Animal agriculture takes a devastating toll on the earth.
It is an inefficient way of producing food, since feed for farm animals requires land, water, fertilizer, and other resources that could otherwise have been used directly for producing human food. In a time when population pressures have become an increasing stress on the environment, there are additional arguments for a vegan diet. The United Nations has reported that a vegan diet can feed many more people than an animal-based diet. For instance, projections have estimated that the 1992 food supply could have fed about 6.3 billion people on a purely vegetarian diet, 4.2 billion people on a 85% vegetarian diet, or 3.2 billion people on a 75% vegetarian diet. According to a United Nations study, animal agriculture is the third largest contributor to green house emissions, which means that it is more than the entire transport system of the world. Says Henning Steinfeld, Chief of FAO’s Livestock Information and Policy Branch and senior author of the report:
Livestock are one of the most significant contributors to today’s most serious environmental problems. Urgent action is required to remedy the situation.
When emissions from land use and land use change are included, the livestock sector accounts for 9 percent of CO2 deriving from human-related activities, but produces a much larger share of even more harmful greenhouse gases. It generates 65 percent of human-related nitrous oxide, which has 296 times the Global Warming Potential (GWP) of CO2. Most of this comes from manure. And it accounts for respectively 37 percent of all human-induced methane (23 times as warming as CO2), which is largely produced by the digestive system of ruminants, and 64 percent of ammonia, which contributes significantly to acid rain.
The sheer quantity of animals being raised for human consumption also poses a threat of the Earth’s biodiversity. Livestock account for about 20 percent of the total terrestrial animal biomass, and the land area they now occupy was once habitat for wildlife. In 306 of the 825 terrestrial eco-regions identified by the Worldwide Fund for Nature, livestock are identified as “a current threat”, while 23 of Conservation International’s 35 “global hotspots for biodiversity” – characterized by serious levels of habitat loss – are affected by livestock production.
The livestock sector provides food and income for one billion of the world’s poorest people. This is an argument that many use to show the good side of animal agriculture; however animal agriculture is undergoing a fundamental shift. Production is moving from the countryside to urban and peri-urban areas, and towards sources of animal feed, whether feed crop areas or transport and trade hubs where feed is distributed. Today, an estimated 80 percent of growth in the livestock sector comes from industrial production systems. Owing to those shifts, the report says, livestock are entering into direct competition for scarce land, water and other natural resources with some of the world’s poorest people. 75% of South African cattle spend a third of their lives in feedlots, fed by grains grown on the country’s scarce arable lands.