The Worldwatch Institute estimates that raising domesticated animals for food accounts for 51 percent of all human-caused greenhouse gas emissions. ©Candice Gaukel Andrews

One of my favorite things about writing a regular eco-travel and environmental column is getting to read the comments that come in. Sometimes readers are complimentary, sometimes they are critical and sometimes they challenge me.

Such is the case with an article I recently wrote on soil and climate change. On one forum, a reader commented, “If you think climate change is a problem but are not vegan, you are seriously confused.

He may be right. In 2009, the Worldwatch Institute estimated that livestock contributed more than half of the world’s greenhouse gases to the atmosphere.

Beef production alone uses about three-fifths of the world’s farmland. ©Candice Gaukel Andrews

But is getting most of the planet’s people to eliminate animal products from their diets in order to curb rapid climate change realistic—or best for human health?

The greenhouse gas and meat connection

Fossil fuel use—especially of coal, natural gas and oil—is certainly a major source of human-caused emissions of carbon dioxide and other greenhouse gases (GHGs). But according to a 2009 Worldwatch study, the life cycle and supply chain of domesticated animals raised for food (buffalo, camels, cattle, goats, horses, pigs, poultry and sheep) has been vastly underestimated as a source of GHGs: in fact, it accounts for a shocking 51 percent.

The authors of the Worldwatch report state that besides the methane and nitrous oxide released during livestock production, the industrialized livestock industry is also accountable for approximately 75 percent of global deforestation, since forests are cut down to give the animals grazing grounds and to grow soybeans used in feedstock. And beef production alone uses about three-fifths of global farmland, even though it yields less than 5 percent of the world’s protein.


Eating a plant-based diet might prevent you from absorbing the nutrients you need, so you may have to eat more plant protein to make up for this lower absorption.

However, it should be pointed out that not all studies have shown the same results as Worldwatch’s. In 2004, the United States Environmental Protection Agency found that agriculture contributed only 14 percent of worldwide GHG emissions. A later, 2006 United Nations Food and Agriculture Organization food report pegged that contribution at 18 percent. More recently, in December 2014, Chatham House, an international think tank based in the United Kingdom, published a study that found that greenhouse gas emissions from the livestock sector account for 14.5 percent of the global total.

But plants are not perfect

Switching to a vegan diet, though, does have its drawbacks. According to Dr. Nancy Rodriguez, a professor of nutritional sciences at the University of Connecticut, Storrs, individuals who stop eating meat and dairy products are at risk of not getting enough calcium, iron, vitamin B12 and vitamin D, and zinc in their diets—all nutrients that come mostly from food products derived from animals.

Insufficient calcium and vitamin D compromise bone structure, and a lack of zinc can hinder growth in children. Iron and vitamin B12 assist in the production of red blood cells, which deliver oxygen throughout the body. A vitamin B12 deficiency can lead to severe anemia, neurological problems, and even paralysis and death.

Solely eating a plant-based diet can also be problematic if you have a gluten intolerance or celiac disease. ©Candice Gaukel Andrews

Plant-based foods, unable to run away from predators, defend themselves by producing chemicals. Many of these compounds, such as lectins and phytic acid, interfere with the digestion of protein and the absorption of minerals, especially calcium, iron, magnesium and zinc. Eating a plant-based diet, then, can prevent you from properly absorbing the nutrients your body needs, so you may have to eat more plant protein to make up for the lower absorption.

Following a plant-based diet—especially one that includes grains such as barley, oats, rye and wheat—can lead to a higher consumption of gluten, which can be problematic for people with gluten intolerance or celiac disease.

Is a plant-eating world even possible?

Even if it’s desirable and necessary for the environment, getting the world to switch to a vegan diet may be a Sisyphean task. While meat consumption in the United States has fallen, it’s a small decrease compared with a rising demand in China. World meat production is projected to double by 2050.

Albert Einstein believed in the benefits of a vegetarian diet. ©Holly Glessner

It’s interesting to note that on August 3, 1953, Albert Einstein wrote in a letter to Max Kariel, “I have always eaten animal flesh with a somewhat guilty conscience.” After he became a vegetarian, he penned on March 30, 1954, “So I am living without fats, without meat, without fish, but am feeling quite well this way. It always seems to me that man was not born to be a carnivore.”

When it comes to a world in the throes of rapid climate change, he—and my reader—may be right.

If governments worldwide started encouraging vegetarianism in their dietary guidelines, do you think could we make a real difference in slowing climate change?

Here’s to finding your true places and natural habitats,