With over nine billion animals raised and slaughtered for human consumption each year in the U.S. alone, modern animal agriculture puts an incredible strain on natural resources like land, water, and fossil fuel. Factory farms yield a relatively small amount of meat, dairy, and eggs for this input, and in return produce staggering quantities of waste and greenhouse gases, polluting our land, air, and water and contributing to climate change.
In the U.S., animals raised on factory farms generate more than 1 million tons of manure per day — three times the amount generated by the country’s human population.
Factory farms typically store animal waste in huge, open-air lagoons, often as big as several football fields, which are prone to leaks and spills. In 2011, an Illinois hog farm spilled 200,000 gallons of manure into a creek, killing over 110,000 fish.
When lagoons reach capacity, farmers will often opt to apply manure to surrounding areas rather than pay to have the waste transported off-site. According to the USDA, animal waste can contaminate water supplies and omit harmful gases into the atmosphere when over-applied to land.
During digestion, ruminants like cattle, sheep, and goats emit methane, an infamous “greenhouse gas” and key contributor to global warming. The EPA has estimated that, between 1990 and 2005, methane emissions from pig and cow operations rose 37 percent and 50 percent respectively, largely due to the greater amount and concentration of manure in lagoons and related storage systems.
In order to prevent the spread of disease in the crowded, filthy conditions of confinement operations, and to promote faster growth, producers feed farm animals a number of antibiotics. Upwards of 75 percent of the antibiotics fed to farm animals end up undigested in their urine and manure. Through this waste, the antibiotics may contaminate crops and waterways and ultimately be ingested by humans.
The demand for livestock pasture is a major driver of deforestation. The Food and Agriculture Organization of the United Nations has estimated that 70 percent of land formerly supporting Amazon rainforests has been turned over to grazing.
Between watering the crops that farm animals eat, providing drinking water for billions of animals each year, and cleaning away the filth in factory farms, transport trucks, and slaughterhouses, the animal agriculture industry has a huge impact on the water supply. Producing one pound of beef takes an estimated 1,581 gallons of water, which is roughly as much as the average American uses in 100 showers.