Understanding the environmental impact of the livestock industry is actually quite simple. It comes down to the fact that for every human on the planet, there are a little over 3 animals in the livestock industry that need to (a) eat (b) breathe and digest food (c) excrete food consumed. Examining the environmental impact of these 3 basic activities explains almost entirely the extreme environmental destruction caused by the livestock industry.
The bulk of the impact of the livestock sector, comes from having to produce food for 24 bn animals, who are kept alive artificially for human consumption.
Consider the following1
- Every year 760 mn tons of grains are produced to be fed to animals in intensive factory farms globally.
- The production of this feedstock takes up 0.5 bn hectares of land (33% of total agricultural cropland) and 32% of global usable freshwater resources.
- Apart from feedstock produced for animals fed in factory farms, an additional 3.4 bn hectares of land (26% of the ice free terrestrial surface of the planet) is consumed for grazing by livestock.
- The emissions emanating from the growing, processing and transportation of this feedstock is estimated at 2.9 bn units of Co2 equivalent – accounting for 33% of emissions contributed by the livestock industry or 6.6% of all human caused emissions
- To make available the land required for grazing and animal feedstock growing, our forests are rapidly getting cleared -- 70% of previous forested land in the Amazon is occupied by pastures, and feedcrops cover a large part of the remainder.
- 73% of rangelands in dry areas, have been degraded to some extent, mostly through overgrazing, compaction and erosion created by livestock action.
- The Livestock industry accounts for 32-33% of all nitrogen and phosphorous found in freshwater globally. Usage of fertilisers in agriculture, leads to water getting contaminated with nitrogen and phosphorous. With 70% of agricultural land being used to grow animal feedstock, the livestock industry is the principal cause of water pollution through fertilisers.
Respiratory & digestive processes of animals
Both the respiratory and digestive process of 24 bn animals contribute to significant emissions. Of particular importance is the digestive process of ruminants (cows, buffaloes and goats), who emit large amounts of methane during digestion.
Methane is particularly damaging from an emissions perspective, with 23 times the global warming potential (GWP) of Co2. In all, the respiratory and digestive process of livestock contribute 1.9 bn tons of carbon equivalent (accounting for 24% of emissions of the livestock industry and 4.3% of all human caused global emissions)1
Disposal of animal waste is a concern, as it is often managed poorly even in large scale industrial farms. In 2007, US livestock generated about 500 mn tons of manure, 3 times the amount of human waste produced by all of the US population2. Consider the following:
- Animal waste releases nitrous oxide and methane, polluting the air and waterways. More than 34,000 miles of rivers and 216,000 acres of lakes in the US have been degraded by waste from confined feeding operations2. As per the Indian Ministry of Environment and Forests, the livestock industry contributes to the contamination of an estimated 70 percent of India's surface water and an increasing percentage of its groundwater3.
- Animal manure (urine and faeces) emit gases such as methane, nitrous oxide, ammonia and carbon dioxide. Methane, nitrous oxide and ammonia are particularly damaging greenhouse gases, with significantly higher GWPs than Co2 (23x for methane and 296x for nitrous oxide) as well as being a key factor behind the acidification of our ecosystems & acid rain (ammonia). Animal manure is estimated to account for 2.2 bn units of Co2 equivalent (accounting for 28% of emissions of the livestock industry and 5% of all human caused global emissions)1
1- UN FAO, Livestocks Long Shadow
2 - US Environment Protection Agency
3 - 2009 Annual Report, Ministry of Environment & Forests India