U.S. meat consumption by U.S. adults exceeds the government’s Recommended Daily Allowance (RDA) of protein. According to one study, American men consume almost twice the recommended amount of protein. Scientific evidence (See Meat and your Health) is increasingly clear that eating large quantities of beef and processed meats increases our exposure to toxins and is linked to serious health problems such as heart disease, cancer and obesity.

Lamb, beef, pork and cheese generate the most greenhouse gases, primarily methane and nitrous oxide. That’s because producing them requires the most resources – mainly animal feed, fuel, water, fertilizer and pesticides. Pound for pound, these four foods result in more manure than other proteins, which in turn generates more methane and nitrous oxide, two potent greenhouse gases. Red meat (lamb, beef and pork) account for 54 percent of the meat Americans eat.

High-protein foods with the least emissions include lentils, tofu, beans and peanut butter. If everyone in the U.S. skipped meat and cheese just one day a week and replaced them with a vegetable-based protein, it would be like not driving 91 billion miles, or taking 7.6 million cars off the road.

Producing 70 billion pounds of meat for domestic consumption takes large amounts of environmentally destructive and energy-intensive pesticides, fertilizer, fuel and water. It also generates large amounts of toxic manure and wastewater that pollute groundwater, rivers, streams and, ultimately, the ocean (as in the Gulf of Mexico’s “dead zone”).

U.S. meat consumption has been holding steady, but global meat production tripled from around 200 billion pounds in 1971 to around 600 billion pounds in 2010, while world population grew by just 81 percent. At this rate, production will double by 2050 to approximately 1.2 trillion pounds of meat per year, requiring more water, land, fuel, pesticides and fertilizer and causing significant damage to the planet and global health.