1. The Human Population and Its Impact
Chapter 6

2. 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 :
 Death Rate

3. 10,000 yrs ago- 5 million 1930- 2 billion 1975 – 4 billion 2011 – 7 billion 2050 – 9.5 billion

4. UN World Population Projections by 2050
2.5 children
2.0 children
World population is growing exponentially at a rate of 1.21%
1.5 children
The prospect of stabilization in the near future is nil.
We are moving from a J-Curve to an S-curve

5. What does a 1.21% growth rate mean?
There were about 83 million people added to the earth in 2010
Which is about 227,000 people every day
Which is 2 more people every time your heart beats

6. 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? Optimum level that allows people to live in reasonable comfort and freedom and still have sustainability

8. How Long Can the Human Population Keep Growing?
Thomas Malthus and population growth: 1798 (Populations increase exponentially , food supply increases linearly. Wrong!! Actually-food-exponentially due to genetic and technological advances)
Humans have altered 83% of the earth’s land surface
Can the human population grow indefinitely?

9. What is really the problem?
Overpopulation? This is degrading our planet. (82% of population is in less developed nations)
Overconsumption? Americans ecological footprints are 4.5X larger than the average Chinese and 9.5 times larger than the average Indian
Technology? These advances have helped eliminate environmental resistances
How do we alter nature?

11. Current and projected population sizes by region

12. The World’s 10 Most Populous Countries in 2008

13. Resources depletion and degradation

14. 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=# of live births per 1000 people in a population
Crude death rate=# of deaths per 1000 people in a population

15. Women Having Fewer Babies but Not Few Enough to Stabilize the World’s Population
Fertility rate- # of children born to a woman during her lifetime
Replacement-level fertility rate- avg. # of kids that a couple must bear to replace themselves.
2.1 developed-2.5 in developing Total fertility rate (TFR)- avg. # of kids born to a woman during reproductive years.
TFR in 2010:
1.7 per woman in developed countries
2.7 per woman in developing countries

16. In 2010, TFR in developing countries dropped from 6. 2 to 2
In 2010, TFR in developing countries dropped from 6.2 to 2.7 and in developed countries, from 2.8 to 1.7
In China, the TFR dropped from 5.7 to 1.5 (from )

17. Birth Rates in the U. S. from 1910 to 2008 baby boom TFR= 3
Birth Rates in the U.S. from 1910 to 2008 baby boom TFR= TFR= 2.1

18. Some Major Changes That Took Place in the U.S. between 1900 and 2000

19. Several Factors Affect Birth Rates and Fertility Rates
Children as part of the labor force
Cost of raising and educating children
Fact: : It costs to raise a child in the US from birth to 18.
Availability of private and public pension
Urbanization
Educational and employment opportunities for women-TFR is low as education 
$220,000

20. Several Factors Affect Birth Rates and Fertility Rates
Average age at marriage (the older they are when they marry, the fewer children they usually have)
Religious beliefs, traditions and cultural norms

21. Reducing Births PROS better than raising death rate
we already fail to provide basic necessities for one-fifth of the world
over pop. Is the main reason for environmental degradation and resource over consumption
technology is the key to economic power, not more people
freedom to reproduce should only apply if it does not reduce the quality of other peoples lives
CONS
*people live longer
*some people believe that the world can support millions more
*people are our most valuable resource

22. Several Factors Affect Death 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
Population increase is due to decline in crude death rate

23. Migration Affects an Area’s Population Size
Why migrate???
Economic improvement
Religious freedom
Political freedom
Wars
Environmental refugees-40 million in 2008, water and food shortage, drought

24. Several Factors Affect Death Rates
Life expectancy- globally, increased from 47 to 69 years from by 2050…74 years
Japan has longest life expectancy of 83 and US is 78 (50th of all nations)
Infant mortality rate- reflects country’s level of nutrition and health care
Why are people living longer and fewer infants dying?
Increased food supply and distribution
Better nutrition
Medical advances
Improved sanitation

25. Drug addiction among pregnant women High birth rate among teenagers
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

26. Legal Immigration to the U.S. between 1820 and 2003
Immigration Reform and Control Act of 1986: granted legal status to illegal immigrants if they showed they lived in the country several years.
Legal Immigration to the U.S. between 1820 and 2003

27. 36% of US growth is due to legal/illegal immigration
Many Americans believe all immigration should be reduced.

