http://www.populationconnection.org/article/population-meat-consumption/

Although rates of consumption vary greatly from country to country, global meat consumption is on the rise. As their middle classes expand, populous countries like China and India have seen an increased demand for meat products. And although growing concerns about the undeniable health and environmental impacts of meat-heavy diets have led to the meatless Monday trend in the U.S., Americans still eat more meat than almost anyone else in the world—an average of 270.7 pounds per person every year.

Factory farming and the use of pesticides and fertilizers have allowed us to mass-produce more food, including meat, than previously possible. However, this increased productivity comes at a cost. Meat production is incredibly resource intensive and environmentally damaging. And if, as projected, global population reaches 9.6 billion people in 2050, the costs will only grow.

Meat and Resource Consumption

Producing meat is a very inefficient process. Livestock production requires significant inputs of food, water, land, and energy in order to raise, transport, and process the animals. We produce more meat today than ever before—about 300 million tons each year. This increased productivity has been made possible due to factory farming methods and increased feedstock production, which has been enhanced with fertilizers and technological and genetic advances. According to the Worldwatch Institute, global meat production has tripled since the 1970s and has risen by 20 percent just between 2000 and 2010.

Such a high rate of meat production takes a heavy toll on natural resources. Growing sufficient crops to feed livestock requires a tremendous amount of land—land which could be more efficiently used for crops. Taking into account the amount of cropland devoted to feedstock, an estimated 75 percent of the world’s agricultural land goes into meat production. Meat production is also extremely water-intensive; producing one pound of meat requires between 5,000 and 20,000 liters of water, while producing one pound of wheat requires much less—between 500 and 4,000 liters.

And the resource costs of meat production don’t end with food and water; fossil fuels are also an essential part of the equation. In terms of the fossil fuel energy required to produce animal protein, broilers—that is, chickens raised for consumption—are the most efficient with an energy input to kcal ratio of 4:1. Pork is much less efficient at a ratio of 14:1, and beef is even less efficient; the ratio for energy input to protein is 40:1. For all animal protein production, the average ratio of energy input to protein is 25:1, over 10 times greater than the energy needed to produce one kcal of plant protein. The inefficiencies of meat production are also apparent in the feedstock inputs. For each kilogram of broiler meat produced, 2.3 kilograms of grain is required. One kilogram of beef requires a total of 43 kilograms of grain and forage input.

“There will not be enough water available on current croplands to produce food for the expected population of 9 billion in 2050 if we follow current trends and changes towards diets common in western nations.”

—Malin Falkenmark, Senior Scientific Advisor, Stockholm International Water Institute (SIWI)

Meat and Pollution

Meat production is not only resource intensive. It is also a source of significant air and water pollution. In order to feed the growing livestock population, the agricultural process has continued to intensify, relying heavily on the application of chemical fertilizers and pesticides. Aside from the depletion of resources necessary to produce these fertilizers, runoff from their use causes extensive environmental damage. This is compounded by the effect of manure runoff from the livestock production system. In China, agriculture is the leading driver of water pollution due to manure and fertilizer runoff, both associated with the industrialized livestock production system. Phosphorus, nitrogen, and other nutrients from this runoff flow into waterways and cause toxic algal blooms. These blooms then deprive areas of oxygen, hurting fish populations and affecting those who rely on fishing for income or for sustenance.

Global meat production is also responsible for a significant fraction of all greenhouse gas emissions—between 7 and 18 percent, according to the Food and Agriculture Organization of the United Nations. Methane, carbon dioxide, and nitrous oxide are the primary greenhouse gasses associated with livestock production. This includes direct emissions from enteric fermentation (a digestion process for ruminants such as cattle and sheep) and indirect emissions from the conversion of forests and other vegetated lands into arable land for feed production. Additional greenhouse gas emissions linked to the production process come from the application of chemical fertilizers on crops that feed the livestock, manure management, and international transport. According to the U.S. Environmental Protection Agency, ruminant livestock produce 80 million metric tons of methane each year, making up 28 percent of all methane gas emissions worldwide.

Toward a Sustainable Future

Meeting global animal protein demands places a heavy burden on our natural resources, thus threatening our ability to feed our rapidly growing global population. As demand for meat increases, so too will associated greenhouse gas emissions. Soil will erode as land is continually used for crop production—most of which is converted into livestock feed—water resources will be strained, and forests will be degraded as agricultural land expands to meet animal protein demands.

According to Vaclav Smil, professor of environment and geography at the University of Manitoba, if everyone in the world ate as much meat as the average person in the Western world, we would need two-thirds more land than we are currently using. As global population grows and demand for animal proteins increases, this shortfall will only grow. Reducing meat consumption and choosing sustainably produced meats could help lighten the burden meat production currently places on our resources. However, in order to feed the more than 9 billion people projected to live on our planet by 2050, we will need to make dramatic changes to our meat production systems, as current practices are simply unsustainable. Stabilizing our population will be vital as we strive to meet global nutritional needs.