Livestock production contributes 40 percent to the world's agricultural gross domestic product, provides income for more than 1.3 billion people and represents 17 percent of global caloric intake per person per day and 33 percent of all protein in human diets.
Production at this grand of a scale does come at a price, though, as livestock are responsible for an estimated 8 to 18 percent of the Earth's greenhouse gases (GHG). The finger often gets pointed at modern agricultural practices, but a recent study found that current livestock production in developed countries released less GHG for every pound of food produced.
Scientists from Kenya, Australia and Austria compared the amount of feed livestock consume to produce a pound of protein, or "feed efficiency," to the amount of greenhouse gases released for every pound of protein produced, called "emission intensity."
The study found that, of all livestock species, beef and dairy cattle are the biggest source of greenhouse gas emissions globally, accounting for 77 percent of the total. Pork and poultry account for only 10 percent of emissions.
In terms of emission intensity, it was discovered that animals in many parts of the developing world require far more food to produce 1 pound of protein than animals in more modern, developed countries. For example, cattle grazing in arid countries like Ethiopia, Somalia and Sudan can release the equivalent of 1,000 pounds of carbon for every pound of protein they produce. Conversely, in many parts of the U.S. and Europe, the emissions discharged is just 10 pounds of carbon per pound of protein.
The full report can be found here.
