1. The Human Population and Its Impact
Chapter 6

2. Core Case Study: Are There Too Many of Us? (1)
Estimated 2.4 billion more people by 2050
Are there too many people already?
Will technological advances overcome environmental resistance that populations face?
Should populations be controlled?

3. Core Case Study: Are There Too Many of Us?
Will growing populations cause increased environmental stresses?
Infectious diseases
Biodiversity losses
Water shortages
Traffic congestion
Pollution of the seas
Climate change

4. 6-1 How Many People Can the Earth Support?
Concept 6-1 We do not know how long we can continue increasing the earth’s carrying capacity for humans without seriously degrading the life-support system for humans and many other species.

6. Human Population Growth Continues but It Is Unevenly Distributed
Reasons for human population increase
Movement into new habitats and climate zones
Early and modern agriculture methods
Control of infectious diseases through
Sanitation systems
Antibiotics
Vaccines

7. Human Population Growth Continues but It Is Unevenly Distributed (2)
Population growth in developing countries is increasing 15 times faster than developed countries
By 2050, 97% of growth will be in developing countries
Should the optimum sustainable population be based on cultural carrying capacity?

8. MI L I O NS

9. Population Projections
Over 95% of this increase
will take place in “Developing
Countries”

11. Current World Population
Population Clock Vital Events (per time unit)
Global population was 6,901,260,547 US population- 310,859,059
On Feb. 20th 2011at 9:30 pm
The global population grows by:
Nearly 2.4 persons per second
Nearly 8,607 persons per hour
Over 206,563 persons per day
Over 75 million persons per year
Us. Population 308 million exactly 308,782,965 as of march 1st 2010

12. How Much is a Billion? 1,000 seconds = 16.7 minutes
1 million-s = 16,677 min = 11.6 days
1 billion-s = 11,574 days = 31.7 years
1,000 pennies = ~ 88 ounces = 5.5 pounds
1 million pennies = 5,500 pounds (~1-Suburban)
1 billion pennies = 2,750 tons (~2 Space Shuttles)

13. Billion Grains of Rice 200 grains of rice in a teaspoon
9,600 grains of rice in a cup (48 tsp)
How many Cups are in a Gallon?
16 cups
How many grains of rice are in 16 cups?
9,600 x 16 = 153,600 grains of rice
How many gallons would it take to take to equal 1 million grains of rice?
1,000,000 divided by 153,600 =
6.5 Gallons = 1 million grains of rice

14. If 6.5 gallons equal 1 million how many gallons would it take to equal 1 billion?
6.5 gallons x 1000 =
6,500 gallons = 1 billion
How many gallons would it take to equal 6.6 billion?
42,900 gallons of rice = 6.6 billion grains of rice.

15. Science Focus: How Long Can the Human Population Keep Growing?
Thomas Malthus and population growth: 1798
Humans have altered 83% of the earth’s land surface
Can the human population grow indefinitely?
Thomas Malthus published his famous Essay on Population in 1798 predicting that humanity was doomed to poverty and famine because the human population was growing exponentially, while mankind’s ability to produce food could only increase at a linear rate.
He wrote at a time when the famous curve of human population growth was way down here. The ensuing science-based increases in agricultural production supported a tripling of the human

16. 6-2 What Factors Influence the Size of the Human Population?
Concept 6-2A Population size increases because of births and immigration and decreases through deaths and emigration.
Concept 6-2B The average number of children born to women in a population (total fertility rate) is the key factor that determines population size.

17. The Human Population Can Grow, Decline, or Remain Fairly Stable
Population change
Births: fertility
Deaths: mortality
Migration
Population change =
(births + immigration) – (deaths + emigration)
Crude birth rate- # births / 1000 population
Crude death rate- # deaths / 1000 population

20. Rates of Global Pop. Change use: International Data Base http://www
Rates of Global Pop. Change use: International Data Base then Online Demographic Aggregation
CBR (crude birth rate) = # births / 1000 population
1990: 24 now: 20.6
CDR (crude death rate) = # deaths / 1000 population
1990: 9 now: 8.8

21. Growth Rate = (b + i) – (d + e)
1990: 1.5% now: 1.19%
growth rates have come down
Annual rate of Natural Population change % = (BR – DR/1000) x 100
(BR-DR)/10

22. Rule of 70 How long does it take to double? Rule of 70 Resource use
Population size
Money in a savings account
Rule of 70
70 divided by the percentage growth rate = doubling time in years
70 / 7% means it takes ten years to double
Homework: YouTube- rule of 70- Albert Bartlett
“Most important video you will ever see” 9 min.

