Transcript Applying Population Ecology: Human Population and Urbanization Chapter 7

Applying Population Ecology:
Human Population and
Urbanization
Chapter 7
Core Case Study: Ecocity in Brazil (1)
 Curitiba – “ecological capital” of Brazil
 Inexpensive, efficient mass transit
 High-rise apartments near bus routes, mixeduse structures
 Bike and pedestrian paths
Core Case Study: Ecocity in Brazil (2)
 1.5 million trees planted
 Recycling
 Build-it-yourself system for poor
 Emphasis on ecological awareness, health,
literacy
Curitiba, Brazil
Fig. 7-1, p. 123
7-1 How Many People Can the Earth
Support?
 Concept 7-1 We do not know how long we can
continue increasing the earth’s carrying capacity
for humans without seriously degrading the lifesupport systems for us and many other species.
Human Population Explosion
 Exponential growth (J-curve) in past 200 years
 Three major reasons
• Ability to expand into diverse habitats
• Emergence of agriculture
• Sanitation systems and control of infectious
diseases
How Long Can the Human
Population Grow
 Rate slowing, but still exponential
 Uneven global growth
 No population can grow indefinitely
 2050 global estimates: 7.2–10.6 billion people
 97% growth in developing countries, least likely
to cope
Human Alteration of the Environment
Fig. 7-2, p. 125
Case Study: Are There Too Many
of Us? (1)
 Resources for growing population?
 Positive viewpoint
• Technological solutions
• Growing population a value resource
 Negative viewpoint
• 20% currently lack necessities
• Declining conditions increase death rate
• Resource use already degrade environment
Case Study: Are There Too Many
of Us? (2)
 Optimum sustainable population
 Cultural carrying capacity
UN World Population Projections
Fig. 7-3, p. 126
7-2 What Factors Influence Population
Size?
 Concept 7-2A Population size increases
because of births and immigration and
decreases through deaths and emigration.
 Concept 7-2B The average number of children
born to women in a population (total fertility rate)
is the key factor that determines the population
size.
Population Change
 Population change =
(births + immigration) - (deaths + emigration)
 Demographers look at birth rates and death
rates
Number of Children
 Fertility rates affect population size and growth
rate
 Replacement-level fertility rate
 Total fertility rate (TFR)
Most Populous Countries
1.3 billion
1.5 billion
China
1.1 billion
1.4 billion
India
USA
Indonesia
Pakistan
302 million
349 million
282 million
271 million
169 million
229 million
Brazil
189 million
229 million
Nigeria
144 million
205 million
Bangladesh
Russia
Japan
149 million
190 million
142 million
128 million
128 million
119 million
Fig. 7-4, p. 127
Case Study: The U.S. Population
Is Growing Rapidly
 Quadrupled in 100 years, despite oscillations in
TFR
 Baby boom: High TFR
 Current births outnumbering deaths and legal
immigration
 Growing faster than other developed countries
Fertility Rate of the U.S. Population
Baby boom
(1946–64)
Replacement
level
Fig. 7-5, p. 128
Changes in the U.S. Population
47 years
Life expectancy
77 years
8%
Married women working
outside the home
81%
High school
graduates
15%
83%
Homes with
flush toilets
Homes with
electricity
Living in
suburbs
Hourly manufacturing job
wage (adjusted for
inflation)
Homicides per
100,000 people
10%
98%
2%
99%
10%
52%
$3
$15
1.2
5.8
Fig. 7-6, p. 129
Factors Affecting Birth Rates (1)
 Importance of children as part of labor force
 Cost of raising and educating children
 Availability of retirement systems
 Urbanization
 Educational and employment opportunities for
women
Factors Affecting Birth Rates (2)
 Infant mortality rate
 Average marriage age
 Availability of legal abortion and reliable birth
control methods
 Religious beliefs, traditions, cultural norms
Factors Affecting Death Rates
 Population growth also response to decline in
crude death rate
 Life expectancy and infant mortality rate
important indicators of overall health
 Average life expectancy increased
 Infant mortality – barometer of a society’s
quality of life
Migration
 Migration driven by economic desires
 Other reasons
•
•
•
•
•
Religious persecution
Political oppression
Ethnic conflicts
Wars
Environmental degradation
Case Study: The United States (1)
 Nation of immigrants
 1820–1960: Most immigrants European
 Since 1960
• Latin America – 53%
• Asia – 25%
• Europe – 14%
Case Study: The United States (2)
 Opponents of immigration
• Stabilize population sooner
• Reduce growing environmental impact
• 60% of population favor reducing immigration
 Proponents of immigration
•
•
•
•
Important historical role
Do menial jobs and pay taxes
Add cultural vitality
Replace retiring baby boomers
Legal Immigration
1907
1914
New laws
restrict
immigration
Great
Depression
Fig. 7-7, p. 130
7-3 How Does a Population’s Age
Structure Affect Its Growth or Decline?
