-
C o r e C a s e s t u d y
22 Cities and Sustainability
The Ecocity Concept in Curitiba, Brazil
Urban planners envision large portions of the growing human
population living in more environmentally sustainable cities,
called ecocities or green cities. This is not just a futuristic
dream. One such ecocity is Curitiba (“koor-i-TEE-ba”), a city of
3.2 mil-lion people known as the “ecological capital of
Brazil.”
In 1969, planners in this city decided to focus on creating an
efficient mass transit system rather than on accomodating a growing
number of cars. Curitiba now has the world’s best bus system, in
which clean and modern buses transport about 72% of all commuters
every day throughout the city using express lanes dedicated to
buses (Figure 22-1). Only high-rise apartment
buildings are allowed near major bus routes, and each building
must devote its bottom two floors to stores—a practice that reduces
the need for residents to travel.
Cars are banned from 49 blocks in the center of the down-town
area, which has a network of pedestrian walkways con-nected to bus
stations, parks, and bicycle paths running through-out most of the
city. Consequently, Curitiba uses less energy per person and has
lower emissions of greenhouse gases and other air pollutants, as
well as less traffic congestion than do most comparable cities.
The city transformed flood-prone areas along its six rivers into
a series of interconnected parks. Volunteers have planted more than
1.5 million trees throughout the city, none of which can be cut
down without a permit, which also requires that two trees must be
planted for each one that is cut down.
Curitiba recycles roughly 70% of its paper and 60% of its metal,
glass, and plastic, which is collected from households three times
a week. Recovered materials are sold mostly to the city’s more than
500 major industries, which must meet strict pollution standards.
Most of these businesses are located in an industrial park outside
the city limits. A major bus line runs to the park, but many of the
workers live nearby and can walk or bike to work.
The poor receive free medical and dental care, child care, and
job training, and 40 feeding centers are available for street
chil-dren. Poor people can exchange filled garbage bags for surplus
food, bus tokens, and school supplies. Also, the city has a
build-it-yourself program that gives a poor family a plot of land,
building materials, two trees, and an hour’s consultation with an
architect.
This internationally acclaimed model of urban planning and
sustainability is the brainchild of architect and former college
professor Jaime Lerner, who has served as the city’s mayor three
times since 1969. When its transformation began, Curitiba was no
more well off than any other Brazilian city. In 1980, its per
capita GDP was only 10% above the average for Brazil. By 1996, it
was 65% above average. Its economy did well partly because
companies were attracted to the city’s pleasant environment, lack
of congestion, and ease of commuting.
Curitiba now faces new challenges, as do all cities, mostly
because of increasing population pressure. Throughout this
chap-ter, we will examine these challenges and some possible
solutions for Curitiba and other urban areas.
Figure 22-1 solutions: This bus rapid transit (BRT) system in
Curitiba, Brazil, moves large numbers of passengers around rapidly
because each of the system’s five major “spokes,” connecting the
city center with outlying districts, has two express lanes used
only by buses. Double- and triple-length bus sections are coupled
together as needed to carry up to 300 passengers. Boarding is
speeded up by the use of extra-wide bus doors and boarding
platforms under glass tubes where passengers can pay before getting
on the bus (top left).
Citycenter
InterdistrictExpress Feeder
Route
Direct Workers
John
Mai
er, J
r./Pe
ter A
rnol
d, In
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-
587Links: refers to the Core
refers to the book’s GOODNEWS
refers to good news about the Case Study. sustainability theme.
environmental challenges we face.
Key Questions and Concepts
22-1 What are the major population trends in urban areas?ConCept
22 - 1 Urbanization continues to increase steadily and the numbers
and sizes of urban areas are growing rapidly, especially in
less-developed countries.
22-2 What are the major urban resource and environmental
problems?ConCept 22 -2 Most cities are unsustainable because of
high levels of resource use, waste, pollution, and poverty.
22-3 How does transportation affect urban environmental
impacts?ConCept 22 -3 In some countries, many people live in
dispersed urban areas and depend mostly on motor vehicles for their
transportation, which greatly expands their ecological
footprints.
22-4 How important is urban land-use planning? ConCept 22 -4
Urban land-use planning can help to reduce uncontrolled sprawl and
slow the resulting degradation of air, water, land, biodiversity,
and other natural resources.
22-5 How can cities become more sustainable and livable?ConCept
22 -5 An ecocity allows people to choose walking, biking, or mass
transit for most transportation needs; to recycle or reuse most of
their wastes; to grow much of their food; and to protect
biodiversity by preserving surrounding land.
Note: Supplements 2 (p. S3), 3 (p. S6), 8 (p. S30), and 9 (p.
