THE EXPANDING HUMAN POPULATION

Overpopulation is the root cause of human-induced global warming and depletion of resources for future generations. From the beginning of humankind to just over 100 years ago, the world's human population was less than one billion. Our planet now holds between 5 and 6 billion persons with a growth rate that will take us over 10 billion by the middle of the next century (figure 23.1). The present net increase in population amounts to about 90 million people a year. Growing population is a twoedged sword. Increasing numbers of people, supported in adequate living standards by advancing technology, represent an expanding reservoir of personalities, innovative ideas, and the creative seedcorn for future developments in both technological and humanistic spheres of existence. On the other hand, unbridled population growth that outpaces technological developments designed to stem its negative impacts could push humanity into a downward spiral of resource depletion, decreased overall living standards, and ever more profound alteration of natural systems by human activities.

Approximately 30 countries – most of Europe along with Japan – have achieved a roughly zero population growth rate (actually, an annual growth rate of less than 0.3%, as defined by the Washington, DC-based Worldwatch Institute).