The information on the environmental impact of meat was compiled by Hannah Kohrman. October 2012
People who eat less red meat have a lower risk of heart disease, diabetes, and colorectal cancer. But cutting back would also be gentler on the planet. Here's some of the damage done to the Earth by the way we raise and feed livestock.
Substituting chicken, fish, or eggs for red meat and dairy just one day a week for a year would reduce greenhouse gas emissions by an amount equivalent to not driving 760 miles. Going completely vegetarian one day a week for a year is equivalent to not driving 1,160 miles.
Source: Environ. Sci. Technol. 42: 3508, 2008.
A dead zone is an area in a body of water where there isn’t enough oxygen to support life because of excessive nutrient runoff, often from fertilizer and manure. In the United States, the production of livestock and their feed crops is responsible for one-third of the nitrogen and phosphorous discharged into freshwater. In 2011, the dead zone at the mouth of the Mississippi River (in red) was larger than the state of Connecticut.
Meat & Health
People who eat the most red meat (typically two servings a day) have a 40 percent higher risk of dying of heart attack, stroke, or other cardiovascular disease than those who consume the least (typically one serving every two to four days).¹ Those who eat the most meat also have a higher risk of colorectal cancer and diabetes.²³ Researchers know that the saturated fat and cholesterol in red meat boost the risk of heart attacks. But they aren't sure how meat may raise the risk of cancer and diabetes. One possibility: meat's heme iron may combine with protein and nitrites or nitrates in food to create carcinogenic N-nitroso compounds in the gut. Heme iron may also damage insulin-making cells in the pancreas.
1 Arch. Intern. Med. 172: 555, 2012.
2 PLoS ONE. DOI:10.1371/journal.pone.0020456.
3 Am. J. Clin. Nutr. 94: 1088, 2011.
For every kilogram (roughly two pounds) of beef we eat, 27 kilograms of greenhouse gasses are released into the environment. That includes gasses that come from growing the animal feed and from the manure and methane emissions that beef cattle produce.
Where The Water Falls
A food's water footprint is the number of liters of water it takes to produce one kilogram of the food. For animals, it's not just the water they drink, but also the water it takes to grow all of the food they will eat over their lifetime. (A kilogram is roughly equal to two pounds; a liter is about a quart.)