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, mixed-use structures

Bike and pedestrian paths

Fig. 7-26, p. 152WorkersInterdistrict Direct FeederExpress

City center

Bus System of Curitiba, Brazil

City center

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

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 life-support 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

Last 60 years have seen emergence of antibiotics and use of chemical pesticides (DDT) and fertilizers

Source: United Nations Population Division. World Population Prospects: The 2006 Revision Data Online.In the right hand graph, S.S.Africa stands for sub–Saharan Africa Population Database

Population growth, Regions and countries

Fig. 1-1, p. 1

Hunting andgathering

Agricultural revolution Industrialrevolution

Black Death—the Plague

World Population

?

Time

Billio

ns o

f pe

op

le

How Long Can the Human Population Grow ?

Rate slowing, but still exponential

Uneven global growth (greater in developing countries)

No population can grow indefinitely

2050 global estimates: 7.2–10.6 billion people

97% growth in developing countries, least likely to cope

World Population Projections

Fig. 7-3, p. 131

Case Study: Are There Too Many of Us? (1)

Resources for growing population?

Positive viewpoint• Technological solutions (Technological fix)

• 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 Manyof Us? (2)

Optimum sustainable population

Cultural carrying capacity

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

Fig. 7-2, p. 130

Average Crude Birth and Death Rates

Average crude birth rate Average crude death rate

Africa

LatinAmerica

Asia

Oceania

UnitedStates

NorthAmerica

Europe

3814

22

6

20

7

18

7

14

8

148

10

12

Fig. 7-2b, p. 130

Average Crude Birth and Death Rates

Fig. 7-2a, p. 130

Average crude birth rate Average crude death rate

World

All developedcountries

All developingcountries

Developingcountries

(w/o China)

21

9

11

10

24

8

27

9

Average Crude Birth and Death Rates

Number of Children

Fertility rates affect population size and growth rate

Replacement-level fertility rate

Total fertility rate (TFR)

Fig. 7-4, p. 131

US Fertility Rates (1917-2005)

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

Factors Affecting Birth Rates (1) Children as part of the labor force

http://www.gdsnet.org/classes/ChildLaborPart1.pdf

Cost of raising and educating children

http://moneycentral.msn.com/articles/family/kids/tlkidscost.asp http://www.voanews.com/english/archive/2009-08/2009-08-05-voa3.cfm?mo

ddate=2009-08-05

Availability of retirement systems

Urbanization - definition varies by country; in U.S. it revolves around 50K

Educational and employment opportunities for women

Factors Affecting Birth Rates (2)

Infant mortality rate

Average marriage age http://en.wikipedia.org/wiki/Age_at_first_marriage

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

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.

Fig. 7-8, p. 135

Population Age Structures

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

Fig. 7-8b, p. 135

Expanding RapidlyGuatamala

NigeriaSaudi Arabia

Male Female

Prereproductive ages 0-14 Reproductive ages 15-44 Postreproductive ages 45-85+

© 2004 Brooks/Cole – Thomson Learning

Population Age Structures Male Female Male Female Male Female

Expanding SlowlyUnited States

AustraliaCanada

StableSpain

AustriaGreece

DecliningGermanyBulgariaSweden

Age Structure Predicts the Future

50% of U.S. population baby boomers

Graying of America

2043 – 25% of population over 65

Changes the economy

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

Fig. 7-10, p. 136

Tracking the US Baby Boom Generation

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

Fig. 7-11, p. 137

Stage 1Preindustrial

Stage 2Transitional

Stage 3Industrial

Stage 4Postindustrial

Low Increasing Very high Decreasing Low Zero Negative

Birth rate

Total population

Death rate

Growth rate over time

Demographic Transition

Low

High

Rel

ati

ve

po

pu

lati

on

siz

e

Bir

th r

ate

an

d d

eath

rat

e(n

um

ber

per

1,0

00 p

er

yea

r)

0

10

20

30

40

50

60

70

80

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 rate and drastically reduce TFR Currently 1.79 (2009) CIA Factbook

Improved quality of life

Strict family planning (see next slide)

Sons still preferred – gender imbalance Approximately 1.1/1.0 male/female for all age groups

Family PlanningCurrently used by about 35% of country

Key Aspects of Program

Strongly encourage couples to marry later

Expand educational opportunities for men and women

Provide married couples easy access to free sterilization, contraceptives and abortion.

