If you thought the food chain's biggest contribution to climate change was the methane emitted from animals, guess again. It turns out that approximately 20% our fossil fuel consumption goes toward feeding ourselves. According to Michael Pollan, author of the excellent new book, "The Omnivore's Dilemma," the most worrisome aspect of the current U.S. food system is its reliance on fossil fuels.
Pollan says that this happens in three places. First, farms use enormous quantities of synthetic nitrogen fertilizer, which is made from natural gas and a great deal of electricity.
Second, commodity crops (such as corn, soybeans and wheat) are processed so intensely that we add seven calories of fossil-fuel energy for every one calorie of food produced. According to Pollan, "It's a very intensive process to take the corn and turn it into the high-fructose corn syrup, or take the corn and turn it into the chicken, and the chicken into the Chicken McNugget. As we move further away from eating food to eating highly processed, complicated food products -- as we move from yogurt to Go-GURT -- it takes more energy, and more energy in the packaging."
Third, our food arrives from all around the world and in the United States travels an average of 1,500 miles before it arrives at our plate.