About half the earth’s biological production capacity has already been diverted to human use. Life-supporting ecosystems are affected everywhere by the planet’s 6.7 billion people, which is projected to reach at least 9.2 billion by 2050. This document, by the UNFPA, explores the links between population and environmental quality. It recognizes how complex and varied the links may be, and that slowing the rate of population growth may give countries time to take measures to meet people’s needs, while protecting the environment through various means. The UNFPA also gives suggestions on what can be done, and explains what it is doing currently.