About forty years ago, the world population was only 3.5 billion, or about half of the present population of 6.7 billion people. Most of us seem to ignore or be unaware of the magnitude of this rapid expansion and the vast changes that it is causing throughout the world. Indeed, the daily and even the annual impacts of this growth go unnoticed. Yet the impacts of the growing world population on land, water, energy, and biota resources are real and indeed overwhelming.
What resources are required to secure a quality life for future generations worldwide? Will there be sufficient cropland, water, energy, and biological resources to provide adequate food and other essential human needs? Balanced against the future availability of these basic resources are the escalating needs of an ever-growing population.
Clear scientific evidence suggests worldwide problems of food availability already have emerged. According to the World Health Organization, nearly 60 percent of the world population now is malnourished—the largest number and proportion of malnourished people ever reported in history. Further, many serious diseases, like malaria, HIV/AIDS, and tuberculosis are increasing, not only because of worldwide malnutrition but also because the increasing density and movement of human populations facilitate the spread of diseases.