Livestock - Environmental Impact

Environmental Impact

See also: Environmental effects of meat production

At first reports like the United Nations report "Livestock's Long Shadow" cast a pall over the livestock sector (primarily cattle, chickens, and pigs) for 'emerging as one of the top two or three most significant contributors to our most serious environmental problems.' In April 2008, the United States Environmental Protection Agency released a major stocktake of emissions in the United States entitled Inventory of U.S. Greenhouse Gas Emissions and Sinks: 1990-2006. On 6.1 it found "In 2006, the agricultural sector was responsible for emissions of 454.1 teragrams of CO₂ equivalent (Tg CO₂ Eq.), or 6 percent of total U.S. greenhouse gas emissions." By way of comparison, transportation in the US produces more than 25% of all emissions. In 2009, Worldwatch Institute released a report which revealed 51% of Greenhouse Gas emissions were from the animal agriculture sector.

The issue of livestock as a major policy focus remains, especially when dealing with problems of deforestation in neotropical areas, land degradation, climate change and air pollution, water shortage and water pollution, and loss of biodiversity. A research team at Obihiro University of Agriculture and Veterinary Medicine in Hokkaidō found that supplementing the animals' diet with cysteine, a type of amino acid, and nitrate can reduce the methane gas produced, without jeopardising the cattle's productivity or the quality of their meat and milk.

Deforestation Deforestation impacts the carbon cycle (and global and regional climate) and causes habitat loss of many species. Forests that are sinks for the carbon cycle are lost through deforestation. Forests are either logged or burned to make room for grasslands, often the area needed is extensive. Deforestation can also create fragmentation, allowing only patches of habitat for species to live. If patches are distant and small, gene flow is reduced, habitat is altered, edge effects will occur and there will be more opportunities for invasive species to intrude.

Land Degradation Research from the University of Botswana in 2008 has found that farmers' common practice of overstocking cattle to cope with drought losses made ecosystems more vulnerable and risked long term damage to cattle herds, in turn, by actually depleting scarce biomass. The study of the Kgatleng district of Botswana predicted that by 2050, the cycle of mild drought is likely to become shorter for the region (18 months instead of two years) due to climate change.

Climate Change & Air Pollution Methane is one of the gasses emitted from livestock manure; it persists for long periods of time and is a green house gas. It is the second most abundant green house gas after carbon dioxide. Even though there is less methane then carbon dioxide its ability to warm the atmosphere is 25 times greater.

Water Shortage Livestock require water for consumption but also for watering drops necessary for feed. Grains are often used to feed live stock about 50% of US grains produced does and 40% of world grains produced does as well. Grain and in general crop production requires various amounts of water, it takes 100,000 liters of water for a kilogram of grain fed beef, compared to wheat, which takes 900 liters.

Water Pollution Fertilizers that often contain manure are used to grow such crops (as cereal and fodder) that have phosphorus and nitrogen in them, 95% of which is estimated to be lost to the environment. The pollutants then cause dead zones for plants and aquatic animals due to the lack of oxygen in the water. The lack of oxygen is known as eutrophication, where organisms present in the water grow excessively and then later decompose using up the oxygen in the water. The most prominent example of such is the Gulf of Mexico, where much of the nutrients in fertilizer used in the mid west are funneled down the Mississippi River into the Gulf causing massive dead zones. Another pollutant not most commonly though of is antibiotics and hormones. In southern Asia vultures that consumed carcasses of livestock declined 95% due to antibiotic known as Diclofenac.

Alternatives Researchers in Australia are looking into the possibility of reducing methane from cattle and sheep by introducing digestive bacteria from kangaroo intestines into livestock.

In semi arid rangelands such as the Great Plains in the U.S., there has been research that provides evidence that livestock can be beneficial to maintaining grassland habitats. Livestock create and maintain habitat for big game species