S57) can be used with this chapter.
The city is not an ecological monstrosity. It is rather the
place where both the problems and the opportunities of modern
technological civilization are most potent and visible.
PETEr SElf
22-1 What Are the Major Population Trends in Urban Areas?
ConCept 22-1 urbanization continues to increase steadily and the
numbers and sizes of urban areas are growing rapidly, especially in
less-developed countries.
Half of the World’s People Live in Urban AreasPeople live in
urban areas, or cities (Figure 22-2, top, p. 588), suburbs that
spread out around city centers (Figure 22-2, middle), and rural
areas or villages (Fig- ure 22-2, bottom). Urbanization is the
creation and growth of urban and suburban areas. It is measured as
the percentage of the people in a country or in the world living in
such areas. Urban growth is the rate of increase of urban
populations.
The world’s first cities emerged about 6,000 years ago. The
first city to reach a population of 1 million was Rome, Italy, in
133 bc. Since then, the world has become increasingly urbanized.
Today, half of the world’s peo-ple, and 79% of Americans, live in
urban areas.
Urban areas grow in two ways—by natural increase (more births
than deaths) and by immigration, mostly from rural areas. Rural
people are pulled to urban areas
in search of jobs, food, housing, educational opportu-nities,
better health care, and entertainment. Some are also pushed from
rural to urban areas by factors such as poverty, lack of land for
growing food, declining agricul-tural jobs, famine, war, and
religious, racial, and politi-cal conflicts.
People are also pushed or pulled to cities by gov-ernment
policies that favor urban over rural areas. For example,
less-developed countries tend to spend most of their budgets on
economic development and job creation in urban areas. Some
governments establish lower food prices in urban areas, which
reward city dwellers, help to keep leaders in power, and attract
the rural poor.
Four major trends in urban population dynamics have emerged, and
they are important for understand-ing the problems and challenges
of urban growth. First, the proportion of the global population
living in urban areas is increasing. In 1900, the average
population of the
▲
-
588 ChaPTEr 22 Cities and Sustainability
world’s biggest 100 cities was about 700,000. By 2009, that
average had climbed to 6 million.
Between 1850 and 2009, the percentage of people living in urban
areas increased from 2% to 50%, and it could reach 66% by 2030.
About 88% of this growth will occur in already overcrowded and
economically stressed cities in less-developed countries, where
four of every ten people live in urban areas (Figure 22-3). In each
of the two largest of these countries, China and India, more than
25 million people move to cities each year.
Second, the numbers and sizes of urban areas are mush-rooming.
Every week, more than 1 million people are added to the world’s
urban areas. Between 2008 and 2015, the number of urban areas with
a million or more people is projected to increase from 400 to 564.
Demographers project that by 2025, China will add 60 new cities,
each hosting 1.5 million to 5 million peo-ple. By comparison, the
United States currently has just 9 cities of more than 1 million
people. Between 2010 and 2030, China will add more city dwellers
than the entire current population of the United States.
Currently, there are 18 megacities or megalopolises—cities with
10 million or more people—up from 8 in 1985. Fifteen of them are in
less-developed countries (Figure 22-4). Such megacities will soon
be eclipsed by hypercities each having more than 20 million people.
Tokyo, Japan, is the leading city in this category, hav-ing 32
million people—more than the entire population of Canada. But
according to UN projections, by 2015, Tokyo, Japan, Mumbai
(formerly Bombay) and Delhi in India, Dhaka, Bangladesh, and São
Paulo, Brazil, will be the top five most populated cities. All of
them, along with Lagos, Nigeria, are projected to become
hypercities by then.
Figure 22-2 About half of the world’s people live in urban
areas, or cities, such as Shanghai, China (top), and their
surrounding suburban areas such as this one in Southern California
(middle). The other half live in rural areas—in villages such as
this one in the southern African country of Malawi (bottom), in
small towns, or in the countryside.
Oliy
/Shu
tters
tock
iofo
to/S
hutte
rsto
ckM
agda
lene
Buj
ak/S
hutte
rsto
ck
Figure 22-3 This graph tracks urban population growth for the
world, as well as for less-developed countries and more-developed
countries, 1950–2010, with projections to 2030. Question: Why do
you think the growth in urban populations is much higher in
less-developed countries than in more-developed countries? (Data
from United Nations Population Division)
Urb
an p
opul
atio
n(b
illio
ns)
1950 1960 1970 1980 1990 2000 2010 2020
Less-developedcountries
World
More-developedcountries
Year
20300
1
2
3
4
5
-
Third, urban growth is much slower in more-developed countries
than in less-developed countries (Figure 22-3). However,
more-developed countries, now with 75% urbanization, are projected
to reach 81% urbanization by 2030.
