section_path: Impact of cattle husbandry/On the environment
section_name: On the environment
paragraph_text: On the environment
  
  The gut flora of cattle produce methane, a powerful greenhouse gas, as a byproduct of enteric fermentation, with each cow belching out 100kg a year. Additional methane is produced by anaerobic fermentation of stored manure. The FAO estimates that in 2015 around 7% of global greenhouse gas emissions were due to cattle, but this is uncertain. Reducing methane emissions quickly helps limit climate change.
  
  Concentrated animal feeding operations in particular produce substantial amounts of wastewater and manure, which can cause environmental harms such as soil erosion, human and animal exposure to toxic chemicals, development of antibiotic resistant bacteria and an increase in E. coli contamination.
  
  In many world regions, overgrazing by cattle has reduced biodiversity of the grazed plants and of animals at different trophic levels in the ecosystem. A well documented consequence of overgrazing is woody plant encroachment in rangelands, which significantly reduces the carrying capacity of the land over time.