Changing our diet from an animal-centric diet to a plant-based diet is by far the "most green" action that an individual can take. Here are the top 10 reasons how switching can help.

1. Reduce global warming. In its 2006 report, the United Nations said raising animals for food generates more greenhouse gases than all the cars and trucks in the world combined.
2. Avoid excessive CO2 production. According to the UN Report, when emissions from land use and land use change are included, the livestock sector accounts for 9% of CO2 deriving from human-related activities, but produces a much larger share of even more harmful greenhouse gases.
3. Reduce methane/nitrous oxide production. The livestock industry accounts for respectively 37% of all human-induced methane (23 times as warming as CO2). The livestock industry also generates 65% of human-related nitrous oxide, which has 296 times the Global Warming Potential (GWP) of CO2. Most of this comes from manure.
4. Save large amounts of water. Estimates of the water required to produce a kilo of beef vary from 13,000 liters up to 100,000 liters. Whichever figure you use, the damage is plain when you consider that the water required to produce a kilo of wheat is somewhere between 1,000 to 2,000 liters.
5. Avoid further pollution of our streams, rivers and oceans. Pollution of our waterways is caused by animal waste, antibiotics and hormones entering the water cycle alongside chemicals from tanneries, fertilizers, and the pesticides used to spray feed crops. Manure, or waste water containing manure, severely harms river and stream ecosystems. Farmed animals produce about 130 times as much excrement as the entire human population of the United States. In large amounts, animal waste can present major problems to the waterways and surrounding environment.
6. Reduce destruction of topsoil and tropical rainforest. 30% of the earth's entire land surface, a massive 70% of all agricultural land, is used for rearing farmed animals. 20% of the world's grazing land has already been designated as degraded due to the rearing of animals for their meat. Livestock production is responsible for 70% of the Amazon deforestation in Latin America, where the rainforest has been cleared to create new pastures.
7. Reduce destruction of wildlife habitats and endangered species. The livestock industry is responsible for widespread deforestation and cultivation of vast tracks of land that forces millions of animals to be evicted from their homes each year, putting many species risk and causing lasting, long-term harm to our wildlife.
8. Reduce use of antibiotics, growth hormones and chemicals. USDA researchers have found that "…eating two ounces of chicken per day-the equivalent of a third to a half of a boneless breast-exposes a consumer to 3 to 5 micrograms of inorganic arsenic, the element's most toxic form." Daily exposure to low doses of arsenic can cause cancer, dementia, neurological problems, and other ailments in humans.
9. Reduce ecological footprint. By choosing vegetarianism instead of a diet loaded with animal products, individuals can dramatically reduce the amount of land, water, and oil resources that they consume and the amount of pollution they otherwise might cause.
10. Help ensure environmental sustainability. Worldwide food production requires 30% of the total soil available, 20% of fossil fuel energy and a major part of the fresh water flow. Raising cattle is one of the most damaging components of agriculture. Adopting a vegetarian diet is an important tool to achieve environmental sustainability.