Fourth, poverty is becoming increasingly urbanized, mostly in
less-developed countries. The United Nations esti-mates that at
least 1 billion people in less-developed countries (more than three
times the current U.S. popu-lation) live in crowded and unsanitary
slums and shan-tytowns within most cities or on their outskirts;
within 30 years this number may double.
thinking about urban trends
If you could reverse one of the four urban trends discussed
here, which one would it be? Which of these trends has Curitiba,
Brazil, (Core Case study) reversed?
If you visit a poor, over-crowded area of a large city in a
less-developed country, your senses may be over-whelmed by a
vibrant but chaotic crush of people, vehi-cles of all types,
traffic jams (Figure 22-5), noise, and odors, including smoke from
burning trash, as well as from wood and coal cooking fires, and raw
sewage. Many people sleep on the streets or live in crowded,
unsanitary, rickety, and unsafe slums and shantytowns with
little or no access to safe drinking water or modern sanitation
facilities.
Figure 22-4 Global outlook: Major urban areas throughout the
world are revealed in these satellite images of the earth at night,
showing city lights. Currently, the 50% of the world’s people who
live in urban areas occupy about 2% of the earth’s land area. Note
that most of the urban areas are found along the continental
coasts, which explains why most of Africa and much of the interior
of South America, Asia, and Australia are dark at night. This
figure also shows the populations of the world’s 18 megacities
(each with 10 million or more people) in 2010. All but three are
located in less-developed countries. Question: In order, what were
the world’s five most populous cities in 2010? (Data from National
Geophysics Data Center, National Oceanic and Atmospheric
Administration, and United Nations)
Los Angeles15.2 million
Cairo14.5 million
Beijing22 million
Tokyo32 million
Shanghai17 million
Mexico City20.5 million
New York19.7 million
London12.9 million
São Paulo18.9 million
Rio de Janeiro12 million
Buenos Aires13.1 million
Karachi11.8 million
Dhaka13 million
Mumbai(Bombay)19.2 million
Osaka17.4 million
Jakarta18.9 million
Hong Kong15.8 million
Manila16.3 million
Seoul20.6 million
Kolkata(Calcutta)15.1 million
Lagos13.4 million
Delhi18.6 millionMoscow
15 million
Bangkok12 million
Figure 22-5 This is a typical daily traffic jam of people,
carts, bicycle taxis, and other vehicles in an older section of
Delhi, India—a city with 13 million people.
Mar
k Ed
war
ds/P
eter
Arn
old,
Inc.
ConCEPT 22-1 589
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590 ChaPTEr 22 Cities and Sustainability
■ Case study
Urbanization in the United States Between 1800 and 2008, the
percentage of the U.S. population living in urban areas increased
from 5% to 79%. This population shift has occurred in four
phases.
First, people migrated from rural areas to large central cities.
Currently, three-fourths of Americans live in cities with at least
50,000 people, and nearly half live in urban areas with 1 million
or more residents (Figure 22-6).
Second, many people migrated from large central cities to
smaller cities and suburbs. Currently, about half of urban
Americans live in the suburbs (Figure 22-2, middle), nearly a third
in central cities, and the rest in rural housing developments
beyond suburbs.
Third, many people migrated from the North and East to the South
and West. Since 1980, about 80% of the U.S. population increase has
occurred in the South and West. Between 2009 and 2043, demographers
project that the fastest growing U.S. states will continue to be
Nevada, Arizona, and Florida, although increased drought and heat
waves due to projected climate change may alter
this trend. According to a 2006 study by the Center for
Environment and Population, the South and West also contain many of
the country’s ecological hot spots (see Figure 27 on p. S55 in
Supplement 8) where biodiver-sity is threatened.
Fourth, since the 1970s, and especially since 1990, some people
have fled both cities and suburbs, and migrated to developed areas
outside of suburbs. The result is rapid growth of exurbs—housing
developments scattered over vast areas that lie beyond suburbs and
have no socio-economic centers.
Since 1920, many of the worst urban envi-ronmental problems in
the United States have been reduced significantly (Figure 6-7, p.
132). Most people have better working and housing conditions, and
air and water quality have improved. Better sanita-tion, clean
public water supplies, and medical care have slashed death rates
and incidences of sickness from infectious diseases. Concentrating
most of the popula-tion in urban areas also has helped to protect
the coun-try’s biodiversity by reducing the destruction and
degra-dation of wildlife habitat.
