From farm to plate, the modern food system relies heavily on cheap oil. Threats to our oil supply are also threats to our food supply. As food undergoes more processing and travels farther, the food system consumes ever more energy each year. The U.S. food system uses over 10 quadrillion Btu (10,551 quadrillion Joules) of energy each year, as much as France's total annual energy consumption. Growing food accounts for only one fifth of this. The other four fifths is used to move, process, package, sell, and store food after it leaves the farm. Some 28 percent of energy used in agriculture goes to fertilizer manufacturing, 7 percent goes to irrigation, and 34 percent is consumed as diesel and gasoline by farm vehicles used to plant, till, and harvest crops.