Whats animal agriculture's effect on the environment?
Animal agriculture has a significant and negative impact on the environment. The main impacts fall are 1. animal agriculture uses a lot of land, 2. greenhouse gas emissions from animal agriculture are higher than most realize and 3. the animal agriculture industry uses a lot of water.
- Raising both the livestock and the crops needed to feed that livestock takes up a lot of space. The United Nation's Food and Agriculture Organization (FAO) estimates that of our ice-free land, 26% of it is used to graze livestock and 33% of it grows feed for livestock (source).
- Animal agriculture is responsible for 13-18% of greenhouse gases (GRG) globally although some argue we are underestimating whereas others believe we are not.
Methane is released when cows and other ruminants burp, and this GHG lasts much longer in the atmosphere than carbon dioxide. The GHG emissions tied to animal agriculture is also related to the amount of land used in this industry. Whenever land is converted from forests, which are carbon dioxide sinks, this process of removing the GHG from the atmosphere is replaced with less biomass and therefore a less effective CO2 removal method.
- Animal agriculture uses a lot of water, as shown below for the United States for the year 2010.
Water is needed for the animals themselves but it is also needed to grow all of their feed. Beef has a particularly large impact: it takes 15,415 liters of water per kilogram of beef. If you look at the impact of a human and a dairy cow at the end of both of their lifespans, the dairy cow has a larger impact on water despite a much shorter lifespan (source)
Animal agriculture also has many of the problems agriculture has, and you can read about those here.