23. Women Having Fewer Babies but Not Few Enough to Stabilize the World’s Population
Replacement fertility rate (RFR)
The number of children a couple must have to replace their parents
A RFR of 2.1 for developed countries with low infant and child mortality rates
Africa RFR = 2.5
Total fertility rate (TFR)
The average number of children born to a woman
Average in developed countries = 1.5
Average in developing countries = 3.8
Worldwide 1990: 3.1 now: 2.76

25. Total Fertility Rates for US
4.0
3.5
3.0
2.5
Births per woman
2.1
2.0
1.5
Baby boom
( )
Replacement
level
1.0
Baby boom started at the end of WWII
0.5
1920
1930
1940
1950
1960
1970
1980
1990
2000
2010
Year

26. Case Study: The U.S. Population Is Growing Rapidly
Drop in TFR in U.S.
Rate of population growth has slowed
Population still growing and not leveling off
Fourfold increase since 1900
Changes in lifestyle in the U.S. during the 20th century

27. Several Factors Affect Birth Rates and Fertility Rates
Children as part of the labor force
Cost of raising and educating children
Availability of private and public pension
Urbanization
Educational and employment opportunities for women

28. Several Factors Affect Birth Rates and Fertility Rates
Infant mortality rate
Average age of a woman at birth of first child
Availability of legal abortions
Availability of reliable birth control methods
Religious beliefs, traditions, and cultural norms

29. Homes with flush toilets 98%
47 years
Life expectancy
77 years
Married women working
outside the home 8%
81%
15%
High school graduates
83%
10%
Homes with flush toilets
98% 2%
Homes with electricity
99%
10%
Some major changes that took place between 1900 and Data from U.S. Bureau of the Census and department of Commerce.
Living in suburbs
52%
1900 $3
Hourly manufacturing job
wage (adjusted for inflation)
2000
$15
1.2
Homocides per
100,000 people
5.8

30. Several Factors Affect Death Rates
Life expectancy
Average # of years a newborn
can expect to live
Infant mortality rate (IMR)
infant deaths per 1000 live
births (infant < 1 yr)
Why are people living longer
and fewer infants dying?
Increased food supply and distribution
Better nutrition
Medical advances
Improved sanitation

31. Several Factors Affect Death Rates (2)
U.S. infant mortality rate high due to
Inadequate health care for poor women during pregnancy and their infants
Drug addiction among pregnant women
High birth rate among teenagers

32. http://www. povertymap

33. Migration Affects an Area’s Population Size
Economic improvement
Religious freedom
Political freedom
Wars
Environmental refugees

34. Case Study: The United States: A Nation of Immigrants
Historical role of immigration in the U.S.
Opportunity for the world’s poor and oppressed
Since 1820, the U.S. has admitted almost twice as many immigrants and refugees as all other countries combined
Legal immigration
Illegal immigration
Legal and illegal immigration accounts for 40% of the country’s annual population growth

36. 6-3 How Does a Population’s Age Structure Affect Its Growth or Decline?
Concept 6-3 The numbers of males and females in young, middle, and older age groups determine how fast a population grows or declines.

37. Population Pyramids Graphic device: bar graph
shows the age and gender composition of a region
horizontal axis: gender
male: left-hand female: right-hand
absolute number of people or %
vertical axis: age groups
Pre-reproductive ages = birth –14 years of age
Reproductive ages= 15 –44 years of age
Post reproductive ages = 45 & up

38. Population Pyramid with young cohorts

39. Population Pyramids High Growth: Afghanistan
Population Pyramids on the Web
High Growth: Afghanistan
Moderate Growth: Mexico
Zero Growth: U.S.
Negative Growth: Austria or Italy

41. Population Pyramids Moderate Growth: Mexico
Population Pyramids on the Web
High Growth: Afghanistan
Moderate Growth: Mexico
Zero Growth: U.S.
Negative Growth: Austria or Italy

