1. Human Population Growth
Chapter 5.3
Human Population Growth

2. The size of the human population increases with time.
Developed countries have a low growth rate, which developing countries have a high growth rate.
Most of human existence the growth rate has been low because of limiting factors and the harshness of life.
Agriculture and industry have made life easier and safer, the food supply more reliable, and there is shipping around the world. This increased the growth rate.
Historical Overview

3. Patterns of Population Growth
The human population cannot keep up it’s current rate of growth because the Earth’s resources are limited.
Thomas Malthus observed human population and came up with the idea that war, famine, disease would limit population growth.
Today the study of human populations is called demography.
Birthrates, death rates, and age structure of a population predict why certain countries have high growth rates while other don’t.
Patterns of Population Growth

4. The Demographic Transition
Demographic transition – a dramatic change in birth and death rates.
Usually humans have had high birth and death rates. With current advances children survive to adulthood more and adults live to old age. These change lowered the death rate. During this time birthrate stays the same so population growth is drastic. As societies modernize families tend to have fewer children so population growth slows.
Most countries have not completed the demographic transition.
The Demographic Transition

5. Age-structure diagrams – population profiles, show the country broken down by gender and age group.
This can help predict if there is going to be population growth.
Age Structure

6. Future Population Growth
Demographers have to look at age structure, diseases, and other factors to predict the growth rate.
There is a great debate on what will happen if the growth rate doesn’t slow down or stop.
Future Population Growth