Provide couples who sign the pledge to have no more than 1 childsalary bonusesextra foodlarger pensionsbetter housingfree medical care and school tuition for their childpreferential treatment in employment when child grows up

Family Planning(continued)

Requiring those who break the pledge to return all benefits

Exerting pressure on women pregnant with a 3rd child to have an abortion

Requiring one of the parents in a 2-child family to be sterilized

Using mobile units and paramedics to bring sterilization, family planning, health care, and education to rural areas

Train local people to carry on the family planning program

Expect all leaders to set examples with their own family size

Current population growth rate 0.655% CIA Factbook70/0.655 = 107 years to double population at this rate

Still have high infant mortality rate 20.25 deaths / 1000 live births CIA

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

Fig. 7-12, p. 139

Percentageof world

population

Population

Population (2025)(estimated)

Illiteracy (%of adults)

Population under age 15(%)

Population growth rate (%)

Total fertility rate

Infant mortality rate

Life expectancy

GDP PPP per capita

17%20%

1.1 billion1.3 billion

1.4 billion1.63 billion

47%17%

36%22%

1.6%0.6%

2.72 children per woman (down from 5.3 in 1970)1.7 children per woman (down from 5.7 in 1972)

30.15

20.25

67 years male/72 females

71 years males/ 75 females

$2,880 $4,980

Demographic Data on India and China

8147

Percent living below $2 per day

Case Study: Slowing Population Growth in India

Tried to slow population growth for five decades

High illiteracy rate of about 71%, 80-90% are rural women

Initially provided information about advantages of small families

1976 government started mass sterilization program, mainly for those with 2 or more children; supposedly voluntary with financial incentives to volunteers; coercion used in rural areas

1978 government raised the legal minimum are for marriage from 18 to 21 for men and from 15 to 18 for women

No change in population growth rate between 1971-1981

Current population growth rate 1.548 (2009)

70/1.548 = doubling time of 45 years

Most populous country in 2015

Problems increase with growing population

PovertyMalnutritionEnvironmental degradationGrowing 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.

ArgentinaPopulated centers with 2,000 or more

Canada Places of 1,000 or more*

China

Cities designated by the State Council and other places with density of 1,500 or more per sq. km.*

India

Specified towns with governments and places with 5,000 or more and at least three-fourths of the male labor force not in agriculture*

JapanCities (shi) with 50,000 or more*

Maldives Male, the capitalMexico Localities of 2,500 or more

New ZealandCities, towns, etc. with 1,000 or more

NigerCapital city and department and district capitals

Norway Localities of 200 or more

PeruPopulated centers with 100 or more dwellings

SenegalAgglomerations of 10,000 or more

United StatesPlaces of 2,500 or more, urbanized areas of 50,000 or more*

Country Urban Definition

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

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

Urban Sprawl

Gobbling up countryside

Causes• Prosperity

• Ample and affordable land

• Automobiles

• Cheap gasoline

• Poor urban planning

Consequences of Urban Sprawl

Inadequate mass transportation

Need to drive everywhere

Decreased energy efficiency

Traffic congestion

Destruction of prime cropland, forests, wetlands

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

© 2006 Brooks/Cole - Thomson

Fig. 7-19, p. 146

Noise Levels (in dbA)

Permanent damagebegins after 8-hour

exposure

0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150

85

Normalbreathing

Whisper

Quietrural area

Quietroom

Rainfall

Normalconversation

Vacuumcleaner

Averagefactory

Lawnmower

Chainsaw

Rock music

Thunderclap(nearby)

Earphonesat loud level

Air raidsiren

Boomcars

Militaryrifle

Urban Poor in Developing Countries

Slums

Shantytowns and squatter settlements

Lack of basic services

Millions

Source: United Nations, World Urbanization Prospects: The 2003 Revision (medium scenario), 2004.

1950 2000 2015

Largest Cities, Worldwide

811 12

17 18

34

2123

36

London Tokyo New York

Sao Paulo

MexicoCity

Tokyo Delhi Mumbai(Bombay)

Tokyo

© 2006 Population Reference Bureau

• The largest cities in the world are growing rapidly, and they are shifting from the more developed regions to the less developed regions. In 1950 the three largest cities were in more developed countries; by 2000, only Tokyo remained in the top three. • In 1950, New York was the largest city in the world, with a population of about 12 million. By 2015, the largest city worldwide is projected to be Tokyo, with triple this population size: 36 million.

s on Largest Cities, Worldwide

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

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• Build and design people-oriented cities

• Use energy and matter efficiently

• Prevent pollution and reduce waste

• Recycle, reuse, and compost

• Protect and encourage biodiversity