Environmental impacts of animal agriculture

The environmental impact of meat production includes pollution and the use of resources such as fossil fuels, water, and land. According to a 2006 report by the Livestock, Environment And Development Initiative, the livestock industry is one of the largest contributors to environmental degradation worldwide, and modern practices of raising animals for food contributes on a "uk/environment/climate-change/meat-creates-half-of-all-greenhouse-gases-1812909.html The Independent]</ref>

Animals fed on grain need more water than grain crops.^[1] In tracking food animal production from the feed through to the dinner table, the inefficiencies of meat, milk and egg production range from a 4:1 energy input to protein output ratio up to 54:1.^[1] The result is that producing animal-based food is typically much less efficient than the harvesting of grains, vegetables, legumes, seeds and fruits for direct human consumption.^[1]

Relatedly, the production and consumption of meat and other animal products is associated with the clearing of rainforests, resource depletion, air and water pollution, land and economic inefficiency, species extinction, and other environmental harms.

Grazing and land use

Although it requires less land for the livestock, factory farming requires large quantities of feed which must be grown on large areas of land. Free-range animal production requires land for grazing, which has led to encroachment on undeveloped lands as well as clear cutting of forests. Such expansion has increased the rate of species extinction and damaged the services offered by nature, such as the natural processing of pollutants.^[2]

According to the United Nations, "Ranching-induced deforestation is one of the main causes of loss of some unique plant and animal species in the tropical rainforests of Central and South America as well as carbon release in the atmosphere."^[2] The Food and Agriculture Organization (FAO) agrees, saying that "Expanding livestock production is one of the main drivers of the destruction of tropical rain forests in Latin America, which is causing serious environmental degradation in the region."^[2] An earlier FAO study found that 90% of deforestation is caused by unsustainable agricultural practices. Logging and plantation forestry, though not as major contributors to deforestation, play a greater role in forest degradation.^[3]

|- | Beef || || 17977 || 13500 || 20700 || 16726 |- | Pork || || 5906 || 4600 || 5900 || 5469 |- | Cheese || || 5288 || || || 5288 |- | Poultry || || 2828 || 4100 || 4500 || 3809 |- | Eggs || || 4657 || 2700 || 3200 || 3519 |- | Rice || 2656 || || 1400 || 3600 || 2552 |- | Soybeans || 2300 || || 2750 || 2500 || 2517 |- | Wheat || 1150 || || 1160 || 2000 || 1437 |- | Maize || 450 || || 710 || 1900 || 1020 |- | Milk || || 865 || 790 || 560 || 738 |- | Potatoes || 160 || || 105 || || 133 |}

Producing a certain quantity of food in meat requires much more water than producing the same amount of food in grain.^[4]

According to the vegetarian author John Robbins, it roughly takes 60, 108, 168, and 229 pounds of water to produce a pound of potatoes, wheat, corn and rice respectively. He reports that a pound of beef however, requires 12,000 gallons of water.^[5]

David Pimentel explained of his calculations that:

The data we had indicated that a beef animal consumed 100 kg of hay and 4 kg of grain per 1 kg of beef produced. Using the basic rule that it takes about 1,000 liters of water to produce 1 kg of hay and grain, thus about 100,000 liters were required to produce the 1 kg of beef.

^[6]

Effects on aquatic ecosystems

Significant negative effects of aquatic and riparian ecosystems are also associated with meat production in the United States; In the Western United States 80% of stream and riparian habitats have been negatively impacted by livestock grazing. This has resulted in increased phosphates, nitrates, decreased dissolved oxygen, increased temperature, turbidity, and eutrophication events, and reduced species diversity (Belsky et al., 1999). In the Eastern United States waste release from pork farms have also been shown to cause large-scale eutrophication of bodies of water, including the Mississippi River and Atlantic Ocean (Palmquist, et al., 1997).

Fossil fuel consumption and greenhouse gas emissions

Farmer ploughing rice paddy, in Indonesia. Animals can provide a useful source of draught power to farmers in the developing world

At a global scale, a 29 November 2006 United Nations report called the Livestock's Long Shadow - Environmental Issues and Options assesses the meat and livestock industry to contribute to about 9% of total anthropogenic carbon dioxide emissions, including 37% of methane and 65% of nitrous oxide emissions.

