Contrasting views on human population growth
One wisdom justifies complacency: the other demands action now
World population reached 6 billion on 12 October, according to the best guess of demographers. It has tripled in a single lifetime, is projected to increase by half as much again next century, and, if current declines in fertility falter, could yet double. We have heard such statistics before, to the point of population crisis fatigue. Yet we are living through a spectacular phenomenon in demographic history. Three quarters of the 1000-fold increase in human numbers since agriculture emerged 10,000 years ago has occurred during this past century - 75% of the absolute increase in 1% of the time.
The size of the human population is an important determinant of its condition. It is increasingly the combination of human numbers with levels of consumption and types of technology that determines the impact on the environment - and whether that impact exceeds the local or global carrying capacity. Humanity's response to