43. Population Pyramids Zero Growth: U.S. Population Pyramids on the Web
High Growth: Afghanistan
Moderate Growth: Mexico
Zero Growth: U.S.
Negative Growth: Austria or Italy

45. Population Pyramids Negative Growth: Italy
Population Pyramids on the Web
High Growth: Afghanistan
Moderate Growth: Mexico
Zero Growth: U.S.
Negative Growth: Italy

47. We Can Use Age-Structure Information to Make Population and Economic Projections
Baby boomers
Job market when they retire

48. Influencing Population Size Age Structure & Population Projections
Baby boomers - half of U.S. population; use most of goods and services; make political and economic decision
baby-bust generation - born since 1965; may have to pay more income, health care and social security to support retired baby boomers; but face less job competition
Better health may --> later retirement of baby boomers --> keep high-salary jobs

49. Tracking the baby-boom generation in the United States

50. Populations Made Up of Mostly Older People Can Decline Rapidly
Slow decline
Manageable
Rapid decline
Severe economic problems
Severe social problems

51. Effects of Population Decline
As percentage of 60+ aged people increases, population begins decline
60+population increase --> severe economic and social problems because 60+ consume
more medical care
Social Security
costly public services
Labor shortages require automation & immigration

53. The Graying of Japan
Family-planning access, cramped housing, expensive land, late marriage, education cost --> voluntary decrease in birth rate
Low immigration rate
Health insurance and pension - 45% of national income; could -->low economy
Illegal immigration bolsters work force

54. Populations Can Decline from a Rising Death Rate: The AIDS Tragedy
25 million killed by 2008
Many young adults die: loss of most productive workers
Sharp drop in life expectancy
International community called upon to
Reduce the spread of HIV through education and health care
Financial assistance and volunteers

55. 6-4 How Can We Slow Human Population Growth?
Concept 6-4 Experience indicates that the most effective ways to slow human population growth are to encourage family planning, to reduce poverty, and to elevate the status of women.

56. As Countries Develop, Their Populations Tend to Grow More Slowly
Demographic transition stages
Preindustrial AKA Pre Transition
Transitional AKA Early Transitional
May lead to a demographic trap
Industrial AKA Middle Transition
Postindustrial AKA Late Transition

57. http://www. geographyalltheway

58. The Demographic Transition
                                                                                                                                                                

59. Five Stages of the Demographic Transition
Used to be 4, now 5 stages
birth rates, death rates and growth rates systematically change through time as societies change:
modernize, urbanize
gain access to technology

60. Stage 1- Pre-transition or Pre-industrial stage
high birth rates, high (at time erratic) death rates, low growth rates
stage for much of human history, traditional societies
practically no country today

61. Stage 2- Early Transition or Transitional
high birth rates,
declining death rates,
rising growth rates
improvements in
sanitation (water)
and medicine
in Europe during Industrial Revolution
in developing countries since the 50s/60s
much of Africa today, some countries of Asia (Afghanistan, Nepal, etc.)

62. Stage 3- Middle Transition or Industrial stage
continued decline of death
rates, declining birth rates,
growth rates decline from
high to lower levels
change in behavior: adaptation to lower death rate, in particular infant mortality rate
economic change: urbanization (incentive to have fewer children)
Mexico today

63. Stage 4- Late Transition or Postindustrial stage
Stage 4: low birth rates,
low death rates, low
growth rates
United States today
Stage 5: low birth rates, rising death rates, declining growth rates (if birth rates drop below death rates: negative growth rates)
several countries of Europe today (Austria)
Stage 5-

64. Link to Population Pyramids?

65. Planning for Babies Works
Family Planning
Responsible for a 55% drop in TFRs
In developing countries
Expansion of program
Include teenagers, sexually active unmarried women, and men
Slow and stabilize population growth
Invest in family planning
Reduce poverty
Elevate the social and economic status of women

66. What Is Family Planning?
Definition
Measures enabling parents to control number of children (if they so desire)
Goals of Family Planning
Not to limit births
For couples to have healthy children
For couples to be able to care for their children
For couples to have the number of children that they want

