1. Chapter Nine: The Human Population

2. Section One: Studying Human Populations
Demography: the study of populations
The Human Population Over Time
Underwent exponential growth in the 1800’s
Unlikely the world can sustain this growth in the future

3. Section One: Studying Human Populations
Forecasting Population Size
Age structure: the distribution of ages in a specific population at a certain time
Graphed in population pyramid
More young people= more population growth
Survivorship: the percentage of members of a group that are likely to survive to any given age
Graphed in a survivorship curve
Type of curve based on whether the country is developed

4. Section One: Studying Human Populations

5. Section One: Studying Human Populations

6. Section One: Studying Human Populations
Forecasting Population Size
Fertility Rates: the number of babies born each year per 1000 women in a population
Total fertility rate: the average number of children a woman gives birth to in her lifetime
Replacement level: the average number of children each parent must have to “replace” themselves in the population
Migration: the movement of individuals between areas
Immigration: movement into an area
Emigration: movement out of an area

7. Section One: Studying Human Populations

8. Section One: Studying Human Populations
Declining Death Rates
More people have access to food, clean water, and safe sewage disposal
Life expectancy: the average number of years the members of a population are likely to live
Affected by infant mortality rate
Infant mortality rate: the death rate of infants less than one year old

9. Section One: Studying Human Populations

10. Section One: Studying Human Populations
The Demographic Transition
The model that describes how economic and social changes affect population growth rates
4 stages of transition

11. Section One: Studying Human Populations

12. Section One: Studying Human Populations
Women and Fertility
Increasing education and economic independence has led to a decline in birth rate
Total fertility rate in developing countries= 3.1 children
Total fertility rate in developed countries= 1.6 children

13. Section Two: Changing Population Trends
Problems of Rapid Growth
Infrastructure: the basic facilities and services that support a community
Ex: water supplies, sewer lines, roads, schools, hospitals
Rapidly growing populations use resources faster

14. Section Two: Changing Population Trends
Problems of Rapid Growth
Shortage of Fuelwood
Rapid growth lead to more wood being used and trees being cut down
Wood is a main source of fuel in many countries
Used for cooking food, boiling water, and keeping warm
Unsafe Water
Water may be used for drinking and sewage disposal
Unclean water serves as a breeding ground for diseases
Ex: typhoid, cholera, dysentery

15. Section Two: Changing Population Trends
Problems of Rapid Growth
Impacts on Land
Arable land: land that can be used to grow crops
Growing populations make trade-offs between competing uses for land such as agriculture and housing
Urbanization: the movement of people from rural areas to cities

16. Section Two: Changing Population Trends
A Demographically Diverse World
Demographers use the terms more developed and less developed
Least developed countries: show few signs of development and in some cases have increasing death rates, while birth rates remain high.
May be given priority for foreign aid

17. Section Two: Changing Population Trends
Managing Development and Population Growth
Many countries such as China and India have tried to reduce birth rates through public advertising, family planning, economic incentives, or legal punishments

18. Section Two: Changing Population Trends
Growth is Slowing
Current human population= 7.3 billion
Fertility rates are declining
Projections for 2050
World population of about 9 billion by 2050