28. Opposition-
It would diminish the historical role of the US being a place of opportunity for the poor and oppressed
Take away cultural diversity
Most immigrants pay taxes, start new businesses and create jobs
Take menial and low paying jobs
Proponents-
Allow immigrants if they can support themselves
By lowering immigration, the US could stabilize its population and reduce its ecological footprint

29. Populations Made Up Mostly of Young People Can Grow Rapidly
Age structure categories
Pre-reproductive ages (0-14)
Reproductive ages (15-44)
Post-reproductive ages (45-over)
Males vs. females

30. Generalized Population Age Structure Diagrams
Nearly 27% of people on planet were under 15 in 2010

31. Population Structure by Age and Sex in Developing and Developed Countries

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

34. The Fastest Growing Age Group Is…
SENIORS!
The global populations of seniors is projected to triple by 2050 in which 1 of every 6 people will be 65 or older.
This graying of the population is due to declining birth rates and longer life expectancies due to medical advancements.

35. Populations Made Up of Mostly Older People Can Decline Rapidly
Slow decline
Manageable
Rapid decline-Japan, Russia, Germany, Hungary, Greece, Italy
Severe economic problems (less in work force, fewer children to care for grandparents, more spent on medical care, pension funds, and shortages of health-care workers

36. Number of workers supporting each Social Security beneficiary40
1945
41.9 workers 30 20
Number of workers supporting
each Social Security beneficiary
1950
16.5 10
2075
1.9
1945
2000
2050
2075
Fig , p. 249

37. Populations Can Decline from a Rising Death Rate: The AIDS Tragedy
27 million killed by 2009
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 to provide education, healthcare, teachers, social workers

38. Slowing the Human Population Growth
Demographic Transition: As countries become industrialized
Death rate declines
Then birth rate declines
4 majors stages…

39. Four Stages of the Demographic Transition

40. US is in the early phase of stage 4
Most of the less developed countries will make a demographic transition over the next few decades due to technology and family planning
Some fear these countries will stay in stage 2 due to extreme poverty, and rapid population growth. Many lack basic services such as food, health care and education. Countries are in civil war, and are training grounds for terrorist groups
Somalia- 3% population growth, TFR=6.5 and 45% of population under 15.
Haiti- foreign debt, lack of skilled workers, large number of people in poverty, and the 7.0 earthquake in Jan 2010

42. 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

43. Bangladesh- TFR dropped from 6.0 in 1960 to 2.7 in 2010.
Family planning and economic development are responsible for the drop.
Thailand’s TFR dropped from 6.4 to 1.8
The best way to slow and stabilize population growth are through
1. promoting economic development
2. elevating the social and economic status of women
3. Encouraging family planning

44. Empowering Women Can Slow Population Growth
Education-fewer children
Paying jobs
Human rights without suppression
“For poor women the only holiday is when you are asleep”
Women account for 2/3 of all hours worked, but only get 10% of world's income

45. 8:30 P.M.-
9:30 P.M.
Wash
dishes
and children
5:30 P.M.-
3:00 P.M.
Work in
fields
3:00 P.M.-
4:00 P.M.
Collect
firewood
6:30 P.M.-
8:30 P.M.
Cook for
family and
eat
9:30 P.M.
Go to bed
4:45 A.M.
Wake,
wash, and
eat
5:00 A.M.-
5:30 A.M.
Walk to
fields
4:00 P.M.-
5:30 P.M.
Pound and
grind corn
5:30 P.M.-
6:30 P.M.
Collect
water
Fig , p. 256

46. Women Make up 70% of the world’s poor
64% are illiterate (and 5-7 children)
60-80% of work associated with growing food, gathering wood and hauling wood and water
In most societies, they have fewer rights and educational and economic opportunities
(Sharbat Gula 1985 and 2002)
(Afghanistan refugee who crossed over into Pakistan)

47. Slowing growth in India
1952- the first national family planning program began
2nd largest population today, but projected to be the largest by 2015
32% of its population is under 15
4th largest economy, growing middle class
Faces poverty, malnutrition and environmental problems
¼ of urban population lives in slums
2/3 of population lives in rural areas
Nearly ½ are unemployed or underemployed
¾ live on less than $2.25 a day

48. Most poor couples believe they need several children to work and care for them in old age
Cultural preference for male children
Only 48% use some form of birth control
17% of world’s population, 2.3% of land and 2% of forests
Soil erosion and overgrazing of ½ of croplands
2/3 water is polluted
Sanitation often inadequate
Economic growth= larger ecologic footprint but possible a slower population growth

49. What does it mean to grow exponentially?
Youtube. The most important video you’ll ever see

50. Population Calculations
Global population
growth rate = CBR-CDR 10
If there were 20 people born per 1,000 people and deaths per 1,000, the global population growth rate would be 1.2%
In 2011, the population growth rate of the ….
world was 1.09%
Zimbabwe = 4.3%
Japan = -0.1%
US = 0.9%
China= 0.5%
India = 1.3%

