1. The Human Population and Urbanization
Chapter 6

2. How Many people can the earth support?
Section 6-1
How Many people can the earth support?

3. Human Population Growth

4. Human population growth continues but it is unevenly distributed
Reasons for this increase in growth rate include:
Humans have expanded into almost all of the planet’s climate zones and habitats.
The emergence of early and modern agriculture allowed us to grow more food for each unit of land area farmed.
Death rates dropped sharply because of improved sanitation and health care.
Know this!!

5. Birth rates have decreased
In 2012 the average global birth rate was births per 1,000 total population, compared to per 1,000 total population in 2007.

6. This means that the human population increase is based on decreased death rate and not increased birth rate!

7. Because of the decreased death rate the number of elderly people continues to increase.

8. Human population growth continues but it is unevenly distributed
While the population is increasing - the rate of population growth has slowed!

9. Annual growth of world population, 1950-2011

10. What factors influence the size of the human population?
Section 6-2
What factors influence the size of the human population?

11. The human population can grow, decline, or remain fairly stable
Birth rate
Death rate
Immigration - Coming
Emmigration - Leaving
Population change of an area = (births + immigration) - (deaths + emigration)
Know this!!

12. Women are having fewer babies but not few enough to stabilize the world’s population
The total fertility rate (TFR) is the average number of children born to women in a population during their reproductive years.
Between 1955 and 2011, the average TFR dropped from 5 to 2.5.

13. Total fertility rates for the US between 1917-2011
A TFR of 2.1 will eventually halt the world’s population growth.

14. Baby boom (1946–64) Replacement level
4.0
3.5
3.0
Births per woman
2.5
2.1
2.0
1.5
Baby boom (1946–64)
Replacement level
1.0
0.5
1920
1930
1940
1950
1960
1970
1980
1990
2000
2010
Figure 6.3: The top graph shows the total fertility rates for the United States between 1917 and 2010 and the bottom graph shows the country’s birth rate between 1917 and Question: The U.S. fertility rate has declined and remained at or below replacement levels since So why is the population of the United States still increasing? (Data from Population Reference Bureau and U.S. Census Bureau)
Year
Fig. 6-3, p. 98

15. How does a population’s age structure affect its growth or decline?
Section 6-3
How does a population’s age structure affect its growth or decline?

16. A population’s age structure helps us to make projections
Age structure is the numbers or percentages of males and females in young, middle, and older age groups in a given population.

17. Population age-structure diagrams are made by plotting the percentages or numbers of males and females in the total population in each of three age categories:
Prereproductive (0–14): normally too young to have children.
Reproductive (15–44): normally able to have children.
Postreproductive (45+): normally too old to have children

18. Generalized population age-structure diagrams
Make sure you understand how to read these diagrams.

19. Less-developed Countries More-developed Countries
Male
Female
Male
Female
Male
Female
Male
Female
Expanding Rapidly Guatemala, Nigeria Saudi Arabia
Expanding Slowly United States Australia, China
Stable
Japan, Italy Greece
Declining
Germany, Bulgaria Russia
Active Figure 6.7: This chart represents the generalized population age-structure diagrams for countries with rapid (1.5–3%), slow (0.3–1.4%), zero (0–0.2%), and negative (declining) population growth rates. A population with a large proportion of its people in the prereproductive age group (far left) has a significant potential for rapid population growth. See an animation based on this figure at Question: Which of these diagrams best represents the country where you live? (Data from Population Reference Bureau)
Prereproductive ages 0–14
Reproductive ages 15–44
Postreproductive ages 45–85+
Fig. 6-7, p. 102

20. CASE STUDY: The American baby boom
Added 79 million people to the U.S. population
The large numbers of baby boomers have strongly influenced the U.S. economy. First they created a youth market and are now creating the late middle age and senior markets.
As the baby boomers turn 65, the number of seniors will grow sharply through This process has been called the graying of America.

21. As the number of working adults declines in proportion to the number of seniors, so will the tax revenues necessary for supporting the growing senior population.