 Concept 7-3 The numbers of males and
females in young, middle, and older age groups
determine how fast populations grow or decline.
Age Structure
 Distribution of population
• Prereproductive
• Reproductive
• Postreproductive
 Country with many young people grows rapidly
 Country with many older people will decline
 Developing countries >30% under 15 years old
Population Age Structures
Male
Female
Expanding Rapidly
Guatemala
Nigeria
Saudi Arabia
Male
Female
Expanding Slowly
United States
Australia
China
Male
Female
Stable
Japan
Italy
Greece
Male
Female
Declining
Germany
Bulgaria
Russia
Fig. 7-8, p. 131
Global Connections
Fig. 7-9, p. 132
Age Structure Predicts the Future
 50% of U.S. population baby boomers
 Graying of America
 2043 – 25% of population over 65
 Changes the economy
Tracking the Baby Boomers
Fig. 7-10, p. 132
1955
1985
2015
2035
Stepped Art
Fig. 7-10, p. 132
Declines Occur in Aging Populations
 “Baby bust” or “birth dearth” – TFR below 1.5
children per couple
 Labor shortages
 Strain on governments for public services
 Fewer taxpayers
Rapid Population Decline
Fig. 7-11, p. 133
Rising Death Rate: The AIDS Tragedy
 Disrupts social, economic structure
 Removes productive young adults
 Next 50 years, 278 million will die (mostly
African)
 Eight African countries 16–39% infected adults
 Life expectancy 30–40 years
7-4 How Can We Slow Population
Growth?
 Concept 7-4 Experience indicates that the most
effective ways to slow population growth are to
invest in family planning, to reduce poverty, and
to elevate the status of women.
Stages of Demographic Transition
 Preindustrial
 Transitional – demographic trap
 Industrial
 Postindustrial
Stages of Demographic Transition
Stage 1
Preindustrial
Population
grows very
slowly
because of a
high birth
rate
(to compensate for
high infant
mortality) and
a high death
rate
Stage 2
Transitional
Population grows rapidly because birth
rates are high and death rates drop
because of improved food production
and health
Stage 3
Industrial
Population
growth slows
as both birth
and death
rates drop
because of
improved
food
production,
health, and
education
Stage 4
Postindustrial
Population growth
levels off and then
declines as birth rates
equal and then fall
below death rates
Total population
Birth rate
Death rate
Fig. 7-12, p. 134
Family Planning (1)
 Birth spacing, birth control, health care
 Increased availability of contraception
 55% drop in TFR of developing countries
 Developing countries
• Almost half pregnancies unplanned
• Lack access to family planning
Family Planning (2)
 Replacement-level fertility achievable within
decades
 Invest in family planning
 Reduce poverty
 Elevate the social and economic status of
women
Empowering Women Can Slow
Population Growth
 Educated women have fewer children
 Illiterate woman 64% of world’s population, 70%
of the poor
 When daughters considered less valuable, not
sent to school
 Poor conditions for women leads to
environmental degradation
Case Study: Slowing Population Growth
in China (1)
 Half birth date and drastically reduce TFR
 Improved quality of life
 Strict family planning
 Sons still preferred – gender imbalance
Case Study: Slowing Population Growth
in China (2)
 Population rapidly aging
 Rapidly growing economy
 Larger middle class increases resource
consumption and waste
 Sustainable economic plan needed to avoid
environmental degradation
Case Study: Slowing Population Growth
in India
 Tried to slow population growth for five decades
 Most populous country in 2015
 Problems increase with growing population
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•
•
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Poverty
Malnutrition
Environmental degradation
Growing middle class – resource consumption
7-5 What Are the Major Population and
Environmental Problems of Urban Areas?
 Concept 7-5 Cities can improve individual lives,
but most cities are unsustainable because of
high levels of resource use, waste, pollution, and
poverty.
