The Environmental Impact of a Meat-Based Diet

I always knew that becoming a vegetarian would help prevent cruelty to animals but I was not aware of the environmental consequences of a meat-eating diet. The production of beef and other animal protein consumes huge amounts of natural resources such as water, fossil fuels and topsoil, while polluting our water and air. In fact, switching to a plant-based diet from a meat-eating diet is the single most important move I can make to help the environment, much more effective than turning off the water when I brush my teeth or recycling and reusing. (Although, I will always continue to conserve and recycle!)

One of the biggest environmental impacts of a meat-eating diet is the depletion of natural resources, particularly the consumption of vast amounts of water for livestock production. Today, there are more than 17 billion livestock in the world; that’s about triple the number of people. Raising these animals requires huge amounts of water, most of it used to irrigate the grains and hay fed to the animals. According to the Water Education Foundation, it takes 2,464 gallons of water to produce one pound of beef in California. This is the same amount of water you would use if you took a seven-minute shower every day for six entire months. In contrast, only 25 gallons of water are needed to produce one pound of wheat. Present human water consumption drains aquifers around the world. Water tables are dropping drastically and wells are going dry. The United States Geological Survey says that 40 percent of fresh water used in the U.S. in 2000 went to irrigate feed crops for livestock. Only 13 percent was used for domestic purposes including showers, flushing toilets, washing cars and watering lawns. Switching to a plant-based diet or reducing the amount of meat in your diet is by far the most important choice you can make to save water.

Raising livestock depletes other natural resources as well, including fossil fuels and topsoil. Aside from the cost of grains used to feed livestock you can also measure the cost of fossil fuel energy. Agricultural production uses ten percent of the energy used every year in the United States. David Pimentel from Cornell University explained it this way, 40 calories of fossil fuel are needed to produce one calorie of protein from feedlot beef while only two calories of fossil fuel are needed to produce one calorie of protein from tofu.

Topsoil is another vital natural resource being used faster than nature can replace it. The production of corn and soybeans, the major grains fed to livestock, causes massive soil erosion because those crops are grown in rows. The bare patches between the rows expose the topsoil to both wind and rain erosion. Pimentel has calculated that in Iowa one half of the topsoil has been lost due to farming over the past 100 years. It is estimated that we lose nearly 7 billion tons of topsoil every year.

Another natural resource that is being threatened today by the increased production of livestock is the rainforest. According to the Nature Conservancy, every second of every day one football field of rainforest is being destroyed. Much of this forestland is being cut down to farm and raise livestock, which is then exported to the U.S. and ends up in fast-food hamburgers. According to the Rainforest Action Network, 55 square feet of tropical rainforest are destroyed to make every fast-food hamburger made from rainforest cattle. This is an area about the size of a small kitchen and it is gone forever each time one of these hamburgers is eaten. It is even worse because with each square foot of rainforest gone, up to 30 different plant species, 100 different insect species and dozens of bird, mammal and reptile species are destroyed. The rainforests are so important because half of the species on earth live in them and the forests are vital to the world’s oxygen supply.

Additional impacts on the environment from a meat-eating diet are the pollution of our water and air. All of the livestock being raised throughout the world produce enormous amounts of manure and urine, which in turn pollute natural resources. Animal waste changes the pH of our water, contaminates our air; and the gases emitted are believed to be a major cause of global warming. To keep costs down, the modern animal farming practice is to raise livestock in feedlots and factory farms where thousands or tens of thousands of animals are crowded into small spaces. However, this makes the animal waste problem worse because of concentrated waste. Livestock in the U.S. produce 2.7 trillion pounds of manure each year. That’s about ten times more waste than was produced by all the American people.

What happens to all this waste? Some farmers spray the manure on nearby fields for fertilizer, however this can be expensive, does not provide the best nutrient balance for growing plants and can spread diseases carried in the waste to humans. Some farmers use manure lagoons as a “safe” way to store millions of gallons of animal waste. These lagoons, it turns out, are not so safe. In 1995, 25 million gallons of manure and urine spilled from a hog farm lagoon into the New River in North Carolina. More than 10 million fish were immediately killed and 364,000 acres of coastal wetlands were closed to shell fishing. In the Gulf of Mexico there is a 7,000 square mile “dead zone” where there is no aquatic life due to pollution from animal waste and chemical fertilizers. The pollution from factory farms and feedlots is happening throughout the U.S., and is beginning to happen throughout the world. If we decrease our consumption of animal products we can also decrease the threat of water pollution.

The waste from factory farms gives off many harmful gases such as ammonia, methane and hydrogen sulfide, as well as clouds of dust and particles, which pollute our air. Since these farms are so large and often use huge manure lagoons the most obvious pollution is the horrible smell, which affects communities nearest the farms. The bad smell is the least of the dangers to the environment. In the U.S., animal farms are responsible for 73% of the ammonia released into the air. The ammonia can react with other gases in the air and cause respiratory problems and contribute to smog and acid rain. The particulate matter created from animal agriculture can also cause respiratory problems and can form a brown cloud effect that used to be found only near large industrialized cities.

Methane may be the most serious gas given off from livestock. In fact the meat industry is the number one source of methane throughout the world, releasing over 100 million tons a year. Methane is a gas that traps heat in the atmosphere and causes the earth’s temperature to rise. Noam Mohr in his report on global warming says, “methane is 21 times more powerful a greenhouse gas than carbon dioxide.” Theoretically by reducing the amount of meat eaten throughout the world we could slow down methane production and therefore global warming.

Yes, I am still very concerned about the mistreatment of animals, but I am also concerned with the loss of the rainforests, with the increasing threat of global warming, and with having clean water to drink and clean air to breathe. What can I, a 12-year-old American girl, do to make a difference? I will still choose to conserve water and electricity and to reuse and recycle whenever possible, but the single most environmentally important choice I can make is to eat a plant-based diet.