Agriculture and the Environment

Agriculture is thought by many to cause a number of different environmental problems:

• it can cause a decrease in biodiversity and the consolidation of diverse biomass into a few species
• it changes natural environments
• it can create a surplus of nitrogen and phosphorus in rivers and lakes
• the creation of arable land causes the destruction of natural ecosystems
• it produces harmful by-products
• it can cause soil erosion, deforestation, and the depletion of minerals in the soil
• the herbicides, fungicides, insecticides, and other biocides used in agriculture can be damaging
• particulate matter, including ammonia and ammonium off-gassing from animal waste may contribute to air pollution, as can farm equipment and transportation powered by fossil fuels

According to the United Nations, the livestock sector (primarily cows, chickens, and pigs) is one of the top two or three most significant contributors to our most serious environmental problems. Livestock production occupies 70% of all land used for agriculture, or 30% of the land surface of the planet. It is one of the largest sources of greenhouse gases: 18% of the world's greenhouse gas emissions as measured in CO2 equivalents. By comparison, all transportation emits 13.5% of the CO2.

Livestock production also produces 65% of human-related nitrous oxide (which has 296 times the global warming potential of CO2) and 37% of all human-induced methane (which is 23 times as warming as CO2). It also generates 64% of the ammonia, which contributes to acid rain and acidification of ecosystems.