Environmental Science: Toward a Sustainable Future Richard T. Wright

1
Environmental Science Toward a
Sustainable Future Richard T. Wright
Chapter 5

• The Human Population Dimensions

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Chapter 5 Human Population Growth and the
Consequences

• Chapter Topics
• 5.1 Human population expansion and its cause
• 5.2 Different worlds
• 5.3 Consequences of population growth and
  affluence
• 5.4 Dynamics of population growth

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5.1 Human Population Expansion and Its Cause

• Reasons for the patterns of growth
• Biotic potential exceeds environmental
  resistance birth rates exceed death rates
• There are 6.3 billion people on Earth
• World Population on Feb 24, 2008 6,652,714,868
• If each one stood up, pronounced their name, and
  sat down
• It would take 600 years to complete roll call
• By 2025 it will take 1,000 years to complete this
  exercise

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5.1 Human Population Expansion and Its Cause
World Population over the Centuries
9,000 human beings added to the planet every hour
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5.1 Human Population Expansion and Its Cause
Reasons for the Human Population Explosion

• Causes of disease recognized
• Bacteria, viruses, parasites
• Treatment of sewage drinking water
• Improvements in nutrition
• Discovery of antibiotics
• Improvements in medicine
• vaccines
• Increase in number of women who actually reach
  child-bearing age
• Short doubling times in some countries

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5.1 Human Population Expansion and Its Cause
Changing Human Survivorship Curves Went from B
to A
A
Survival
B
Age
Birth
Death
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5.1 Human Population Expansion and Its Cause
World Population Growth and Absolute Growth
Total fertility rate in 1960s was an average of
5.0 children per woman. It has since declined to
its present value of 2.8 children per woman.
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5.1 Human Population Expansion and Its Cause
Population Projections Based on Different
Fertility Assumptions

• U.N. Population Divisions projection
• If fertility rates continue to decrease, (low on
  graph) the global human population may reach 8.9
  billion by 2050
• But will continue to in crease, leveling off
  around 10 billion in the 22nd century
• If fertility rates remain unchanged, (constant on
  graph) the population may be 12.8 billion in 2050

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5.1 Human Population Expansion and Its Cause
Average number of children, grandchildren, and
Great Grandchildren in

• America 14
• West Germany 5
• Africa 258

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5.2 Different Worlds

• Section Topics
• Rich nations, poor nations
• Population growth in rich and poor nations
• Different populations, different problems

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5.2 Different Worlds Human Poverty Index for
Developing Countries
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5.2 Different Worlds Economic Categories Based
on Per Capita Gross National Income (see Fig. 5-4)

• High-income, highly developed, industrialized
  countries (designated by the World Bank)
• 964 Million People
• United States, Japan, Canada, Australia, New
  Zealand, Western Europe, Scandinavia, Singapore,
  Taiwan, Israel
• Average GNI per capita 26,710

New York City
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5.2 Different Worlds Economic Categories Based
on Per Capita Gross National Income (see Fig. 5-4)

• Middle-income, moderately developed countries
  (designated by the World Bank)
• 2.7 Billion People
• Latin America (Mexico, Central America, South
  America), Northern and Southern Africa, China
• Average GNI per capita 1,850

Panama City, Panama
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5.2 Different Worlds Economic Categories Based
on Per Capita Gross National Income (see Fig. 5-4)

• Low-income, developing countries
• 2.65 Billion People
• Eastern, Western and Central Africa, India,
  Central Asia
• Average GNI per capita 430

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5.2 Different Worlds Disparities

• Developed countries
• 16 of the worlds population
• Control 81 of the worlds wealth
• Low-income developing countries
• 41 of the worlds population
• Control 3.4 of the worlds gross national income
• Difference in per capita income 62 to 1!