Urban Living
 Half the world lives in urban areas
 80% of Americans in cities
 Urban areas continue to grow
• Natural increase
• Immigration
Major Trends in Urban Growth
 Proportion of urban global population growing
 Number and sizes of urban areas mushrooming
 Rapid increase in urban populations in
developing countries
 Urban growth slower in developed nations
 Poverty increasing
Urban Areas and Megacities
Fig. 7-13, p. 138
Case Study: Urbanization in the
United States
 1800–2007, increased population 5–80% in
urban areas
 Migration patterns
 Better working and housing conditions
compared to the past
 Problems in urban areas
Major Urban Centers in the United States
Fig. 7-14, p. 139
Urban Sprawl
 Gobbling up countryside
 Causes
•
•
•
•
•
Prosperity
Ample and affordable land
Automobiles
Cheap gasoline
Poor urban planning
Urban Sprawl Around Las Vegas
Fig. 7-15, p. 139
Stepped Art
Fig. 7-15, p. 139
Undesirable Impacts of Urban Sprawl
Fig. 7-16, p. 140
Consequences of Urban Sprawl
 Inadequate mass transportation
 Need to drive everywhere
 Decreased energy efficiency
 Traffic congestion
 Destruction of prime cropland, forests, wetlands
U.S. Megalopolis: Bowash
Fig. 7-17, p. 140
Advantages of Urbanization
 Economic development
 Innovation
 Education and jobs
 Technological advances
 Recycling more economically feasible
 Longer life spans
Disadvantages of Urbanization (1)
 Unsustainable systems
 Lack of vegetation
 Water problems
 Pollution and health problems
Disadvantages of Urbanization (2)
 Noise pollution
 Climate and artificial light
 Urban heat islands
 Light pollution
Urban Areas Are Rarely Sustainable
Inputs
Outputs
Energy
Solid wastes
Food
Waste heat
Water
Raw
materials
Manufactured
goods
Money
Information
Air pollutants
Water
pollutants
Greenhouse
gases
Manufactured
goods
Noise
Wealth
Ideas
Fig. 7-18, p. 141
Noise Levels
Permanent damage
begins after 8-hour
exposure
Noise Levels (in dbA)
Normal
Quiet
Rainfall
Vacuum
Lawn
Earphones Boom
Rock music
breathing
rural area
cleaner
mower
at loud level cars
Military
Normal
Chain
Air raid
Whisper
Quiet
Average
Thunderclap
rifle
conversation
saw
siren
room
factory
(nearby)
Fig. 7-19, p. 142
Urban Poor in Developing Countries
 Slums
 Shantytowns and squatter settlements
 Lack of basic services
Living in a Shantytown
Fig. 7-20, p. 143
Case Study: Mexico City (1)
 Large population
 Severe noise, water, and air pollution
 50% unemployment
 >33% live in barrios
 100,000 premature deaths per year
Case Study: Mexico City (2)
 3 million without sewer
 Fecal snow
 Geography contributes to air pollution
 Progress – tree planting and lower air pollution
7-6 How Does Transportation Affect
Urban Development?
 Concept 7-6 A combination of plentiful land,
inexpensive fuel, and an expanding network of
highways results in dispersed cities that depend
on motor vehicles for most transportation.
Cities Can Grow Outward or Upward
 Compact cities
• Transportation by walking, biking, or mass transit
• Hong Kong, Tokyo
 Dispersed cities
• Transportation by automobile
• Most American cities
Automobiles in the United States
 <10% of world’s population own 1/3 of cars
 Gas guzzlers
 40,000 people per year die from auto accidents
 Largest source of air pollution
 Lead to urban sprawl and congestion
Reduce Automobile Use
 User-pays system
 Full-cost pricing
 Tax revenues to finance mass transit, bike
paths, sidewalks
 High gasoline tax unlikely
 Need to discourage automobile use
Alternatives to Cars
 Bicycles
 Mass transit systems in urban areas
 Bus systems
 Rapid rail
Trade-offs: Bicycles
Fig. 7-21, p. 145
Trade-offs: Mass Transit Rail
Fig. 7-22, p. 145
Trade-offs: Buses
Fig. 7-23, p. 146
Trade-offs: Rapid Rail
Fig. 7-24, p. 146
7-7 How Can Cities Become More
Sustainable and Livable?
 Concept 7-7 An ecocity allows people to:
choose walking, biking, or mass transit for most
transportation needs; recycle or reuse most of
their waste; grow much of their food; and protect
biodiversity by preserving surrounding land.
Environmentally Sustainable Cities
 Smart growth
 Ecocities
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•
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•
•
Build and design people-oriented cities
Use energy and matter efficiently
Prevent pollution and reduce waste
Recycle, reuse, and compost
Protect and encourage biodiversity
Smart Growth and New Urbanism
Fig. 7-25, p. 147
Animation: Current and Projected
Population Sizes by Region
PLAY
ANIMATION
Animation: Demographic Transition Model
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ANIMATION
Animation: Resources Depletion and
Degradation
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ANIMATION
Animation: Habitat Loss and Fragmentation
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Animation: SF Bay Region Growth
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Animation: Examples of Age Structure
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Animation: U.S. Age Structure
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Animation: Economic Types
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Animation: Formation of Photochemical Smog
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Animation: Thermal Invasion and Smog
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ANIMATION
Video: Easter Island
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VIDEO
Video: Bonus for a Baby
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VIDEO
Video: Cahuachi Excavation
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Video: World AIDS Day
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