Global warming poses one of the most serious threats to the global environment ever faced in human history. Yet by focusing entirely on carbon dioxide emissions, major environmental organizations have failed to account for published data showing that other gases are the main culprits behind the global warming we see today. As a result, they are overlooking the fact that the single most important step an individual can take to reduce global warming [faster than any other means] is to adopt a vegetarian diet.1
In its 2006 report, the United Nations said raising animals for food generates more greenhouse gases than all the cars and trucks in the world combined.2
According to the UN Report, when emissions from land use and land use change are included, the livestock sector accounts for 9 per cent of CO2 deriving from human-related activities, but produces a much larger share of even more harmful greenhouse gases.3
Cows and sheep are responsible for 37% of the total methane (23 times as warming as CO2) generated by human activity.4 With methane emissions causing nearly half of the planet’s human-induced warming, methane reduction must be a priority
The livestock industry generates 64 per cent of ammonia, which contributes significantly to acid rain.5
The livestock industry also generates 65 per cent of human-related nitrous oxide, which has 300 times the Global Warming Potential (GWP) of CO2. Most of this comes from manure.6
In addition to having the advantage of immediately reducing global warming, shifting away from methane-emitting food sources is much easier than cutting carbon dioxide7:
First, greenhouse gas reductions through a vegetarian diet are limitless. In principle, even 100% reduction could be achieved with little negative impact. In contrast, similar cuts in carbon dioxide are impossible without devastating effects on the economy. Even the most ambitious carbon dioxide reduction strategies fall short of cutting emissions by half.
Second, a shift in diet can lower greenhouse gas emissions much more quickly than shifts away from the fossil fuel burning technologies that emit carbon dioxide. The turnover rate for most ruminant farm animals is one or two years, which means that decreases in meat consumption would result in an almost immediate drop in methane emissions. The turnover rate for cars and power plants, on the other hand, can be decades. Even if cheap, zero-emission fuel sources were available today, they would take many years to build and slowly replace the massive infrastructure our economy depends upon today.
Similarly, unlike carbon dioxide which can remain in the air for more than a century, methane cycles out of the atmosphere in just eight years. Therefore, lower methane emissions translate to cooling of the earth quickly.
Estimates of the water required to produce a kilo of beef vary, from 13,000 liters8 up to 100,000 liters9 . Whichever figure you use, the damage is plain when you consider that the water required to produce a kilo of wheat is somewhere between 1,000-2,000 litres.
Avoid further pollution of our streams/rivers/oceans
Pollution of our waterways is caused by animal waste, antibiotics and hormones entering the water cycle alongside chemicals from tanneries, fertilizers, and the pesticides used to spray feed crops.
Manure, or waste water containing manure, severely harms river and stream ecosystems. Farmed animals produce about 130 times as much excrement as the entire human population of the United States. Since factory farms don't have sewage treatment systems as our cities and towns do, this concentrated slop ends up polluting our water, destroying our topsoil, and contaminating our air.10
Once factory farm pollutants—including nitrogen, phosphorus, antibiotics and pesticides—reach the waterways they cause a great deal of damage to aquatic and human life. Algal blooms are a particular problem, blocking waterways, using up oxygen as they decompose, and killing the natural populations of fish.11
• In large amounts, animal waste can present major problems to the waterways and their surrounding environment. More than 2 billion tons of animal manure was produced worldwide during the late 1990s. Assuming average nitrogen content of around 5%, this makes 100 million tons of nitrogen12 finding its way into our water system.
Reduce destruction of topsoil & tropical rainforest
Thirty percent of the earth’s entire land surface—a massive 70% of all agricultural land—is used for rearing farmed animals. Much of this is grazing land that otherwise would host natural habitats such as valuable rainforests. And, of the entire world’s land suitable for growing crops that would otherwise directly feed humans, a third of it is used to produce feed for farmed animals.13
Livestock farming can lead to overgrazing causing soil erosion, desertification and deforestation14. Twenty percent of the world’s grazing land has already been designated as degraded due to the rearing of animals for their meat.15
Livestock production is responsible for 70% of deforestation in the Amazon region of Latin America, where rainforests are being cleared to create new pastures.16
Deforestation increases greenhouse gas emissions by releasing carbon previously stored in the trees. It is also a major driver in the loss of biodiversity – a pressing concern when one considers the fact that just a few species of livestock now account for about 20% of total terrestrial animal biomass.17
Reduce destruction of wildlife habitats & endangered species
The livestock industry is responsible for widespread deforestation and cultivation of vast tracks of land. Wide-spread cultivation of the land ruins animals’ natural habitat and forces millions of them to be evicted from their homes each year, causing long-term harm to our wildlife.
Reduce use of antibiotics, growth hormones, and chemicals
Farmed animals and fish are fed a wide variety of drugs to fatten them faster and to keep them alive in conditions that would otherwise kill them. These drugs enter the human food chain through direct consumption or through pollution of our waterways.
The effect on humans of consuming low levels of these drugs during a lifetime is unknown but could be serious. Antibiotics given to farmed animals include penicillin, erythromycin, and inorganic arsenic (the most toxic form of arsenic).
