If you want to dramatically reduce your carbon footprint, you might want to start with your dinner plate. A new study published in the Proceedings of the National Academy of Sciences revealed that cattle are the top emitters of greenhouse gasses among livestock. The research, backed by the International Livestock Research Institute (ILRI) and the Commonwealth Scientific and Industrial Research Organization (CSIRO) found that among small ruminants, poultry, pigs, and cattle were responsible for more than three-quarters of livestock emissions.
As reported by BBC News, each year the world produces 58 million tons of beef, 586 million tons of milk, and 124 million tons of poultry. As developing nations become more carnivorous, there is great concern that eating higher on the food chain will become increasingly unsustainable. According to the UN World Health Organization, one hectare of earth can feed 22 people when planted with potatoes as compared to 19 for rice, and only one or two individuals when supporting sheep or cows.
The study looked at farm animals from 28 regions across the world. They compiled data to determine how efficiently feedstock was converted in to milk, meat, and eggs and the overall greenhouse gasses released as byproducts. While the efficiency ratio of feed to meat, milk, or eggs are not uniform across nations, it takes a proportionally large amount of grain to maintain livestock like cows, sheep, chickens, or goats. The study noted that it takes 1.3 billion tons of grain in North America, Europe, Eastern China and Latin America to raise mostly pigs and poultry into maturity. In sub-Saharan Africa, these animals require 50 million tons of grain.
Latin America, South Asia, Europe, and sub-Saharan Africa were calculated to have the highest regional greenhouse gas totals. Ruminant animals like cows, sheep, and goats were the most energy intensive and damaging to the environment, needing five times more food to produce a kilogram of protein in the form of meat than in the form of milk. With many regions of the world rapidly ubanizing, solutions to climate change will come from adjustments individual diets as well as transportation and energy generation.
Via BBC News