beef cows’ diet.  

Unlike animals raised on pasture who can graze—or in the case of pigs and birds, supplement their feed with forage and bugs—animals raised in confinement are restricted to grain-based feed for their entire lives. Nearly half of all corn and 70% percent of soy grown in the U.S. is produced to feed animals raised in CAFOs, and those crops rely on fossil fuels and use enormous quantities of chemical fertilizers and pesticides.

Soy production has been shown to cause waterway eutrophication (when water becomes uninhabitable due to excess nutrients) from fertilizer nutrient runoff and heavy herbicide application—herbicides were applied to 98% of planted soy acres in 2020. Most herbicides contain glyphosate, which may persist in soil, plants and water, reaching both surface water and groundwater—potentially changing the soil’s properties and growth and even causing human toxicity.

Similarly, corn fields growing for animal agriculture are heavily fertilized for maximum output. The excess nitrogen contributes to both waterway eutrophication and fine particulate matter air pollution.

Some researchers have pointed out that beef production contributes the most to greenhouse gases and encourage consumers to “eat smaller” by consuming more poultry and fish. EPA data shows that beef and dairy production account for almost 80% of agriculture’s greenhouse gas emissions. But while poultry and some pork have lower production-related emissions, simply switching from beef to chicken is not a climate-friendly choice, and it does more harm to more animals. Alarmingly, it takes 134 chickens to get the same amount of meat as one cow, so as consumers swap beef for chicken, billions more animals suffer on factory farms.

Chicken CAFOs contribute heavily to air and water pollution and greenhouse gas emissions through feed production, fossil fuel use and manure management. One area where the pork, poultry and dairy industries’ environmental footprints equal or outweigh that of beef is in manure management, which represents a significant portion of livestock’s emissions. Poultry litter has been shown to contaminate surrounding waterways with excess nutrients such as nitrogen and phosphorous, causing dead zones and introducing pathogens including antibiotic-resistant bacteria. As this waste is applied to fields, the impact is felt in waterways. Poultry products also have a significant environmental footprint because of the reliance on pesticide- and herbicide-laden feed crops in a CAFO setting, as opposed to beef cattle and dairy cows, who sustain themselves on grass for at least part of their lives.

Plant production doesn’t create emissions from animals’ digestion and manure, and eating crops is simply more efficient than eating an animal who consumed crops. For this reason, the United Nations’ IPCC Report on Climate Change identified that shifting diets from animal- to plant-based food has the power to help us fight climate change by drastically cutting our greenhouse gas emissions:

• The average American could cut their diet-related environmental impacts by nearly half just by eating less meat, eggs and dairy.
• If everyone in the U.S. swapped conventional meat and cheese for plant-based products just one day a week for a year, it would be like taking 7.6 million cars off the road. 
• That same small change multiplied across the entire U.S. population would also spare a staggering 1.4 billion animals from slaughter annually.

Most of the leading ingredients in plant-based alternatives[PDF] to beef, pork and chicken (wheat, soy, peas, mushrooms) use less water than their animal equivalents when factoring in both the water consumed by the animals and water used to grow the crops that feed them. Consumers can reduce animal product consumption by choosing alternative products with ingredients that have lower water usage.

Plant-based alternatives lack all of the water pollution caused by the accumulation of animals’ manure, but plant-based products aren’t perfect when it comes to water pollution from certain crops, like soy, which is both in animal feed and an ingredient in some plant-based meat and dairy alternatives. Soy may contribute to waterway eutrophication (when water becomes uninhabitable due to excess nutrients) from both fertilizer nutrient runoff and heavy herbicide application. Wheat—a key ingredient in many beef and chicken alternatives—also relies heavily on herbicides, with anywhere from 66% to 97% of planted acres treated in 2019. Herbicides used on wheat fields have been classified as “very toxic to aquatic life with long lasting effects.” Wheat also relies on heavy fertilizer use, risking excess nutrient runoff from applied fields into waterways, causing eutrophication. Canola oil, used in some dairy alternatives, commonly involves using the volatile organic compound solvent Hexane to extract the oil. Almonds often include the application of glyphosate. Even oats rely on two main herbicidal active ingredients, one of which includes glyphosate.