At a local level, livestock represents up to half of New Zealand's greenhouse gas emissions,^[7] and nearly 20% of the total methane emissions of the United States of America.^[8]

Indirect effects account for most of agricultural greenhouse gas emissions, and are attributed to emissions of nitrous oxides and other gases from concentrated livestock operations and from microbial activities in soil and water following applications of fertilizers .^[9] Greenhouse gas emissions are not limited to animal husbandry; for instance, in many countries where rice is the main cereal crop, rice cultivation is responsible for most of the methane emissions.^[10]

The production of protein from grain-fed animals requires eight times as much fossil-fuel energy as the production of plant protein.^[1] According to an article in Environmental Health Perspectives, typical feedlot husbandry of cattle requires an input of 35 kcal of fossil fuel to produce one kcal of food energy in beef, far more than that required for comparable plants.^[11]

A 2006 study at the University of Chicago concluded that a person switching from a typical American diet to a vegan diet with the same number of calories would prevent the emission of 1485 kg of carbon dioxide. The difference exceeds that of an individual switching from a Toyota Camry to the hybrid Toyota Prius, and collectively amounts to over 6% of the total U.S. greenhouse gas emissions.^[12]

This view, however, reflects the situation in the developed world and does not take into account the situation in most third world countries. In the developing world, notably Asia and Africa, fossil fuels are seldom used to transport feed for farm animals. Sheep or goats, for example, require no fuel, since they graze on farmlands, while bales of hay for bovines are still transported mainly using bullock carts or similar devices. Little to no meat processing takes place in the vast majority of the developing world. Animals are also often herded to the place of slaughter (with the exception of poultry) resulting in a very low use of fossil fuels.^[13] In fact, farm animals in the developing world are used for multiple purposes, from providing draught power to transportation, while also serving as meat once they reach the end of their economic lives.

A more efficient use of animal waste may be a contributing factor in sustainability. The by-products of slaughtered animals can be used to provide biogas. Trains running on this fuel are already in operation in Sweden.^[14] The use of biogas to run mass transit is likely only possible as a side effect of industrial agriculture.

Response

The detrimental environmental effects of meat production has become a strong argument in favour of the reduction or abandonment of the consumption of meat, most notably for vegetarianism. Individual commitment is being increasingly supported by local initiatives, such as the meat-free days of the Belgian city of Ghent (or Veggiedag)^[15] which imposes vegetarian-only food in public canteens for civil servants and elected concillors, soon in all schools, and promotes vegetarian eating options in town through the distribution of "veggie street maps".

The UN has admitted a report linking livestock to global warming exaggerated the impact of eating meat on climate change. Dr Frank Mitloehner, from the University of California at Davis (UCD), said meat and milk production generates less greenhouse gas than most environmentalists claim and that the emissions figures were calculated differently to the transport figures, resulting in an “apples-and-oranges analogy that truly confused the issue”. ^[16] The meat figure had been reached by adding all greenhouse-gas emissions associated with meat production, including fertilizer production, land clearance, methane emissions and vehicle use on farms, whereas the transport figure had only included the burning of fossil fuels. In the original press release in which Dr. Mitloehner's assertions appear, it transpires that his work was funded by a $26,000 grant from the Beef Checkoff Program.^[17] In addition, his comments do not state that the UN's calculations are false, but rather that they considered the entire commodity chain, which they did not do for transport.^[18]

References

^ ^a ^b ^c ^d U.S. could feed 800 million people with grain that livestock eat
^ ^a ^b ^c FAO - Cattle ranching is encroaching on forests in Latin America
^ World Rainforest Movement - What are underlying causes of deforestation?
^ http://www.waterfootprint.org/Reports/Report12.pdf report12.pdf
^ Robbins, John. The Food Revolution. Conari Pr; 1 edition. July 11, 2001. ISBN 1573247022
^ "U.S. could feed 800 million people with grain that livestock eat, Cornell ecologist advises animal scientists." Pimentel, David. Cornell News Service [1]
^ New Zealand Ministry of Agriculture and Forestry - Voluntary Greenhouse Gas Reporting Feasibility Study - Summary
^ "Methane: Sources and Emissions". http://www.epa.gov/. United States Environmental Protection Agency. Retrieved 2007-11-26. {{cite web}}: External link in |work= (help)
^ This reference link is defunct, please visit the Global Change Program Office of the Office of the Chief Economist to find its new location.
^ Methane Emission from Rice Fields - Wetland rice fields may make a major contribution to global warming by Heinz-Ulrich Neue
^ Leo Horrigan, Robert S. Lawrence, and Polly Walker. "How Sustainable Agriculture Can Address the Environmental and Human Health Harms of Industrial Agriculture." Environmental Health Perspectives Volume 110, Number 5, May 2002.
^ Gidon Eshel and Pamela A. Martin. "Diet, Energy, and Global Warming." Earth Interactions, Volume 10 (2006), Paper No. 9.
^ Food for all - World food summit - Agricultural machinery worldwide
^ "Cows make fuel for biogas train". BBC News. 2005-10-24. Retrieved 2010-05-02.
^ "Belgian city plans 'veggie' days" on BBCNews (2009-05-12).
^ Jamieson, Alastair (2010-03-24). "UN admits flaw in report on meat and climate change". The Daily Telegraph. London.
^ http://www.outlookseries.com/N6/Science/2850_Frank_Mitloehner_UC_Davis_Cows_Not_Blame_Climate_Change_Frank_Mitloehner.htm
^ http://ubash.org/blog/2010/03/26/reading-past-the-headlines-is-meat-still-an-environmental-issue/