The chair of the UN’s Intergovernmental Panel on Climate Change, the winner of the 2007 Nobel Peace Prize (along with former Vice President Al Gore), has made a surprising recommendation for the most immediate impact a person can have toward reducing greenhouse gas emissions: change what you eat. Emissions from automotive vehicles are one leading cause of global warming. But about a fifth of greenhouse gasses are attributable to animal agriculture involved in meat production, according to the UN’s Food and Agriculture Organization. Cultivating the crops for animal feed involves tremendous energy use, from pumping water to producing fertilizer. Thus, becoming a vegetarian can significantly reduce a person’s “carbon footprint”—the amount of greenhouse gasses their lifestyle is responsible for. We examine this fascinating idea as well as benefits of a plant-based diet to other aspects of human health. Hear voices of many people who’ve made the switch to a plant-based diet, a distinguished nutritionist, and others.

We found that the amount of meat in the diet can easily be equated [in global warming impact] to the type of car one drives, or how many miles one drives. Eliminating meat from the diet is the difference between driving a Prius, or driving the standard American Camry, for example. So, you know, you can buy a Prius and have the same savings you would have if you would just eliminate meat from your diet.”

—Pamela Martin, climate scientist at the University of Chicago