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5.2 Different Worlds Disparities

• United Nations Development Program has devised
  the Human Poverty Index (HPI) based on
• Life Expectancy
• Literacy
• Living Standards (living on 1 per day or less)
• Developed countries
• 10 and 15 of the people are poor (unable to
  afford adequate food, shelter, or clothing)
• Low-income developing countries
• 45 are poor (unable to afford adequate food,
  shelter, or clothing)

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5.2 Different Worlds Population Increase in
Developed and Developing Countries
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5.2 Different Worlds Population Data for
Selected Countries (Table 5-3)
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5.2 Different Worlds Different Populations,
Different Problems

• Human pressure on the environment caused by three
  factors
• Population size
• Affluence
• Technology
• I P x A x T
• The US with only 5 of the worlds population is
  responsible for over 24 of total global
  emissions of CO2, global deforestation and loss
  of biodiversity

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5.2 Different Worlds Different Populations,
Different Problems

• Suitable attention to wildlife conservation,
  pollution control, energy conservation, and
  recycling may offset the negative impact of
  consumer lifestyle
• The IPAT formula might be modified to
• I P x A x T
• S
• S Stewardship

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5.2 Different Worlds Ecological Footprints by
World Region

• The average American places at least 20 times the
  demand on Earths resources as does an average
  person in Bangladesh

Fig. 5.7 here
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5.2 Different Worlds Global Conditions for a
Sustainable Population

• Lower fertility rates (stabilize population)
• Consumption must decrease
• Protect the environment (stewardly action must
  increase)

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5.3 Consequences of Population Growth Affluence

• Section Topics
• The Developing Countries
• Affluence

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5.3 Consequences of Population Growth Affluence
Developing or Developed Nations?

• Match the characteristics below with (a)
  developed or (b) developing countries
• 1. High fertility rates
• 2. High consumptive lifestyles use 80 of
  worlds
• wealth
• 3. Intense poverty
• 4. Eat high on the food chain
• 5. Long doubling times
• 6. High environmental degradation
• 7. 16-20 of the worlds population

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5.3 Consequences of Population Growth Affluence
Developing or Developed Nations?

• Match the characteristics below with (a)
  developed or (b) developing countries
• 1. High fertility rates (b)
• 2. High consumptive lifestyles use 80 of
  worlds
• wealth (a)
• 3. Intense poverty (b)
• 4. Eat high on the food chain (a)
• 5. Long doubling times (a)
• 6. High environmental degradation (b)
• 7. 16-20 of the worlds population (a)

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5.3 Consequences of Population Growth Affluence
Basic Human Needs

• Many developing countries around the world are
  not able to offer the following basic human
  needs
• Drinkable Water
• Edible Food
• Safe Housing
• Health Care
• An Education
• A Job

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5.3 Consequences of Population Growth Affluence
The Developing Countries

• Impacts of rapid growth on an agricultural
  population
• Reform the system of land ownership
• Intensify cultivation of existing land to
  increase production per unit area
• Open new land to farm
• Move to cities and seek employment
• Engage in illicit activities for income
• Move to other countries

How do these solutions aggravate the problems?
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5.3 Consequences of Population Growth Affluence
Growing Cities
Growth of the top 10 metropolitan areas from 1975
to 2015.
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5.3 Consequences of Population Growth Affluence
Consequences of Exploding Populations in the
Developing World
There are numerous connections between unchecked
population growth and environmental problems.
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5.3 Consequences of Population Growth Affluence
Consequences of Exploding Populations
deforestation resource depletion loss of
agricultural land biodiversity disease pest
resistance population migration irrigation wetland
s
Does Increased Population Cause
MORE
LESS
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5.3 Consequences of Population Growth Affluence
Affluence in the United States

• As citizens of the US, we
• Consume the largest share of major commodities.
• Eat more than three times the global average in
  meat.
• Lead the world in paper consumption.
• Improves our environment with increasing
  affluence.
• Clean up our immediate environment by
  transferring waste to more distant locations.
• Isolate ourselves or are unaware of the
  environmental stresses caused by our consumptive
  lifestyles.

