ABSTRACT
How long can we go on eating oil? Before we try to answer this question, it is desirable to understand how and why we do eat it. If you live in a developed country like the United States or the United Kingdom, every mouthful of food you eat—unless you gather wild berries by the roadside—irrevocably consumes a finite amount of irreplaceable fossil fuel energy. This is because direct energy in the form of tractor fuel and indirect energy in the form of fertilizers are put into the operations of growing plant food and rearing animal food, and because energy is used in processing, distributing, and preparing food. Each of these stages uses some fossil fuel energy, so by the time the food reaches your table it has accumulated a fossil fuel energy “input.” (This is different from the energy that your body can get from food by eating it, which is commonly measured by the “calorie content” and which is the energy “output.”) We eat oil, therefore, by putting fossil fuel energy into the processes of food production, into the nation’s “food system.”
