Cherish the Earth
In the course of the present century, the world population has increased from less than two thousand million to over five and a half thousand million. Until one hundred years ago, the expanding population's increasing needs for food, fuel, fibre and construction materials were met from the land by cultivating progressively larger areas. In the course of the next twenty-five years a further two thousand million people will be added to the global population. Most of these people will live in the tropics.