1. Chapter 8 Human Population
Mr. Manskopf
Notes also at

2. Chapter 8 Big Idea
The size and growth rate of human population has changed drastically over the last 200 years. Those changes have led to profound changes to almost every place on Earth.

3. China’s One-Child Policy
In 1970, the average Chinese woman had about six children.
Since 1979, China has used a system of rewards and punishments to enforce a one-child limit to slow population growth.
In 2005, there were 32 million more males than females in China under the age of 20
Talk About It Is it ethical for governments to limit or encourage human population growth?

4. Studying Human Populations
Describe how the size and growth rate for human population has changed over history
What factors lead to population changes
Analyze populations using Age Structure Diagrams
Terms: Demography, Age Structure, Survivorship, Fertility, Migration, Life Expectancy

5. Describe what you see on this graph
How long did it take to get to 1 billion, than 2, 3,4,5,6
How many people are living today?
Did You Know? Basic sanitation was rare even in the medical profession until 1861, when Dr. Ignaz Semmelweis discovered that doctors’ hand washing greatly reduced patient mortality.

6. Why did it take so long to reach 1 billion?
Why do you think it took off around the late 1880s?
Interesting Fact: Of all the humans ever born, approximately 6-7% are alive today.

7. Studying Human Populations
Demography: the study of human population
How many people live where?
How long are you expected to live?
How many children are you likely to have.

8. Demography • Population size: Number of people
Population density: Number of people living per mi2 (or per km2)
Population distribution: How people are distributed within an area

9. Exponential Growth
Exponential Growth: rapid growth often seen as J-Shaped curve on a graph
Can that growth continue?

10. Forecasting Population Size
Will new schools be needed?
Should we be building more housing?
Should farming practices be improved?
Predictions like this often wrong because human behavior changes

11. Forecasting Population Size
Age Structure: the distribution of ages in a population
Age Structure Diagrams aka population pyramids
What is useful about these diagrams?

12. What are these age-structure diagrams showing?
What are the “reproductive years” Why is that important in forecasting future population growth?

13. Which “type” of countries are going to see most of the population growth?
Which “type” of countries do people live longer lives?
Survivorship: percent of population likely to survive a given age

17. What causes population to rise?
Changes =
(births + immigration) – (deaths + emigration)
For world population growth we are only concerned about births and deaths.

18. Fertility Rates
Fertility Rates: number of babies born each year per 1,000 women
Total fertility rate
Replacement rate fertility

19. Fertility and Women Two main factors impact fertility rates worldwide
Education level of women (knowledge of family planning)
Economic level of women
Generally, on average, more education, more wealth = lower fertility rates

20. How has U.S. fertility rates changed?
What does this graph show?
How has U.S. fertility rates changed?

21. Migration: movement INTO (immigration) or OUT of (emigration) an area
Population
Change =
(births + immigration) – (deaths + emigration)
Migration: movement INTO (immigration) or OUT of (emigration) an area
U.S. growth continues because of both births and immigration

22. Death rates on the decline… people living longer
Population
Change =
(births + immigration) – (deaths + emigration)
Death rates on the decline… people living longer
Why?
Better hygiene, sewage disposal, clean water, medicines, education, access to food, nutrition

23. Life Expectancy
Life Expectancy: average number of years members of a population are expected to live
Improvement in most of world
Lower INFANT MORTALITY

24. Compared to our neighbors

25. Major changes in U.S. over last 100+ years

26. Demographic Transition Every Country Goes Through It
Explain what you see on this chart

27. DESCRIBE EACH STAGE: WHAT DO YOU SEE?
Stage 1 : High Birth AND Death rates = little population change
Stage 2 : Death Rates Fall, Birth Rates Still High = Population Growth
Stage 3: Death Rates Low, Birth Rates Drop = Population Growth Slows
Stage 4: Death Rates Low, Birth Rate Low = Population Declines
DESCRIBE EACH STAGE: WHAT DO YOU SEE?

28. Calculations
A town currently has a population of 20 people. If 10 people are born, 8 people die, 3 immigrate and 1 emigrate, what is the population?

29. Calculations
USA currently has a population of 320,000,000 people. If 5,000,000 people are born, 2,000,000 people die, 200,000 immigrate and 50,000 emigrate, what is the population?

30. Rule of 70: Doubling Time
Currently, a city has a population 10 million. When will it reach 20 million if the population is growing at 10%?
How long will it take a population to go from 200 to 400 if it grows at 5% a year?

31. Review
Describe how the size and growth rate for human population has changed over history
What factors lead to population changes
Analyze populations using Age Structure Diagrams
Terms: Demography, Age Structure, Survivorship, Fertility, Migration, Life Expectancy

32. Population Age Structure
Rapid Growth
Guatemala
Nigeria
Saudi Arabia
Slow Growth
United States
Australia
Canada
Male
Female
Zero Growth
Spain
Austria
Greece
Negative Growth
Germany
Bulgaria
Sweden
Fig p. 184

34. Population Trends
What are problems associated with rapid human population growth?
Compare developed and developing (lesser developed) countries.
Investigate strategies for reducing population growth.
Terms: arable land, urbanization, suburban sprawl, developed and developing countries.

35. Problems With Rapid Growth
Lack of infrastructure to support population
Water supplies
Sewers
Roads
Schools
Powerplants
Hospitals
Housing

36. Problems With Rapid Growth
Using up resources too quickly
Water supplies
Food Supplies, Vegetation
Wood/fuels : wood supplies critical to life in many regions

37. Problems With Rapid Growth
Unsafe water supplies
Sewage mixing with water supplies
Cholera, Dysentery, Typhoid
1 Billion lack clean water
3 million/yr die

38. Clean Water Lacking
If the millions of women who haul water long distances had a faucet by their door, whole societies could be transformed.

39. Problems With Rapid Growth
Land becomes scarce
Arable land : land that can grow crops
Tradeoffs made : agriculture, housing, natural habitats
Which do you think typically wins out?

40. Problems With Rapid Growth
Urbanization: movement of people from rural areas to cities
Much of world is going through
Increased demand on infrastructure

41. Problems With Growth In U.S.
Suburban sprawl: work in cities live in suburbs
Decay of inner cities
Increased traffic
Loss of farmland
Decreased wildlife habitat

42. Suburban Sprawl

43. Diverse World Population
Developed Countries
US, Canada, Japan, Australia, New Zealand and most of Europe. High Per Capita GDP. (1.2 billion people)

44. Comparing a developed countryto
Moderately Developed
Developing (lesser developed)
Did You Know? On average, 1 American consumes as much natural resources as 5 Chinese or 13 Pakistanis.

45. Diverse World Population
Developing (lesser developed)
5.2 billion people
living with very little
97% of population growth.

46. Percent of World’s 19 Population 81 0.1 Population growth 1.6 85
Wealth and income 85 15 88
Resource use 12 75
Pollution and waste 25
Developed countries
Developing countries

48. Most fertility rates are dropping toward replacement levels

49. Strategies for Controlling Growth
Public Advertisements
Economic Incentives
Legal Punishments
Empowering Women
Investments in Education and Family Planning

50. Growth Is Slowing but still growing

51. Review
What are problems associated with rapid human population growth?
Compare developed and developing (lesser developed) countries.
Investigate strategies for reducing population growth.
Terms: arable land, urbanization, suburban sprawl, developed and developing countries.