Population increased and land became scarce. In the mid 1980's, the earth's population is expected to reach the five billion level rising to six billion well before the year 2000. The rate of population growth indicates that the world's food requirement will present a shortage problem. Food production is lagging behind population growth. Problems of feeding the rapidly increasing world population includes requirements for irrigation and fertilizer products which in turn require large amounts of energy input. The interrelationship of energy and human members can be better appreciated when it is recognized that energy use has been increasing faster than the world population. The world doubled its energy consumption within the past decade while the world population doubled its numbers in about the past 30 years. Petroleum energy has been demonstrated to be an important input to increase food production. When the energy becomes a shortage man has to develop technology for new energy sources and more effective population controls, but these are future aims. In the meantime, we must find ways to increase food production on the world's limit of land resources through the effective use of fossil energy. It may be possible for the world population to be fed if energy, land, and water resources are used effectively.