;The Environmental Concerns of the Livestock Industry The United States leads the way in a global trend toward increased meat consumption. The average American consumes almost twice his or her own body weight in meat every year. World meat production has surged nearly fivefold in the last fifty years, from 44 millions tons in 1950, to 211 million tons in 1997. This growing manufacturing of meat for food is creating new pressures on land and water resources, contributing to water pollution, and intensifying global warming (Worldwatch Institute). The media places emphasis on the environmental damage caused by oil spills, pollutants emitted from motor vehicles, ozone depletion, and acid rain. The environmental concerns associated with the manufacturing of nuclear power and paper products are widely-known. Commonly overlooked are the hazardous effects of raising animals for food. The livestock industry has many negative effects on the environment, including pollution of the air, land, and water resources. The improvement of management practices in the livestock industry can lead to the reduction of harmful effects on the environment, and at the same time, increase profits. The Ruminant Livestock Efficiency Program and the Global Livestock Group are programs concerned with cleaning up the air. The Environmental Quality Incentive Program targets the cleanup of livestock waste, and the reduction of meat consumption is a method of preserving land and water resources. The implementation of more efficient management strategies in livestock production can lead to maximized environmental and economic benefits. Methane Emissions According to the Environmental Protection Agency, the world s livestock herds account for approximately 25 percent of human-induced emissions of methane (CH4), a colorless and odorless, but potent, greenhouse gas that contributes to climate change (Worldwatch Institute). Methane is one of the principal greenhouse gases, second only to carbon dioxide (CO2), and with a global warming potential twenty-one times greater. Methane made an estimated contribution of 18 percent to the radiative forcing of the climate in 1990. A potential effect of climate change includes increased frequency of extreme weather events, such as floods, drought, and severe storms. Changes in precipitation and temperature patterns could jeopardize current agricultural practices, and tropical diseases and pests could increase their range. In addition, raised sea levels could threaten vulnerable coastlines around the world (Environmental Protection Agency). Domesticated ruminant (cud-chewing) animals, with an ever-increasing population, constitute the largest source of anthropogenic methane emissions. Ruminants, such as cattle, sheep, and goats, have a unique, four- chambered stomach. In the large chamber of the stomach called the rumen, microbial fermentation in the animal s digestive system breaks down food into soluble products that the animal can utilize. Ruminant animals are unique because their special digestive system allows them to convert otherwise unusable plant materials into nutritious food and fiber. However, this microbial fermentation process, referred to as enteric fermentation, produces methane gas as a by-product, which is exhaled by the animal (Center for International Earth Science Information Network). The production rate and amount of methane created is affected by factors such as quality and quantity of food, body weight, age, and exercise. Inefficient feed utilization leads to high exhaled methane emissions, and ruminants on low quality feeds produce more than 75 percent of the total livestock methane emissions. In many emerging market countries, animal diets consist mainly of low quality feed such as rice straw and sugarcane tops that lack the daily nutrients necessary for efficient digestion (Global Livestock Group). Of the annual global production of 400 to 600 million tons of methane, ruminant livestock produce about 80 millions tons, or 22 percent. An adult cow may emit only eighty to 120 kilograms of methane, but with about 100 million cattle in the United States and twelve billion large ruminants worldwide, it is easy to see why ruminants are one of the largest methane sources (Environmental Protection Agency). Besides the methane production of the digestive process, the stagnant waste lagoons of factory-farm operations emit an additional 5 percent of human-induced methane (Worldwatch Institute). In addition to methane, animal agriculture also leads to the emission of other greenhouse gases into the air. The production of feed and heating of livestock housing uses fossil fuels which emit carbon dioxide, and the growing of livestock feed requires intense use of synthetic fertilizer, releasing nitrous oxide. These gases, along with methane, have significant impact on the earth s atmosphere, and are major contributing factors to global warming (Vegan Outreach). Land Destruction The production of beef depends heavily on rangelands. These areas are too arid or too