Over the last fifty years, the industrial farm animal production industry (IFAP), or factory farming industry, has grown rapidly and now produces the majority of meat consumed globally. Most interest groups including Farm Forward and activist/author Jonathon Safran Foer estimate that about 99% of all meat is now produced by factory farms.

Foer even claims that “Americans eat the equivalent of 21,000 animals in a lifetime.”

This might seem shocking, but in 2011 the USDA reported that in the United States alone, 34.1 million head of cattle, 852 200 calves, 110.9 million hogs, and 2.16 million sheep were slaughtered for human consumption.

The rearing and slaughter of such large quantities of animals has produced a number of environmental consequences.

A 2008 report by the Pew Commission entitled “Putting Meat on the Table: Industrial Farm Production in America” identifies a number of these consequences, but the foreword by former Kansas Governor John Carlin summarizes the main concern with factory farming.

Carlin said, “the industrial farm has brought about [a] tremendous increase in short-term farm efficiency and affordable food, but its rapid development has also resulted in serious unintended consequences and questions about long-term sustainability.”

Indeed, all questions about the ethics of the industry aside, factory farming has led to a number of serious environmental issues that in the long-term may pose serious risks.

Environmental concerns of factory farming

The key issue at stake is the long-term sustainability for maintaining current practices of factory farming, which changed to meet an increased demand for inexpensive meat.

One of the most pressing issues is the amount of methane that is released into the atmosphere as a result of raising such large numbers of animals.

Cattle and hogs are ruminant livestock whose digestive processes release methane. Cattle can release between 80-110 kilograms of methane in their lifetime, a relatively small amount.6But according the Environmental Protection Agency (EPA) there are about 100 million head of cattle in the US alone and about 1.2 billion globally. In total, this accounts for about 5.5 million metric tons of methane being released into the atmosphere every year, or about 28% of global methane emissions. Methane, as a greenhouse gas, directly contributes to the acceleration of climate change.

There is global concern about the increasing amounts of carbon dioxide being released into the atmosphere, but methane is actually of greater concern because it has the ability to trap heat 21 times more effectively than carbon dioxide.

Much of the methane that cattle produce is a result of their natural diet, which consists of low-protein grasses, brush, and other foraged plant materials. The four stomachs of a cow are designed to digest these materials and the rumen of the four stomachs helps to break these materials down, producing methane as a by-product.

However, for cattle, the process of factory farming is completed on feedlots where they are fed high-protein diets of soy and corn by-products for rapid growth. Cattle are not designed for high-protein diets and eventually the methane-producing microorganisms in the rumen shut down and the cattle stop producing methane. This might appear to be a benefit to process of factory farming, but in reality, it creates another environmental problem.

Excess protein is expelled from the body as urinary nitrogen. In large quantities, such as in feedlots, the excess nitrogen can vaporize and turn into ammonia gas, or acid rain. Acid rain is problematic because it can kill insects and aquatic life, change pH levels in the soil which kills important microbes, as well as pose serious health risks for humans.

Another by-product of factory farming is manure, which if used appropriately, can actually be beneficial.

Manure contains organic matter and nutrients such as nitrogen that when spread properly over agricultural fields can help cultivate soil fertility.

The Organic Trade Association encourages the use of manure, stating that, “composted manure is a primary source of soil fertility for organic farmers. It offers a natural means to cycle plant nutrients. As such, animal manure forms an important part of organic soil fertility programs.”

However, there are issues even with the proper use of manure from factory farm facilities. Manure and other animal waste are often collected underneath the animal pens and then piped out into anaerobic lagoons beside the animal housing facilities. The manure then settles and separates into two layers, a solid layer and a liquid layer. The lagoon then undergoes anaerobic respiration, a process in which organic compounds are turned into carbon dioxide and methane gas, which is then released into the atmosphere.

It is important to note that the manure stored in these lagoons also contains the chemicals and bacteria expelled from the animals, including antibiotics, fertility drugs, hormones such as estrogen and harmful bacteria which are spread onto fields used for agriculture.

An additional problem with these lagoons is that they cannot keep up with the amount of waste being pumped into them.

