Environmental Vegetarianism - Environmental Impact of Meat Production

Environmental Impact of Meat Production

Industrial monoculture is harvesting large quantities of a single food species, such as maize, or cattle. Monoculture is commonly practiced in industrial agriculture, which is more environmentally damaging than sustainable farming practices such as organic farming, permaculture, arable, pastoral, and rain-fed agriculture.

According to a 2006 Food and Agriculture Organization report, industrialized agriculture contributes on a “massive scale” to climate change, air pollution, land degradation, energy use, deforestation, and biodiversity decline. The FAO report estimates that the livestock (including poultry) sector (which provides draft animal power, leather, wool, milk, eggs, fertilizer, pharmaceuticals, etc., in addition to meat) contributes about 18 percent of global GHG (greenhouse gas) emissions expressed as 100-year CO₂ equivalents. This estimate was based on life cycle analysis, including feed production, land use changes, etc., and used GWP (global warming potential) of 23 for methane and 296 for nitrous oxide, to convert emissions of these gases to 100-year CO₂ equivalents. Some sources disagree with some of the figures used in arriving at the FAO estimate of 18 percent. For example, the FAO report estimates that 37 percent of global anthropogenic methane emissions are attributable to the livestock sector, and a US NASA summary indicates about 30 percent. Because of the GWP multiplier used, such a difference between estimates will have a large effect on an estimate of GHG CO₂ equivalents contributed by the livestock sector. Livestock sources (including enteric fermentation and manure) account for about 3.1 percent of US anthropogenic GHG emissions expressed as CO₂ equivalents. This estimate is based on methodologies agreed to by the Conference of Parties of the UN FCCC. Data of a USDA study indicate that about 0.9 percent of energy use in the United States is accounted for by raising food-producing livestock and poultry. In this context, energy use includes energy from fossil, nuclear, hydroelectric, biomass, geothermal, technological solar, and wind sources. The estimated energy use in agricultural production includes embodied energy in purchased inputs.

Another agricultural effect is on land degradation. Much of the world's crops is used to feed animals. With 30 percent of the earth's land devoted to raising livestock, a major cutback is needed to keep up with growing population. A 2010 UN report explained that Western dietary preferences for meat would be unsustainable as the world population rose to the forecasted 9.1 billion by 2050. Demand for meat is expected to double by this date; meat consumption is steadily rising in countries such as China that once followed more sustainable, vegetable-based diets. Cattle are a known cause for soil erosion through trampling of the ground and overgrazing.

The environmental impacts of animal production vary with the method of production. A grazing-based production can limit soil erosion and also allow farmers to control pest problems with less pesticides through rotating crops with grass. In arid areas, however, it may catalyze a desertification process. The ability of soil to absorb water by infiltration is important for minimizing runoff and soil erosion. Researchers in Iowa reported that a soil under perennial pasture grasses grazed by livestock was able to absorb far more water than the same kind of soil under two annual crops: corn and soybeans. Corn and soybean crops commonly provide food for human consumption, biofuels, livestock feed, or some combination of these.

The FAO initiative concluded that "the livestock sector emerges as one of the top two or three most significant contributors to the most serious environmental problems, at every scale from local to global."