22. The baby-boom generation in the US, 1955, 1985, and 2035

23. What are the implications of an aging population?
Sudden population declines

24. Rapid population decline can cause several problems

25. Some Problems with Rapid Population Decline
Can threaten economic growth
Labor shortages
Less government revenues with fewer workers
Less entrepreneurship and new business formation
Less likelihood for new technology development
Figure 6.9: Rapid population decline can cause several problems. Question: Which three of these problems do you think are the most important?
Increasing public deficits to fund higher pension and health-care costs
Pensions may be cut and retirement age increased
Fig. 6-9, p. 103

26. How can we slow human population growth?
Section 6-4
How can we slow human population growth?

27. There are three effective ways to slow population growth
The three most effective ways to slow or stop population growth are:
Reduce poverty
Elevate the status of women
Encourage family planning and reproductive health care.
Know this!

28. What are the major urban resource and environmental problems?
Section 6-5
What are the major urban resource and environmental problems?

29. Scientists see three important urban trends
Three major trends in urban population dynamics have emerged:
The proportion of the global population living in urban areas increased from 2% in 1850 to 50% today, and is projected to be 70% by 2050.
The numbers and sizes of urban areas are mushrooming.
Poverty is becoming increasingly urbanized, mostly in less-developed countries.

30. Major urban areas throughout the world – city lights at night

31. This phenomenon is known as urban sprawl.

32. Characteristics of Urban Sprawl
Reliance on automobiles
Fast food restaurants
Low pedestrians areas
Single use zoning – (residential, business, etc.)
Low density zoning – (one/two story homes with large yards)
Job Spawl
Shopping malls, strip malls, subdivisions.
Know this!

33. Urban Sprawl in different places
- Toronto
Mexico City -

34. Urban areas in the US with more than 1 million people

35. Urban sprawl in and around Las Vegas, NV, 1973 and 2009

36. Urban sprawl gobbles up the countryside
Urban sprawl is eliminating surrounding agricultural and wild lands.
Urban sprawl is the product of affordable land, automobiles, relatively cheap gasoline, and poor urban planning.

37. Urban sprawl gobbles up the countryside
Urban sprawl has caused or contributed to a number of environmental problems.
People are forced to drive everywhere, resulting in more emission of greenhouse gases and air pollution.
Sprawl has decreased energy efficiency, increased traffic congestion, and destroyed prime cropland, forests, and wetlands.
Sprawl has led to the economic deaths of many central cities as people and businesses move out.

38. Urban sprawl

39. Make sure you understand the problems of Urban Sprawl.

40. Urbanization has advantages
Cities are centers of industry, commerce, transportation, innovation, education, technological advances, and jobs.
Urban residents in many parts of the world tend to live longer than do rural residents, and have lower infant mortality and fertility rates.
Cities provide better access to medical care, family planning, education, and social services.

41. Urbanization has disadvantages
Most urban areas are unsustainable systems.
Most cities lack vegetation.
Many cities have water problems.

42. Urban areas are rarely sustainable systems

43. Cities tend to concentrate pollution and health problems
Cities produce most of the world’s air pollution, water pollution, and solid and hazardous wastes.
High population densities can increase the spread of infectious diseases, especially if adequate drinking water and sewage systems are not available.

44. Cities affect local climates
Cities tend to be warmer, rainier, foggier, and cloudier.
Heat generated by cars, factories, furnaces, lights, air conditioners, and heat-absorbing dark roofs and streets creates an urban heat island surrounded by cooler suburban and rural areas.
The artificial light created by cities affects some plant and animal species.

45. How does transportation affect urban environmental impacts?
Section 6-6
How does transportation affect urban environmental impacts?

46. Asia
Transportation in many Asian Countries

47. U.S.
Transportation in the U.S.

48. Motor vehicles advantages
They provide mobility and offer convenient and comfortable transportation.
They can be symbols of power, sex appeal, social status, and success.
Much of the world’s economy is built on producing motor vehicles and supplying fuel, roads, services, and repairs for them.

49. Alternatives to cars

50. How can cities become more sustainable and livable?
Section 6-7
How can cities become more sustainable and livable?

51. Smart Growth
Smart growth encourages environmentally sustainable development requiring less dependence on cars, controls and directs sprawl, and reduces wasteful resource use, by using zoning laws and other tools to channel growth into areas where it can cause less harm.

52. New Urbanism
New urbanism involves less-developed villages within cities, so that people can live within walking distance of where the work, shop, and go for entertainment.
New urbanism in Florida.
Seaside -
Celebration

53. Seaside, Fl

54. Smart growth tools

55. CASE STUDY: Curitiba, Brazil