Half of the world’s habitable land is used for agriculture, most of which is used to raise farmed animals or feed them: animal agriculture accounts for 77% of global farming land. While livestock takes up most of the world’s agricultural land, it produces only 18% of the world’s calories and 37% of total protein, and the demand for land for animal agriculture is the leading driver of deforestation and biodiversity loss. Research suggests that if everyone shifted to a plant-based diet, we would reduce global land use for agriculture by 75%. This would benefit the planet and animals alike as habitats could be restored with carbon-capturing forests and meadows.

Because manure on pasture-based farms is generally not stored in lagoons or pits, pasture-based systems have greatly reduced risks of water impairment events since they don’t run the risk of manure leaching into groundwater or runoff into local waterways.

Farm animals in CAFOs require significant amounts of water both for drinking and as an input for the massive amounts of grain required for feed. When ruminant animals (beef cattle, dairy cows, sheep, goats) are pasture-raised, they rely on grasses that are predominantly rain-fed and store moisture in the soil, thus reducing water usage in the system. While CAFOs and grain production deplete water reserves, pastures that include a diverse mixture of grasses, legumes and broadleaf plants, including drought-resistant species, can often withstand water shortages. 

Further benefits to water are gained through pasture-based farming’s reduced reliance on feed crops. Corn and soy are water-intensive products which, when grown for conventional feed crops, tend to pollute waterways. Soy production has been shown to cause waterway eutrophication (when water becomes uninhabitable due to excess nutrients) from fertilizer nutrient runoff and heavy herbicide application. Most of the herbicides contain glyphosate —which may persist in soil, plants and water, reaching both surface water and groundwater,—potentially changing the soil’s properties and growth, and even causing human toxicity. 

Similarly, corn grown for animal agriculture is heavily fertilized for maximum output and the excess nitrogen contributes to waterway eutrophication. Alfalfa also commonly relies on herbicides and pesticides.

Grazing animals distribute manure in sustainable amounts directly on the land, building soil health and recycling nutrients. The U.S. is losing an unsustainable amount of nutrient-rich topsoil each year, in large part because of practices used to grow corn and soy for animal feed. Well-managed grazing returns nutrients to the soil—moderate amounts of manure act as natural fertilizers for the soil. Compared with row crops, pasture-raising animals reduces soil loss by as much as 93%. Integrating livestock into crop rotations can control weeds, increase yields and reduce fertilizer use.

Manure distributed by animals on pasture emits fewer toxins and greenhouse gases than lagoon or pit manure storage associated with factory farming. One study showed that shifting pigs to pasture-based systems could realize a 29% reduction in nitrous oxide emissions and a 7% reduction in methane emissions when compared to the emissions of an industrial factory farm.

For pasture-based systems to have a relatively beneficial impact on greenhouse gas emissions, the animals’ movement and the pasture itself needs to be closely managed. A study showed that farm animal management systems such as “adaptive multi-paddock grazing” have the potential to cut livestock emissions by more than half when compared to intensive CAFO systems.

Well-managed grazing -- where animals are moved regularly to allow the pasture to rejuvenate and pastures are seeded with high quality forage that accelerates animals’ growth -- can help restore degraded rangeland and increase soil carbon sequestration (the re-capture of carbon) through plant growth and improved soil health. The Food & Agriculture Organization estimated that improved grazing management practices on current grasslands had the combined potential to trap the equivalent of 585 million tons of carbon over 20 years, representing about 8% of livestock supply chain emissions. With reduced demand for factory farmed animal products, the conversion of land currently used to grow conventional feed crops into well-managed pastureland could further offset the greenhouse gas emissions of animal agriculture.

While conversion of land used for feed crops to pasture could have benefits to the environment, other types of land conversion to expand pasture-based farming, such as converting forest to pasture, has the opposite effect and instead leads to an increased carbon footprint.