Human Population Growth

Free Response

Describe the age structures in rapidly growing countries, slowly growing countries, and countries with zero population growth.


Rapidly growing countries have a large segment of the population at a reproductive age or younger. Slower growing populations have a lower percentage of these individuals, and countries with zero population growth have an even lower percentage. On the other hand, a high proportion of older individuals is seen mostly in countries with zero growth, and a low proportion is most common in rapidly growing countries.

Since the introduction of the Endangered Species Act the number of species on the protected list has more than doubled. Describe how the human population’s growth pattern contributes to the rise in endangered species.


Continued exponential human population growth results in the human population requiring more resources to sustain itself. These resources are usually taken at the expense of the environment and the organisms that rely on the resources in that environment (e.g., habitat destruction for human development, water rerouting for irrigation, etc.). The continued use of fossil fuels to generate power for human activities also contributes to climate change, changing climates in some areas so that certain species can no longer survive there.