It has been said that arguing vegetarianism on moral grounds is a no-win situation. Looking at the issue from a strictly energy angle reveals a new perspective on the debate of the merits of vegetarianism that can be empirically argued. According to the 2nd Law of Thermodynamics, in every transformation of energy (i.e. sun’s energy to plants via photosynthesis and from plants to animals) there is a roughly 90% decrease in available energy. In other words, only 10% of a plant’s energy is transferred to the consumer. Taking this a step further, vegans embrace a diet free of animal products entirely, thereby eating lower on the food chain.
According to a study from two researchers at the University of Chicago, “a person consuming a mixed diet with the mean American caloric content and composition causes the emissions of 1,485 kg CO2 -equivalent above the emissions associated with consuming the same number of calories, but from plant sources. Far from trivial, nationally this difference amounts to over 6% of the total U.S. greenhouse gas emissions.” In other words, someone who eats an average American diet is responsible for the additional emissions of one and a half tons of carbon dioxide. According to a Slate.com article, the difference “mostly come[s] about because of the disparity between the fossil fuel required to produce a calorie’s worth of grain vs. that needed to make a calorie’s worth of beef; grain is nearly a dozen times more efficient in this regard. Cattle are also a huge source of methane, a particularly noxious greenhouse gas; it’s estimated that bovines are responsible for roughly triple the methane emissions of the American coal industry.”
On the other hand, Cornell researchers suggest “a limited amount of meat may actually increase [the] efficiency” of one’s diet. Christian Peters, lead author of the study, found that “‘A person following a low-fat vegetarian diet . . will need less than half (0.44) an acre per person per year to produce their food.’” He goes on to state that “‘A high-fat diet with a lot of meat, on the other hand, needs 2.11 acres.’” Mr. Peter’s findings indicate that a “‘vegetarian diet is vegetarian diet is not necessarily the most efficient in terms of land use.’” These findings stem from the fact that “vegetables and grains must be grown on high-quality cropland. . . . Meat and dairy products from ruminant animals are supported by lower quality, but more widely available, land that can support pasture and hay.”
The website Vegan Outreach highlights four areas (Climate Change, Water, Land Degradation and Biodiversity detailed below) in their argument for consuming vegan diet.
Climate change: Climate change is the most serious challenge facing the human race. The livestock sector is a major player, responsible for 18 percent of greenhouse gas emissions measured in CO2 equivalent. This is a higher share than transport….Livestock are also responsible for almost two-thirds (64 percent) of anthropogenic ammonia emissions, which contribute significantly to acid rain and acidification of ecosystems.
Water: The livestock sector is a key player in increasing water use, accounting for over 8 percent of global human water use, mostly for the irrigation of feedcrops. It is probably the largest sectoral source of water pollution, contributing to eutrophication, “dead” zones in coastal areas, degradation of coral reefs, human health problems, emergence of antibiotic resistance and many others. The major sources of pollution are from animal wastes, antibiotics and hormones, chemicals from tanneries, fertilizers and pesticides used for feedcrops, and sediments from eroded pastures.
Land degradation: Expansion of livestock production is a key factor in deforestation, especially in Latin America where the greatest amount of deforestation is occurring – 70 percent of previous forested land in the Amazon is occupied by pastures, and feedcrops cover a large part of the remainder.
Biodiversity: The livestock sector may well be the leading player in the reduction of biodiversity, since it is the major driver of deforestation, as well as one of the leading drivers of land degradation, pollution, climate change, overfishing, sedimentation of coastal areas and facilitation of invasions by alien species.
Not only does vegetarianism consume less energy, but the health benefits are also persuasive. Author Michael Pollan’s tag line for his 2008 book In Defense of Food: An Eater’s Manifesto is “Eat Food. Not too Much. Mostly Plants.” Mr. Pollan’s previous book, The Omnivore’s Dilemma: A Natural History of Four Meals delves into the unfortunate state of food with his statement that the foods we consume are “no longer the products of nature but of food science. Many of them come packaged with health claims that should be our first clue they are anything but healthy.”
Whether one decides to eat a largely vegetarian diet for the potential health benefits or the decreased energy and greenhouse gas emissions depends on their personal beliefs. However, cutting back on the consumption of animal products has been touted as a viable step to reduce one’s footprint, not to mention a lower risk of certain diseases associated with eating read meat.
- Eric Wilson
[image source: AskJacksonFirst.com]