Raising enormous numbers of land animals for food—67.5 billion globally in 2008—causes significant emissions of three of the most important climate-changing gases, disrupting weather, temperature, and ecosystem health.

Animal agriculture generates approximately 18 percent of human-induced greenhouse gas emissions worldwide, according to a 2006 report by the Food and Agriculture Organization (FAO) of the United Nations, including about 37 percent of global methane emissions and 65 percent of nitrous oxide emissions, which have over 20 and 300 times the global warming power of carbon dioxide, respectively.

Practically every stage of meat, egg, and dairy production contributes to the climate crisis by releasing greenhouse gases into the atmosphere.

HSI promotes transition away from industrial farm animal production to more sustainable—and welfare-friendly—forms of agriculture, as well as a reduction in the number of animals raised for food. You can help by adopting a diet that is more friendly to animals and the environment.