1. The Human Population
Chapter 9

2. Section 1: Studying Human Populations

3. Studying Human Populations
Demography – the study of (ANY!!) population
But usually only human populations
Demographers (people who study populations) have two categories for countries - Developed and Non-Developed
Developed –
High incomes, slow population growth, lots of industry
Can you name one?
Non-Developed –
Low incomes, fast population growth, agriculture based economy
Studying Human Populations

4. Human Population Over Time
Exponential Growth – Rapid increase in a population
Due to better food production, medicine, hygeine
Can we sustain this growth?
Human Population Over Time

5. Forecasting Population Size
Age Structure diagrams – can give a forecast of future issues
Lots of children now, means a population increase in years when those kids start having kids.
Population Pyramids –
Two sided – male and female
Developed and Non-Developed countries have distinctive looking pyramids
Forecasting Population Size

7. Survivorship Curves – the percentage of that population that will survive at any given age
Type I – Few offspring, but they live a long time
Type II – Equal chance of living or dying every day
Type III – Most offspring die young with few surviving to older age

8. Fertility Rates: Number of babies born each year per 1000 women
Total fertility rate: average number of children a woman will give birth to in her lifetime
Replacement Level – The number of children a couple needs to have to replace themselves
In developed countries this is 2.1 (why the .1?)
Women are the biggest factor in controlling growth
Education (jobs and childcare leads to not needing as many children)
Birth Control
Population can also change due to:
Immigration – people moving in
Emmigration - people moving out
Death Rates are delining all over the world. Why?
Life expectency – the average number of years someone will live
Life expectency worldwide has risen to 67 years
Factors affecting life expectency
Contagious diseases, AIDS and tuberculosis

9. Demographic Transition Model
Phase 1 – Agrarian - high birth AND death rates
Phase 2 – Low death rates, high birth rate – POPULATION EXPLOSION
Phase 3 – Birth rate is declining but population is very large
Phase 4 – low birth AND death rates
Demographic Transition Model

10. Time for a reading quiz
That’s all for 9.1

11. Section 2: Changing Population Trends

12. Problems of Rapid Growth
Infrastructure: basic facilities/services that support a community
Public water, sewer, roads, hospitals, power plants
Shortage of fuel wood
Clean water, heat, and edible food come from a reliable heat source
Expanding populations increase need/decrease availability of fuel wood
Unsafe Water
No sewers or water treatment plants
Water sources (rivers) used for drinking, cooking, washing, AND sewage
1 billion people unsafe water worldwide/ 3 million died of water diseases
Right here in US – Rio Grande river in Texas

13. Problems of Rapid Growth
Land Impacts
Arable Land –land where crops can grow
More people need homes leads to less arable land
Less arable lands leads to less food grown.
Less food + more people = starvation
Urbanization – people moving from rural to city
Suburbs – sprawl, still taking up arable land
Harsh environments –people live near resources - Egypt
Problems of Rapid Growth

14. Not all countries are following the demographic transition model
Some industry, but still low incomes
High education, but low industry
Least Developed Countries – a focus of world community and United Nations
Still have high death rates, high birth rates, and little industry
Diverse World

15. Population growth is slowing
Countries working to slow population growth because of demands on environment and resources
China – One Child Policy
Family planning policies
Financial Incentives
Improving status of women
Population growth is slowing
We just hit 7 BILLION people

16. Time for a reading quiz
That’s all for 9.2