A few related points
Americans' appetite for meat and dairy – billions of pounds a year from billions of animals – takes a toll on our health, the environment, climate and animal welfare. Producing all this meat and dairy requires large amounts of pesticides, chemical fertilizer, fuel, feed and water. It also generates greenhouse gases and large amounts of toxic manure and wastewater that pollute groundwater, rivers, streams and, ultimately, the ocean.
In addition, eating large quantities of beef and processed meats increases your exposure to toxins and is linked to higher rates of health problems, including heart disease, cancer and obesity.
While best management practices can demonstrably reduce overall emissions and environmental harm, the most effective and efficient way to reduce greenhouse gas emissions and environmental impacts from livestock is simply to eat, waste and produce less meat and dairy.
Sources of emissions - Feed Production
Grain production, in particular, requires significant quantities of fertilizer, fuel, pesticides, water and land. It takes 149 million acres of cropland, 76 million kilos (167 million lbs) of pesticides and 7.7 billion kilos (17 billion lbs) of nitrogen fertilizer to grow this feed. Fertilizer applied to soil generates nitrous oxide (N20), which has 300 times the warming effect of carbon dioxide. Animal waste releases nitrous dioxide and methane and pollutes our water and air, especially when it is concentrated.
Sources of emissions - Manure
In 2007, U.S. livestock in confined feeding operations generated about 500 million tons of manure a year, three times the amount of human waste produced by the entire U.S. population (EPA 2007). Manure is the fastest growing major source of methane, up 60 percent from 1990 to 2008 (EPA 2010) .
While manure is a valuable nutrient for plants, it can leach pollutants – including nitrogen, phosphorus, antibiotics and metals – into groundwater when storage facilities leak or too much is spread on farm fields. More than 34,000 miles of rivers and 216,000 acres of lakes and reservoirs in the U.S. have been degraded by waste from confined feeding operations (EPA 2009). Decomposing waste releases dust, smog odors and toxic gases, including ammonia and hydrogen sulfide, which degrade air quality and can cause itching, dizziness and discomfort to workers and nearby residents.