51. To calculate the population growth rate for a single nation, we take immigration and emigration into account.
Nat. pop = (CBR + immigr) – (CDR+ emigr)
growth rate 10

52. Population Growth Rate
Annual world
population growth
<1%
1-1.9%
2-2.9%
3+%
Data not
available
Fig. 11.3, p. 240

53. If we know the growth rate of a population and assume that growth rate is constant, we can calculate the number of years it takes for a population to double. Doubling Time
Rule-of-70 - way to calculate the approximate number of years it takes for the level of a population growing at a constant rate to double.
States that the approximate number of years n for a variable growing at the constant growth rate of r percent, to double is:
n = 70/r

54. For example, a city with an annual population growth rate of 5% will double its population in approximately 14 years. 70 =14 5
If the growth rate were 7%, it would double its population in approximately ? years. 10

55. Remember that a population growing at 2 percent per year, regardless of the size will double in 35 years. Whether the population is 500,000 or 50,000, it will still double in the same amount of time.
It is almost certain that the Earth’s population will not double again. Most demographers believe that the human population will be somewhere between 8.1 billion and 9.6 billion in 2050 and stabilize by 2100.

56. New Zealand has a population of 4. 3 million people, a TFR of 2
New Zealand has a population of 4.3 million people, a TFR of 2.1 and a net migration rate of 2 per 1,000. How many people will New Zealand gain next year as a result of immigration? (assume the TFR and net migrations stays the same)
Net migration = # of immigrants
rate # of people in pop
A TFR of 2.1 for a developed country suggests that the country is at replacement-level fertility and thus the population is stable.

57. The migration rate suggest that
2__ = __ x_ _
,300,000
So, X= 8,600 people/year
Since there is no growth due to biological replacement and a net migration of 8,600 people, the rate of increase is
8,600 people/year = 0.2%
4,300,000 people
How many years will it take the population to double at this rate?

58. T= T= = 350 years
r /yr

59. A metropolitan region of 100,000 people has 2,000 births, 500 deaths, 200 emigrants, and 100 immigrants over a 1 year period. Calculate its population growth rate.
Net increase = 2,100
Net decrease= 700
Total change in population=
Total number in population = 100,000
= = 1.4%

60. In 2010, the population of Upper Fremont was 200,000 and growing at a rate of 2% each year.
If the rate of population growth remains constant, calculate the population in 2045.
Determine the doubling time of the population by dividing 70 by 2 to get 35 years. Since one 35-year period passes between 2010 and 2045, the population would have doubled once from 200,000 to 400,000.

61. The population of Lower Fremont was 20,000 in 1968
The population of Lower Fremont was 20,000 in In 2010 the population was 160,000. Assuming the growth is exponential, calculate the average annual percentage rate of population growth since 1968.
= 42 years
The population has doubled 3 times since ,000 → 40,000 → 80,000 → 160,000
42/3 = 14 years
T= 70/r and r= 70/t
70/14 = 5%

62. In 2010, the CBRin East Fremont was 25 and the CDR was 11
In 2010, the CBRin East Fremont was 25 and the CDR was 11. Calculate the percentage growth rate of East Fremont in If the population was 15,000 in 2010, and the population growth rate remains constant, when will the population reach 30,000?
__CBR-CDR__ = 1.4%
70/1.4 = 50 years
50 years = 2060

63. Population Density New York City has 8,175,113 people within 305 mi2.
Calculate the density of the population in mi2 and km2. 1 km2 = mi2
8,175,113 people = 26,804 people/ mi2
305 mi2
26,804 people x mi2 = 10,346 people
1 mi km km2

64. The population of Atlanta is 420,003 and covers an area of 131 square miles.
Calculate the density of the population in
in mi2 and km2
420,003 people = people/ mi2
131 mi2
3206 people x mi2
mi km
= 1238 people/km2

65. How many times more dense is NYC than ATL?
10,346 people/mi2 = 3.2 times 3,206 people/ mi2

66. The tiny country of Monaco has the world's highest population density
The tiny country of Monaco has the world's highest population density. With an area of 3/4 of a square mile and a total population of 32,000, Monaco has a density of almost 43,000 people per square mile.
However, since Monaco and other microstates have very high densities due to their extremely small size, Bangladesh is often considered the most densely populated country, with more than 2,200 people per square mile.

68. States by density: New Jersey, Rhode Island, Massachusetts- density States: California, Texas, New York by population Cities: New York, LA, Chicago by population

69. “People are everywhere
“People are everywhere. Some people say there are too many of us, but no one wants to leave.” The End

70. If the world had 100 people…

71. Backdrops are full sized backdrops, just scale them up or Copy-Paste to use anywhere!