There are surprisingly large hidden costs to hot dogs, burgers, milk, and other animal products, finds a new report entitled Livestock’s Long Shadow. Prepared by the United Nations Food and Agricultural Organization in Rome, the report notes that animal agriculture is the second or third biggest contributor to "the most serious environmental problems, at every scale from local to global."
The report's authors calculate that livestock production taps 8 percent of all fresh water used by humanity, primarily to irrigate feed crops. Farmed animals—now 20 percent of the total mass of land animals—are also edging out species and cutting biodiversity. The report observes that 30 percent of the land that these livestock now occupy once nurtured wildlife.
Livestock production is also having a growing influence on climate. Animal farming accounts for 18 percent of greenhouse-gas emissions, making it a bigger contributor than transportation. For instance