Eat none and cut greenhouse gas emissions by 18%

Grain fed to U.S. livestock could feed 840 million people on plant-based diet

BY THOMAS GOUNLEY FOR GREENING OF OIL

Originally, this column was going to be about the environmental benefits of vegetarianism. Then I realized that was missing the point. Not everyone is going to become a vegetarian, but cutting back on meat consumption is a very realistic goal. And it can have definite environmental benefits. The call to eat less meat for environmental reasons has come from some pretty high places.

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In September 2008, Dr. Rajendra Pachauri, chair of the United Nations Intergovernmental Panel on Climate Change, said people should start with one meat-free day a week, and increase from there.

In February 2009, the president of Germany’s environmental agency, the UBA, recommended that German citizens lower their meat consumption in an effort to decrease their carbon footprint and stop global warming. This is Germany, where 39 percent of the average citizen’s total caloric intake comes from meat and meat products.

And it’s not just world environmental leaders doing this. In November 2009, Rabbi Eric Yoffie, the head of the Reform Judaism movement, suggested that Reform Jews eat less red meat, citing environmental as well as ethical and health reasons.

Meat yields 18% GHG, world’s planes, cars, trains, boats 13%

In 2006, the United Nation’s Food and Agriculture Organization estimated that meat production accounts for 18 percent of greenhouse gas emissions. In comparison, it estimated that the world’s planes, cars, trains, and boats accounted for 13 percent of emissions.

To get into the nitty-gritty science behind this, we need to talk about trophic levels. Trophic levels refer to the levels in an ecosystem’s food chain. Think of the food chain as a pyramid.

At the bottom, you have primary producers—organisms that convert energy obtained from a source (generally sunlight) into biomass. For our purposes, this level includes plants, although other organisms such as phytoplankton are on this level too.

On the next level up you have the primary consumers, those organisms that consume the primary producers. These are generally herbivores consuming the plants.

On the next level up you have the secondary consumers, those organisms consuming the primary consumers, essentially carnivores. Beyond those you have the tertiary consumers and so on, generally up to a maximum of five levels of consumption.

First law: energy cannot be created or destroyed

There are two laws relating to energy flow through ecosystems.

The first law of thermodynamics states that energy cannot be created or destroyed—it can only change form.

The second law of thermodynamics states that whenever energy is transformed, there is a loss of energy through the form of heat. This second law is key. Only 10 percent of energy transfers when you move between levels. So only about 10 percent of energy in the primary producers is passed on to primary consumers, and only 10 percent of the energy in the primary consumers (or 1 percent of the energy from the primary producers) is passed on to the secondary consumers.

This energy loss is due to a variety of factors, such as respiration, energy expended by activity and incomplete digestion. This is why the food chain is like a pyramid, with each trophic level smaller than the one below it.

Going vegan for one year saves 1.5 tons of emissions

Thus, it requires less energy to support a vegetarian diet than a meat-based one. It takes 16 pounds of grain and soybeans to produce a pound of beef raised in a traditional feedlot. According to a 2003 Cornell University study, the amount of grains fed to livestock in the United States could feed about 840 million people who follow a plant-based diet.

This is why any ecosystem is going to have fewer large carnivores than herbivores. Put another way, a 10-acre farm could support 60 people growing soybeans, 24 people growing wheat, 10 people growing corn and only two producing cattle.

Three times as much fossil fuel needed to produce a meat diet

So how does this relate back to fossil fuels?

Three times as much fossil fuel is needed to produce a meat-centered diet as opposed to a vegetarian diet.

A 2008 University of Chicago study concluded that going vegan for one year saves 1.5 tons of emissions relative to the standard American diet (in addition to meat, vegans do not consume other animal products such as dairy and eggs).

This energy savings is 50 percent greater than the savings that would come from switching from an SUV to a Toyota Prius for the same time period.

And then there is water and land use

Another problem associated with conventional meat production is the use of land and water resources.

In terms of land usage, the problem isn’t necessarily land used for grazing, but rather to produce the crops needed to feed the animals. Eighty percent of the corn and 95 percent of the grain raised in the United States goes to meat production.

As meat consumption and production increases, the need for more agricultural land leads to deforestation and a decrease in the ability to convert carbon dioxide.

In terms of freshwater resources, producing 1 kilogram of animal protein requires 100 times more water than 1 kilogram of grain protein.

In addition, 40 kilograms of excrement is produced for every kilogram of beef produced, more than can naturally be used for fertilizer, so there is a large amount of waste to deal with as well. In fact, the Environmental Protection Agency estimates that animals in the United States produce three times as much raw waste as humans.

When you do, grass-fed beef better

One’s personal diet is something that most people have a significant amount of control over, so it can be fairly easy to make positive changes environmentally.

Getting back to the idea we started with, there is no clear line defining that being vegetarian is environmentally friendly, whereas eating any amount of meat is not.

Cutting back on meat consumption—even a small amount—results in environmental benefits. It can mean meat-free meals or cutting back on portion sizes when you do eat meat.

When you do eat meat, go for quality over quantity, and look into grass-fed beef, which alleviates some of the negatives explained above.

About Thomas Gounley

Thomas Gounley is an undergraduate student at the University of New Hampshire, where he’s double-majoring in Environmental Conservation Studies and English-Journalism, with the eventual goal of getting into science or environmental journalism. He’s a staff writer for UNH’s twice-weekly newspaper The New Hampshire, where he covers issues related to science and sustainability.

When not writing or in lab, he enjoys running, cycling, hiking and any other excuse to get outside. He’s a leader in UNH’s Outing Club, and is looking forward to finishing his quest to summit all 48 peaks in New Hampshire above 4000 feet. Originally from Virginia, he also enjoys traveling and photography.

Contact Thomas Gounley at: tai36@unh.edu

Visit his blog: http://va2nh.wordpress

Follow him on Twitter: www.twitter.com/tgounley