The National Resources Defense Council (NRDC) states that “these cesspools often break, leak or overflow, sending dangerous microbes, nitrate pollution and drug-resistant bacteria into water supplies. Factory-farm lagoons also emit toxic gases such as ammonia, hydrogen sulfide and methane. What’s more, the farms often spray the manure onto land, ostensibly as fertilizer — these “sprayfields” bring still more of these harmful substances into our air and water.”

The criticisms of the NRDC are twofold; first, that damage can be “sudden and catastrophic” in the event of a leakage that gets into groundwater and kills wildlife, fish and pollutes drinking water and second, that damage can be “cumulative,” such as when manure is applied in excess and over-saturates the soil.

Searching for a resolution: a shift toward sustainability

There are in fact even more environmental risks associated with factory farming beyond methane and ammonia pollution. Demand for grazing space is the largest contributor to deforestation globally, especially in the Amazon rainforest. Biological problems include loss of genetic diversity within livestock breeds and loss of biodiversity due to eutrophication.

The vast majority of activist groups associated with the issue of factory farming, including People for the Ethical Treatment of Animals (PETA), advocate a switch to vegetarianism as the only way to address the risks of factory farming.

This, however, is not a plausible reality in the short term. Instead, other interest groups are advocating for a switch to more sustainable farming practice, some of which would be relatively easy to implement.

The Pew Commission suggests that factory farms can install biofilters as a method for controlling emissions, claiming that they can cut ammonia emissions by up to 80% at relatively low costs. Biofilters are made from organic material such as wood chips or compost that is wrapped in fabric. They convert compounds in the air into carbon dioxide.

The Commission also suggests community-supported agriculture (CSA) as an alternative to factory farms. CSA works through the “commitment between a farm and a community of supporters that provides a direct link between the production and consumption of food. CSA members cover a farm’s yearly operating budget by purchasing a share of the season’s harvest, supporting the farm throughout the season, sharing both the costs and the bounty with the farmer.”

At its core, CSA is a reversion back to grass-roots family-run farms that are inherently more environmentally sustainable than factory farms due to the fact that they only raise animals that the land can support.

The awareness group Beyond Factory Farming states that some of the key tenants of sustainable farming include a recognition that the surrounding environment must be protected, a natural growth cycle for animals that excludes the use of growth hormones or antibiotics, protection and conservation of water resources and the responsible use of manure as a fertilizer.14

The NRDC suggests that raising public awareness is the first step to changing the nature of the farming industry. They also encourage the government to support alternative farming methods.

A 2011 bulletin states, “states and the federal government should promote methods of raising livestock that reduce the concentration of animals and use manure safely. Many alternative methods exist; they rely on keeping animal waste drier, which limits problems with spills, runoff and air pollution.”

The NRDC also calls for tougher legislation on existing factory farms that forces them to take responsibility for the environment effects of their practices.

NRDC report on the threats of factory farming on public health states that, “factory farms are industrial facilities and should be regulated accordingly. They must obtain permits, monitor water quality and pay for cleaning up and disposing of their wastes.”

The inevitability of sustainability

It is true that factory farms have increased the efficiency of meat production by increasing outputs and reducing overall costs. Changes in the types of feeds utilized, to housing facilities to the use of hormones to speed growth have all been contributing factors.

But it is important to note that factory farms are dependent upon water and fossil fuels to run and that water and fossil fuels are finite. By their very nature, they will eventually run out and this will force a change within the industry. This point is made by the Pew Commission.

Their report states, “…IFAP systems are almost entirely dependent on fossil fuels. The nitrogen used for fertilizer to produce animal feed is derived from natural gas. Phosphorus and potash are mined, processed, and transported to farms with petroleum energy. Pesticides are manufactured from petroleum resources. Farm equipment is manufactured and operated with petroleum energy. Feed is produced and trucked to concentrated animal operations with fossil fuels. Manure is collected and hauled to distant locations with fossil fuels.”

Furthermore, the cost of feeding livestock will increase as they are traditionally raised on corn and soy-based feeds. However, the use of corn and other commodity crops in biofuels and their linkages to the energy sector will also increase feed costs.

Changes in the global climate from global warming will also have an effect on commercial meat production. Droughts may be experienced more frequently, with this year’s past drought in the United States driving up the cost of food. Feeding such large quantities of animals will become more and more expensive.

At the end of the day, while factory farming may be inherently environmentally unstable, changing the process will require a conscious effort by consumers who desire to see a change.