steeply sloped to be plowed, so meat production is the only option for generating food from these ecosystems. As overgrazing becomes the norm in much of the world, rangelands are being pushed to their limits and beyond. Improper grazing has caused extensive environmental damage and rangeland degradation. The fragile state of the world s rangelands is of serious concern because these lands are the source of almost one-quarter of the world s meat. In addition, in some parts of the world, the escalating demands of the world s rangelands are threatening the livelihood of herder populations and cultures, which revolve around animal husbandry (Worldwatch Institute). Topsoil erosion is also a serious problem. Topsoil is lost at a rate of one inch every sixteen years and the meat industry is directly responsible for 85 percent of all soil erosion in the United States. This is because so much grain is needed to feed animals being raised for food. Growing feed for utilization by the livestock industry changes land use, therefore harming biological diversity through habitat loss and ecosystem damage (Vegan Outreach). Vast ecosystems have been altered in order to support livestock populations. This includes forest destruction for ranching, suppression of native predators and competitors, and the introduction of invasive forage species. Of all agricultural land in the United States, 87 percent is used to raise animals for human consumption. About 260 million acres of forest in our country have been cleared to create cropland to support the livestock industry, and another acre of trees disappears every eight seconds (Tax Meat). In addition, the greatest loss of tropical rainforests in the world is to make space for cattle grazing. Fifty-five square feet of rainforest may be wiped out to produce just one quarter-pound burger. The soil is virtually useless once the rainforests have been destroyed, and the land will sustain pasture for only four or five short years (country CONNECTIONS). Livestock herds do not only occupy the land and feed off it. They pollute it as well. Animal waste is spread upon the land, giving off ammonia, which is a major cause of acid rain. In addition, the waste is full of the heavy metals that are added to feed, which then accumulate in the soil in serious proportions and lead to water pollution (Animal Rights Resource Site). Water Contamination The huge quantities of waste produced by livestock threaten the world s water resources. The meat industry is the single greatest polluter of our waters. Rivers and streams are carrying ever-larger volumes of nutrient pollution, the biggest single source of which is livestock waste. The waste enters fresh waters either directly or as runoff from the land and is very effective at depleting natural waters of their oxygen. It can also affect the microbial quality of fresh waters (Environment Agency). Livestock wastes are implicated in waterway pollution, toxic algal blooms, and massive fish kills. In the United States, waste generated by livestock amounts to 130 times that produced by humans. Livestock farms are getting larger throughout the world, and one 50,000 acre farm can produce more waste than the entire city of Los Angeles (Worldwatch Institute). Livestock waste is the biggest single cause of declining fish populations in 60,000 miles of polluted waterways in the United States, and another 113,000 miles of waterways are seriously affected. Pollution from factory farms harms more miles of U.S. rivers than all other industry sources and municipal sewers combined (country CONNECTIONS). Polluted waters foster the growth of pathogenic microorganisms that can be fatal to fish and cause sickness in humans. Pfiesteria is a microscopic organism that kills fish and can cause lesions, memory loss, dizziness, fatigue, and asthmatic problems in humans. This organism is most at home and multiplies at a tremendous rate in polluted, over-enriched waters. Most of our nation s 127 estuaries show symptoms of nutrient overload. This can also spawn algae blooms that strip the waters of oxygen as they decompose, proving fatal for many fish (EarthSave International). Other potential and actual pressures on the environment from the production of livestock arise from the use of fertilizers, veterinary medicines, and other chemicals. Any excessive use of nutrients and inexpert use of pesticides can place severe pressures on the quality of both surface and ground waters. Drinking water can become contaminated if these substances leach into underground water bodies, and pesticides that enter surface waters are toxic to fish and other aquatic life (Environment Agency). One of the principal ways of handling waste from factory farms is the use of lagoons. Waste is stored in these massage earthen pits until it decomposes. Leakage from waste-disposal lagoons makes its way to waterways, killing huge numbers of fish, and contaminating drink water (EarthSave International). In addition to water contamination, meat production has a growing impact on nations