68. What Methods are Used to Control Births?
Preconception Birth Control Methods
Barrier Methods
Condom
Vaginal sponge
Diaphragm
Spermicides
Hormonal Contraceptives
Pill
Injections and implants
Sterilization
Postconception Birth Control Measures
Intrauterine Device
RU-486 Pill
Abortion

69. Typical effectiveness rates of birth control methods in the U.S.
Extremely Effective
Total abstinence
100%
Sterilization
99.6%
Vaginal ring
98-99%
Highly Effective
IUD with slow-release
hormones
98%
IUD plus spermicide
98%
Vaginal pouch
(“female condom”)
97%
IUD
95%
Condom (good brand)
plus spermicide
95%
Oral contraceptive
93%

70. Typical effectiveness rates of birth control methods in the U.S.
Cervical cap
89%
Condom (good brand)
86%
Diaphragm plus
spermicide
84%
Rhythm method (Billings,
Sympto-Thermal)
84%
Vaginal sponge impreg-
nated with spermicide
83%
Spermicide (foam)
82%

71. Typical effectiveness rates of birth control methods in the U.S.
Moderately Effective
Spermicide (creams,
jellies, suppositories)
Rhythm method (daily
temperature readings)
75%
74%
Withdrawal
74%
Condom (cheap brand)
70%
Unreliable
Douche
40%
Chance (no method)
10%

72. Contraceptive Use Worldwide
People in industrialized countries enjoy easy access to contraceptives while those in LDCs do not.
In the U.S., teens and poor women are least likely to use contraceptives.
Severe problems are associated with teen pregnancy.
Teens don’t receive the care they need.
More adolescent girls die from pregnancy-related causes than any other cause.
Maternal mortality is twice as high for women younger than 20, and 4 times as high for women younger than 17.
Each year about 15 million young women ages have babies.
Survival rate for babies born to teens is low.
Young age of mother can cause problems with the child.
Teen pregnancy causes greater public expenditures.

73. Empowering Women Can Slow Population Growth
Education
Paying jobs
Human rights without suppression
“For poor women the only holiday is when you are asleep”

74. Empowering women to reduce births
Women tend to have fewer, and healthier children when:
they have access to education and paying jobs outside home
their society doesn’t suppress women’s rights
But women do most of the work
not shown in GDP because of lower pay
Women excluded from economic and political decision making

75. Typical workday for a women in Rural Africa
4:45 A.M.
Wake,
wash, and
eat
5:00 A.M.-
5:30 A.M.
Walk to
fields
5:30 A.M.-
3:00 P.M.
Work in
fields
3:00 P.M.-
4:00 P.M.
Collect
firewood
4:00 P.M.-
5:30 P.M.
Pound and
grind corn
5:30 P.M.-
6:30 P.M.
Collect
water
6:30 P.M.-
8:30 P.M.
Cook for
family and
eat
8:30 P.M.-
9:30 P.M.
Wash
dishes
and children
9:30 P.M.
Go to bed

76. Case Study: Slowing Population Growth in China: the One-Child Policy
Encourages fewer children
Gender imbalance
Fast-growing economy
Face serious resource and environmental problems

77. Case Studies - China
Family planning efforts began in 1970; TFR fell from 5.7 to 1.8; infant mortality and illiteracy rates 1/3 to 1/2 of India’s rates
Population control program is extensive, intrusive and strict:
postpone childbearing
only one child/family -->benefits
effect b/c China is dictatorship; limited resources would have meant disaster

78. China’s Program
Nation With Best Known Population Control Program
Reasons Chinese Government Initiated Population Control Measures
Freshwater and food at a premium for nation’s population
Country experiencing population momentum
Government Perks / Coercive Measures for Citizen Compliance
Free education and health care
Increased personal and family incomes
Increased legal marrying age for women
Contraceptives, abortions, and sterilizations free of charge
Preferential housing and retirement income

79. Case Study: Slowing Population Growth in India
Population control: gender bias
Poverty
Malnutrition
Environmental problems

80. Case Studies - India
Family planning efforts began in 1952; fertility rate declined from 5.3 to 3.4 but population grow is still exponential -1.9%
Disappointing results due to:
poor planning
bureaucratic inefficiency
low status of women
extreme poverty
lack of administrative & financial support