1. Studying Human Populations
A public beach in China. China has one of the largest populations in the world with more than 1 billion people

2. Studying Human Population
Demography – the study of populations
The historical size and makeup of populations
Properties that affect population growth (economics & social structure)
Developed Countries = higher incomes, industrial economies, slower population growth
Developing Countries = lower incomes, agricultural economies, faster population growth

3. The Human Population Over Time
After growing slowly for thousands of years, the human population grew exponentially in the 1800s.
Why?
Increases in food production
Improvements in hygiene & medicine

4. The USA POPULATION DENSITY
RANK
STATE
POP. DENSITY 1 NJ
1205 pp/mi2 2 RI
1016 pp/mi2 3 MA
852 pp/mi2 4 CT
741pp/mi2 5 MD
606 pp/mi2 6 DE
471 pp/mi2 7 NY
415 pp/mi2 8 FL
360 pp/mi2 9 PA
285 pp/mi2 10 OH
282 pp/mi2

5. Forecasting Population Size
Age structure – distribution of ages in a specific population at a certain time.
Ex: if a population has more young people than old people, that the population will likely increase.
Population pyramid – graphs age structure

6. Forecasting Population Size
Survivorship – percentage of members of a group that are likely to survive to any given age.
Demographers study groups of people born at the same time and notes when these people die.
Type I survivorship curve = people live to be very old.
Type II survivorship curve = similar death rate at all ages
Type III survivorship curve = many people die young

7. Forecasting Population Size
Fertility Rates – the number of babies born each year per 1000 women in a population
Replacement level = the average number of children each parent must have to replace themselves in the population = 2.1 b/c not all children will survive & reproduce.
Total fertility rate in the United States. 

8. Forecasting Population Size
Migration – the movement of individuals between areas
Immigration = movement into an area
Emigration = movement out of an area
Population of the United States

9. Declining Death Rates
Death rates have declined more rapidly than birth rates because of:
an adequate amount of food resources
clean water
safe sewage disposal
vaccinations.
Life expectancy – average number of years a person is likely to live.

10. Women & Fertility
Increased education and economic independence for women = declining birth rates.
Why?
Learn family planning techniques
Do not need children to ensure survival
Contribute to family’s prosperity by working
Children are expensive in modern societies

11. Changing Population Trends
A rapidly growing population uses resources at an increased rate and can overwhelm the infrastructure of a community.
Infrastructure – basic facilities & services that support a community (water supplies, sewer lines, power plants, roads, schools, hospitals, etc.)

12. Problems of Rapid Growth
Shortage of Wood &/or Fuel
Unsafe &/or Limited Water Supplies
Land Impacts
Shortage of arable land – land that can be used for crops
Urbanization – movement of people into cities
Suburban sprawl – people living in suburbs, causing traffic jams, inadequate infrastructure, and reduction of land for farming or wildlife habitats

13. Which regions of the world will contribute the most population growth?

14. Managing Development & Population Growth
Less developed countries know that continued population growth can limit their economic development. Some countries have tried to reduce birth rates using:
-public advertising
-family planning programs
-economic incentives
-legal punishments

15. Growth is Slowing
Human population is more than 6 billion and increasing. If people worldwide practice replacement level reproduction, the population in 2050 will be around 9 billion. It will be much higher without planned reproduction.

16. USA Population Growth
US Population
1950 = 150,000,000
1998 = 270,000,000
By 2050 = 430,000,000
*How fast is the US
population increasing?
*What is causing this
growth?