1. World Population Log http://www.census.gov/ipc/www/popclockworld.html
Date: 11/02/2010 Population:
Date: Population:

2. Bellwork Question Your parents give you two options for allowance
1,000 a month
A penny on the first day of the month that doubles to two pennies on the second day and so on until the last day of the month
How much money do you have at the end of the
month under option 2?
Which option do you choose?

4. .01
.02
.04
.08
.16
.32
.64
1.28
2.56
5.12
10.24
20.48
40.96
81.92
163.84
327.68
655.36
10,485.76
10,737,418.24
Over 10 million!!

5. Question
Which type of population exhibits this sort of growth?

6. Population & Development Botkin & Heller Chapter 4
The Human Population/
Population & Development
Botkin & Heller Chapter 4
Cartoon Guide Chapter 08
PART A

7. The Human Population and the Environment
Chapter 4
The Human Population and
the Environment

8. Basic Concepts of Population Dynamics
A group of individuals of the same species living in the same area, at the same time.
Species:
All individuals that are capable of interbreeding & producing fertile offspring.
Population dynamics
The general study of population changes.

9. Accelerated World Population Growth
First Billion: 1804
Second Billion: (123 yrs)
Third Billion: (33 yrs)
Fourth Billion: (14 yrs)
Fifth Billion: (13 yrs)
Sixth Billion: (11 yrs)

10. A Brief History of Human Population Growth
Hunters and gatherers
The world’s population was probably less than a few million
Early, pre-industrial agriculture
Allowed a much greater density of people
The first major increase in human population
Machine age
Industrial revolution led to rapid increase in human population
The Modern era
Rate of population has slowed in wealthy nations but continues to increase rapidly in poorer, less developed nations.

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13. Past and forecasted human population growth rate by geographic region and major nations
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14. Logistic growth curve. World population as total numbers and growth per decade and by development status
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15. Disparities Developed countries Low-income developing countries
15% of the world’s population
Control 80% of the world’s wealth
Low-income developing countries
37% of the world’s population
Control 3.0% of the world’s gross national income
Difference in per capita income: 63 to 1!

16. Doubling Time Changes with Changes in Growth Rate
Because the world’s population rate is increasing at a rate between 1-2% we can expect the world’s population to DOUBLE within the next 35 to 70 years.
QUESTIONS:
Look at the graph on the left. As growth rate increases what happens to doubling time?
Why is this a problem?
Do you remember the formula to calculate doubling time? If you have forgotten check page 58.
© 2008 John Wiley and Sons Publishers

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18. United States Population 1790-2000
QUESTIONS:
The growth rate in the United States is slowing. So why then is the global population continuing to rise?
What can be done about it?
United States population Growth rate of the US population appears to be slowing.
© 2008 John Wiley and Sons Publishers

19. 90% of population growth is happening in Third World

21. Age Structure Population age structure:
The proportion of the population in each age class
Affects current and future birth rates, death rates and growth rates
Has an impact on the environment
Has complications for current and future social and economic status.

22. A B C Which age structure diagram has the most young people?
Why might that be?
Which age structure diagrams have more men than women at age 80+
Which age structure diagram has the fewest elderly people? B C

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24. Population Growth Rates
(b) crude birth rate= number birth per 1000 individuals
(d) crude death rate= number death per 1000 individuals
(r) growth rate = natural increase in population expressed as
percent per years (If this number is negative,
the population is shrinking.)
equation:
r = b – d
But other factors affect population growth in a certain area…

25. Rates continued… increase population decrease population
births   deaths
immigration   emigration (exit)
r = (birth - death)+ (immigration-emigration)
immigration = migration of individuals into a population from another area or country
emigration = migration of individuals from a population bound for another country

26. Growth Rate Example r = (b - d)+ (i - e)
example: population of 10,000 has
100 births (10 per 1000)
50 deaths (5 per 1000)
10 immigration (1 per 1000)
100 emigration (10 per 1000)
You try.
B D I E
r=( 10/1000) – (5/1000) + (1/1000) – (10/1000)
r=( ) + (0.001 – 0.01)
r = – = or –0.4% per year

