In a newly released report, the U.N. Population Fund has determined that in mid-October the world population will reach 6 billion. This century alone has seen a 400% increase in the number of people inhabiting the planet Earth, from 1.5 billion to 6 billion. The U.N. study projects that by the year 2050, 8.9 billion people will populate Earth.

Population growth is not evenly distributed: growth has slowed in the industrialized areas of Europe, North America, and Japan. It continues to soar in sub-Saharan Africa, and South and West Asia. While China remains the world's most populous nation with 1.5 billion people, according to the U.N. report India is projected to surpass China in less than 50 years.

Experts debate whether Earth's natural resources can continue to support the booming population. Other factors, such as longer life expectancy and declining fertility, may also affect future growth rates.

You can access a press summary, the full report, and other news features based on the report at the United Nations Population Fund site: The State of World Population 1999.

Learn about the Problem

There are many factors that affect a population's growth. You can learn about some of them in the activity Biology Gateways: Factors Affecting Population Growth.

A common concern about the exponential growth of the human population is that the Earth's natural resources will be strained beyond an ability to support the population. Learn about carrying capacity and limiting factors in the activity Biology Gateways: Carrying Capacity.

Think about the Problem

The activities in the Learn about the Problem section deal with plant and animal species, but the concepts are valid for the human population as well.

• The world's human population started growing exponentially only about 500 years ago. What factors do you think enabled this rapid growth? What factors will possibly limit rapid growth in the future?
  
  
• Human beings are the only species that can consciously alter some of the factors affecting population growth. How does this fact affect demographic trends in the human population? (Demographics are the study of the dynamic balance of a population, especially with reference to size and density, growth, distribution, migration, and vital statistics, all affecting social and economic conditions.)

For the Teacher: Extending the Problem

• The U.N. Population Fund site offers this motto: "Population is about people, not about numbers." The site provides a newsline about issues affecting the world population and the quality of life in different regions, a discussion of the issues and factors of the "6-billion milestone," details about Fund programs, and more.
  
  
• The Population Reference Bureau provides objective information on international population trends and their implications. Students can find information about topics such as hunger, migration, aging, demographics, and much more.
  
  
• The Washington, D.C.-based Population Institute is the world's largest independent, non-profit, educational organization dedicated exclusively to achieving a more equitable balance between the world's population, environment, and resources. The Institute sponsors World Population Awareness Week, to be observed this year from October 10-16. Have your students prepare posters for display during WPAW. Remind students that the population issue is much more complex than birth rate, so they shouldn't get sidetracked by a pro-con discussion of birth control issues.