Making the link: population, health, environment.
The number of people on Earth, where they live, and how they live all affect the condition of the environment. People can alter the environment through their use of natural resources and the production of wastes. Changes in environmental conditions, in turn, can affect human health and well-being. Human demographic dynamics, such as the size, growth, distribution, age composition, and migration of populations, are among the many factors that can lead to environmental change. Consumption patterns, development choices, wealth and land distribution, government policies, and technology can mediate or exacerbate the effects of demographics on the environment. The precise impact of a given change depends on the interplay among all these factors, but it is clear that demographic change can affect the environment. (excerpt)