27. Projecting Future Population Growth
Exponential growth and doubling time
The logistic growth curve
“S” shaped curve that is generated by the logistic growth equation.
A small population grows rapidly
But the growth rate slows down
The population eventually reaches a constant size.
Logistic carrying capacity
The population size at which births equal deaths and there is no net change in population

28. Forecasting Population Change
Formula to represent population change:
P2 = P1 + (B – D) + (I – E)
P1 = number of individuals in a population at time 1
P2 = number of individuals in a population at time (time 2 = a later time)

29. The Demographic Transition
Three-stage pattern of change in birth rates and death rates.
Occurred during the process of industrial and economic development of Western nations.
Leads to a decline in population growth.
Stage I: Decline in death rate
Stage II: High growth rate
Stage III: Birth rate drops toward the death rate, leading to low or zero growth rate.

30. Population and Technology
The total impact of the human population on the environment is:
the average impact of an individual multiplied by the total number of individuals
T = P x I
T=total impact
P= population size
I=average environmental impact per person

31. The Human Population, the Quality of Life, and the Human Carrying Capacity
The number of people that can live on Earth at the same time?
To determine:
Extrapolate from past growth
The “Packing Problem” approach
Considers how many people might be packed onto Earth, not taking into sufficient account the need for lands and oceans to provide food, water, energy, construction materials, and scenic beauty and the need to maintain biological diversity

32. Human Death Rates and the Rise of Industrial Societies
Acute or epidemic disease
Appears rapidly in the population,
Affects a comparatively large percentage of it,
Declines then almost disappears, only to reappear later
Chronic disease
Is always present in a population
Typically occurs in a relatively small but relatively constant presentation of the population
Examples include heart disease, cancer, and stroke

33. Human Death Rates and the Rise of Industrial Societies
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Differences between Chronic & Acute (Epidemic) Illnesses

34. Longevity and its Effect on Population Growth
Maximum lifetime:
The genetically determined maximum possible age to which an individual of a species can live
Life expectancy:
The average number of years an individual can expect to live given the individual’s present age

35. Carrying Capacity
The environment has a CARRYING CAPACITY for each population…
Carrying capacity is the number of organisms that an environment can support.
Once a population reaches its capacity, its growth stops.

36. Question
What are some examples of things that can limit growth?

37. What can limit growth? Limiting factors limit growth
Different sizes of populations will also have different factors affecting them.
When growth has been limited its graph will look like this:

38. Growth Curves

39. Some factors fit into more than one category
Limiting Factors
Short-term factors
Those that affect a population during the year in which they become limiting
Intermediate-term factors
Those whose effects are apparent after one year but before ten years
Long-term factors
Those whose effects are not apparent for ten years
Some factors fit into more than one category

40. Density Dependent & Density Independent Factors
1. Density Dependant Factors are factors that have an increasing effect as the population increase, hence will affect larger populations.
Examples: Disease, Competition, Parasites, Predators, Food
These types of factors spread faster in larger populations.
2. Density Independent Factors effect any population, regardless of size. Population size does not matter.
Examples: Volcanic eruption, Temperature, Storms, Floods, drought, chemical pesticides

41. How Can We Achieve Zero Population Growth?
Delay the age of first childbearing by women
Birth control
Biological and Social
Breast-feeding, which can delay resumption of ovulation
Abstinence
Induction of sterility with natural agents
Contraceptive devices
National Programs to Reduce Birth Rates
Formal family planning programs to
explain the problems arising from rapid population growth
Describe the benefits to individuals of reduced population growth.

43. Thomas Malthus vs The Marquis de Condorcet
Malthus: Population will outgrow food supplies (geometric growth vs arithmetic growth)
Condorcet: Reasoned human action will reduce population, reduce waste, and maintain food supply

44. Paul Ehrlich vs Julian Simon
Ehrlich: Population is outgrowing earth’s sustainable capacity
Simon: Population growth not problem, but contributes to economic development; Need for Individual Economic Freedom

45. Population Problems Poverty Food Problems Standard of Living
Environmental Consequences of Consumption
Overcrowding

46. Population Growth: Solutions
Override
forced government programs to reduce population
Collaboration
voluntary programs and incentive based family planning programs
Economic Development
higher GNP per capita
Social Development
better education, health facilities, gender equity
Family Planning Programs
sterilization, promotion of contraceptive use