Worldwide, 2 billion people live primarily on an animal-based diet, while double that amount, or 4 billion people, live primarily on a plant-based diet. In fact, the United Nations Environment Program (UNEP) estimated that calories lost from feeding cereals to animals could feed an extra 3.5 billion people.
Another analysis showed that 4 billion people could be fed with the crops devoted to livestock. Researchers found that the single biggest intervention to free up calories would be to stop using grains for cow carcass production in the US. The US, China and Western Europe account for the bulk of the 'diet gap,' and corn is the main crop being diverted to animal feed.
The UN World Health Organization (WHO) estimated that the number of people fed in a year per hectare ranged from 22 individuals for potatoes and 19 for rice, to one and two persons, respectively for cow and sheep carcass. It added that the low energy conversion ratio from feed to carcass is a concern, since much of the cereal grain food produced is diverted to livestock production.
A Bangladeshi family living off rice, beans, vegetables and fruit may live on an acre of land or less. However, the average American, who consumes around 270 pounds of animal carcass a year, needs 20 times that. The current global average animal consumption is 100g (3.5 ounces) per person per day, with about a ten-fold variation between high-consuming and low-consuming populations.
For most people in developing countries who obtain their protein from plants, eating animal flesh is a luxury. A kilogram (2.2 pounds) of animal carcass can cost from $2 to $5 in the local markets, which is several days' wages. A typical African eats only 20 kg (44 pounds) of animal flesh a year, well below the world average.
These findings suggests that over-consumption and the type of diet being used are of the essence for understanding resource use and greenhouse gas emissions, as opposed to increasing population by itself being the primary driver, as others argue. That is, population's importance is related to over-consumption, and more specifically to the over-consumption class. The beefed-up diets of the expanding global middle-class could lead to chronic food shortages and water-scarcity.
Government policies and trade agreements are driving demand for animal products by encouraging the globalization of Western diets and consumption patterns, and by facilitating animal products at artificially low prices via subsidies on livestock feed. The US alone spends $38 billion each year to subsidize meat and dairy, while greenhouse gas (GHG) have risen 61% from 1990 to 2013. Demand for animal products is projected to increase by 50 percent from 2013 to 2025, much faster than human population. Due to the vast amounts of land required for both intensive and free-range farming of animals, livestock will continue to cause rapid global warming.
Just like we can and must use renewable energy and practice energy conservation, we can and must change government policy and our diet. Lowering subsidies for livestock feed, and lowering meat and dairy consumption, are essential to lowering greenhouse gases.
Excerpt from the book, "Meat Climate Change," see http://meatclimatechange.org/