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5.4 Dynamics of Population Growth

• Section Topics
• Population profiles
• Future populations
• Population momentum
• The demographic transition

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5.4 Dynamics of Population Growth Population
Profiles of the United States

• Population Profiles
• Show the proportion of males/females at each age
  for a given population
• Numbers are obtained from census taken every 10
  years
• Adjusted using data regarding births, deaths,
  immigration, aging of population

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5.4 Dynamics of Population Growth Population
Profiles of the United States

• Population Profiles of US
• Boom or Bust?
• Proportion of people who die before 60 is small
• Population below age 60 is an echo of past
  events that affected birthrates.
• Ex. ages 55-59 in 1990 are reflection of Great
  Depression
• Ex. ages 30-44 in 1990 were born in 1946 after WW
  II
• Used to project need for schools, job market,
  retirement homes

1990
2000
2050
Note increasing elderly population.
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5.4 Dynamics of Population Growth Population
Profiles of the United States

• Fertility Rates in US
• Changes in fertility led to the baby boom
  (following WW II) and baby bust (following the
  60s-70s recession) .
• Current fertility rate is at replacement level.

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5.4 Dynamics of Population Growth Projecting
Future Populations Developed Countries

• Most Developed Countries
• Graying of the Population
• Large numbers of persons are moving into older
  age groups.
• Number of children is diminishing.
• Who will produce the goods and services needed by
  the aging population?
• To maintain current populations, most of these
  countries will have to triple their current
  immigration levels in the near future.

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5.4 Dynamics of Population GrowthPopulation
Profiles of the United States

• US Population Projections
• No Graying Here!
• In contrast to other developed countries, the
  fertility rate in the US reversed direction in
  the 1980s and started back up.
• With higher fertility rate of 2.0, the US
  population is projected to be 420 million by 2050
  and to increase growing indefinitely.
• Immigration is assumed to remain constant at
  current levels ? 880,000 per year.

Note increasing elderly population.
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5.4 Dynamics of Population Growth Future United
States Populations

• US Population Projections
• No Graying Here!
• Projections shift drastically with changes in
  fertility.
• Contrast the 1988 projection, based on fertility
  rate of 1.8, with the 2000 projection, based on
  an increased fertility rate of 2.1 .

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5.4 Dynamics of Population Growth Population
Projections Developing Nations

• Population Profile of Iraq (Developing Nations)
• Population Momentum
• Countries with a pyramid-shaped population
  profile will continue to grow for 50-60 years,
  even after the total fertility rate is reduced
• Occurs because such a small portion of the
  population is in the upper age groups
• Many children are entering their reproductive
  years

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5.4 Dynamics of Population Growth Comparing
Projected Populations
Fertility Rate lt 2
Fertility Rate gt 2
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5.4 Dynamics of Population Growth The
Demographic Transition

• Demographic Transition
• Casual link between modernization and a decline
  in birth/death rates
• Decline in fertility
• Economic development
• Modern population stability
• Low infant mortality balanced by low birth rates

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5.4 Dynamics of Population Growth The
Demographic Transition

• Demographic Transition
• Phase I- Primitive Stability
• High crude birth rate offset by equally high
  crude death rate
• Phase II- Epidemiologic Transition
• Declining crude death rate
• High fertility and crude birth rate
• Growth phase

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5.4 Dynamics of Population Growth The
Demographic Transition

• Demographic Transition
• Phase III- Fertility Transition
• Declining fertility rate
• Declining crude birth rate
• Still population growth
• Phase IV- Modern Stability
• Low crude death rate
• Low crude birth rate
• Decrease in growth

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5.4 Dynamics of Population Growth Calculating
Fertility Rates and Doubling Times
(CBR CDR)/10 Rate of increase or decrease in
population per 1,000 per year
70/Rate of Increase Doubling Time
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5.4 Dynamics of Population Growth Calculating
Fertility Rates and Doubling Times Practice
(CBR CDR)/10 Rate of Increase
or Decrease
70/Rate of Increase Doubling Time
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5.4 Dynamics of Population Growth Demographic
Transition Comparisons

• Demographic Transition to a Stable
  Population
• CBRs and CDRs are shown for major regions of the
  world
• Dividing line separates countries at or well
  along in transition from those still in the
  middle of transition

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5.4 Dynamics of Population Growth By the Year
2000

• 65 out of 117 countries will not be able to feed
  their own people
• One billion people will be living in cities that
  cannot support its inhabitants
• 400 million more women will be in need of child
  spacing services
• 600 million new jobs need to be created for new
  entrants into the workforce
• We will need 2x as much fresh water
• 300 million additional children will need
  teachers/books/classrooms

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The Earth is in our Hands
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End of Chapter 5