1. Population Geography Population Growth
Over 7 billion people live on Earth, and most of them live on about 30 percent of the planet's land area.
The population of countries or regions changes over time depending on the area's birthrate, death rate, and the migration of people to or from the area.
Rapid population growth presents many challenges, including producing enough food and shortages of resources such as water and housing. Other concerns include adequate health care, access to medicine, and technology, and loss of cultural traditions.

2. Population Geography Population Distribution
Most of Earth's population lives on land with fertile soil, available water, and a mild climate; human settlements generally avoid mountains, deserts, and tundra areas that make life difficult.
To determine population density in a country, geographers divide the total population of the country by its total land area.
In a pattern called urbanization, trends indicate that many people are moving from rural villages to cities in order to find a better life and jobs in more prosperous urban areas.