Antibiotics contain significant amounts of the most carcinogenic form of arsenic. USDA researchers have found that “…eating two ounces of chicken per day—the equivalent of a third to a half of a boneless breast—exposes a consumer to 3 to 5 micrograms of inorganic arsenic, the element’s most toxic form.” Daily exposure to low doses of arsenic can cause cancer, dementia, neurological problems, and other ailments in humans. 18
Antibiotics reduce the amount of bacteria in animals' intestines and preventing infection, to which crowded, stressed animals are predisposed. Routine antibiotic use leads to antibiotic-resistant bacteria, thereby reducing antibiotics’ effectiveness when treating people suffering from food poisoning or other infectious diseases. 19
Farmers give hormones to animals to increase growth and productivity. Widely used in the United States, these hormones are known to cause several types of cancer and reproductive dysfunction in humans.20 While U.S. farmers claim that using hormones to promote growth is safe, the European Union has prohibited this practice since 1995.21
Fish farming contributes directly to the pollution of our waterways:
Large numbers of fish kept long-term in a single location produces a significant amount of feces concentrated in a small location, which can enter local waterways.
Because of parasite problems, some aquaculture operators frequently use strong antibiotic drugs to keep the fish alive. Many fish still die prematurely at rates of up to 30%.22 The residual presence of these drugs in human food products has become controversial because the use of antibiotics in food production is thought to increase the prevalence of antibiotic resistance in human diseases.
These drugs enter the food chain through direct consumption of the farmed fish itself and through the highly concentrated feces deposits that contaminate water supplies. Reports indicate that Scottish salmon farms alone have breached pollution limits more than 400 times in the past 3 years.23
By choosing a vegetarian diet instead of one loaded with animal products, individuals can dramatically reduce the amount of land, water, and oil resources that they consume and the amount of pollution they otherwise might cause. Of course, reducing one’s ecological footprint should also mean causing less harm to the Earth's non-human inhabitants. By switching to a vegetarian diet, each person can save more than 100 animals each year from the horrific cruelty of the meat industry24.
There were approximately 6.5 billion people living on earth in 20052526 , and as the world’s population continues to grow, our requirement for food will also increase. Worldwide food production requires 30% of the total soil available, 20% of fossil fuel energy and a major part of the fresh water flow27. Raising cattle is one of the most damaging components of agriculture28. In addition to their gaseous emissions and manure products, it causes the most environmental damage of any non-human species through over-grazing, soil erosion, desertification and tropical deforestation. Studies on world food security estimate that an affluent diet containing meat requires up to 3 times as many resources as a vegetarian diet29.
Global production of meat has increased dramatically from 130 million tones in the late 1970s to 230 million tones in the year 200030. Meat is now the single largest source of animal protein in all affluent nations31 and demand for animal flesh is expected to more than double by the year 205032. In order to meet this growing appetite, animals will no doubt be reared more intensively and cheaply with factory farming and aquaculture (fish farming) causing further pollution, water demand and land usage. If nothing is done, the environmental impact of meat production can only increase.
Adopting a vegetarian diet is an important tool to achieve environmental sustainability.
“EarthSave Report: A New Global Warming Strategy: How Environmentalists are Overlooking Vegetarianism as the Most Effective Tool Against Climate Change in Our Lifetimes,” Noam Mohr, Aug. 2005: http://earthsave.org/globalwarming.htm
Pimental, D., Houser, J., Preiss, E., White, O., Fang, O., Mesnick, L., Barsky, T., Tariche, J.S. and Alpert, S. 1997. Water Resources: Agriculture, the Environment, and Society. Bioscience. 47 (2), 97-106.
Smil, V. 2002. Worldwide transformation of diets, burdens of meat production and opportunities for novel food proteins. Enzyme and Microbial Technology. 30, 305-311.
National Research Council, The Use of Drugs in Food Animals: Benefits and Risks (Washington, DC: National Academy Press, 1999); John S. Spika et al., "Chloramphenicol-Resistant Salmonella Newport Traced through Hamburgers to Dairy Farms," New England Journal of Medicine 316 (1987): 565-570; Richard S. Schwalbe et al., "Isolation of Vancomycin-Resistant Enterococci from Animal Feed in USA," The Lancet 353 (1999): 722.
Nonhebel. S. 2004. On resource use in food production systems: the value of livestock as ‘rest-stream upgrading system’. Ecological Economics. 48, 221-230.
Goodland, R. 1997. Environmental sustainability in agriculture: diet matters. Ecological Economics. 23, 189-200.
Penning de Vries, F.W.T., Van Keulen, H. and Rabbinge, R. 1995. Natural resources and limits of food production in 2040. Eco-Regional Approaches for Sustainable Land Use and Food Production. Kluwer Academic Publishing. Dordrecht. 65-87: http://ageconsearch.umn.edu/bitstream/123456789/19695/1/br18.pdf
National Research Council. Nutrient Requirements of Poultry. Washington, DC: National Academy Press, 1994.
Smil, V. 2002. Worldwide transformation of diets, burdens of meat production and opportunities for novel food proteins. Enzyme and Microbial Technology. 30, 305-311.