GOODNEWS
Figure 22-6 The major urban areas in the United States are
revealed in satellite images of the earth at night show-ing city
lights (top). About eight of every ten Americans live in urban
areas, which occupy a small but growing fraction of the country’s
land area. The cities identified in the image are the
fastest-growing metropolitan areas. Nearly half (48%) of all
Americans live in cities of 1 million or more people, most of which
are projected to merge into huge urban areas shown as shaded
sections in the bottom map. Question: Why are many of the largest
urban areas located near water? (Data from National Geophysical
Data Center/National Oceanic and Atmospheric Admin-istration, U.S.
Census Bureau)
Seattle
Portland
Boise
San FranciscoFresno
Las Vegas
PhoenixDallas
HoustonAustin
Laredo
McAllenNaples
Miami
Orlando
Atlanta
KansasCity
Salt LakeCity Provo Denver
Minneapolis
Chicago
CincinnatiSt. Louis
Tulsa
Memphis
Nashville
Charlotte
Myrtle BeachWilmington
Raleigh
Washington, D.C.
New York
Boston
TucsonSan Diego
LosAngeles
-
However, a number of U.S. cities—especially older ones—have
deteriorating services and aging infrastruc-tures (streets,
bridges, dams, power lines, schools, waste management, water supply
pipes, and sewers). Indeed, according to a 2009 study by the
American Society of Civil Engineers (ASCE), the United States has
fallen $2.2 trillion behind in maintaining its vital public
infrastruc-ture of roads, bridges, sewer systems, dams, and
schools. This amounts to more than $7,000 for each U.S.
citizen.
The ASCE president warned that “crumbling infra-structure has a
direct impact on personal and economic health.” For example, the
ASCE report found that aging sewer systems allow huge volumes of
untreated waste-water to flow into U.S. waterways every year. This
results in pollution of many urban streams and beaches, as well as
the potential for contaminating groundwater and surface water.
At a time when there are urgent needs to upgrade rapidly
deteriorating infrastructure, many U.S. cities face budget crises
and the resulting cuts to public services, as businesses and people
move to the suburbs and exurbs, and city revenues from property
taxes decline. The eco-nomic recession beginning in 2008 has
worsened this situation, as city and state budgets have suffered
from declining tax revenues. In hard times, funds for main-taining
infrastructure are usually the first to be cut.
Urban Sprawl Gobbles Up the CountrysideIn the United States and
some other countries, urban sprawl—the growth of low-density
development on the edges of cities and towns—is eliminating
surround-ing agricultural and wild lands (Figure 22-7). It results
in a far-flung hodgepodge of housing developments, (Figure 22-2,
middle) shopping malls, parking lots, and office complexes that are
loosely connected by multi-lane highways and freeways.
Five major factors promoted urban sprawl in the United States.
First, ample land was available for most cities to spread outward.
Second, low-cost gasoline combined with federal and state funding
of highways encouraged automobile use and the development of
outlying tracts of land. Third, starting around 1950, fed-eral
government home loan guarantees for World War II veterans
stimulated the development of suburbs; since then, tax laws have
encouraged home owner-ship. Fourth, most state and local zoning
laws favored large residential lots and the separation of
residential and commercial areas. Fifth, most urban areas consist
of multiple local governments, which rarely work together to
develop an overall plan for managing urban growth. Similar
processes have occurred in other countries.
Figure 22-7 These satellite images show the growth of urban
sprawl in and around the U.S. city of Las Vegas, Nevada, between
1973 and 2003—a process that continues. Between 1970 and 2009, the
population of water-short Clark County, which includes Las Vegas,
more than quadrupled from 463,000 to around 1.9 million, making it
one of the nation’s fastest-growing urban areas. Question: What
might be a limiting factor on population growth in Las Vegas?
Imag
e co
urte
sy o
f the
U.S
. Geo
logi
cal S
urve
y
1973
Imag
e co
urte
sy o
f the
U.S
. Geo
logi
cal S
urve
y
2003
ConCEPT 22-1 591
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592 ChaPTEr 22 Cities and Sustainability
As they grow outward, separate urban areas some-times merge to
form a megalopolis. For example, the remaining open spaces between
the U.S. cities of Bos-ton, Massachusetts, New York, New York, and
Washing-ton, DC, are rapidly urbanizing (Figure 22-6, bottom). The
result is an almost 800-kilometer-long (500-mile-long) urban area
that contains about 35 million people and is often called Bowash.
Other such megalopolises include the areas between Amsterdam, the
Netherlands, and Paris, France, in Europe; Japan’s
Tokyo–Yoko-hama–Osaka–Kobe corridor known as Tokohama (with nearly
50 million people); and the Brazilian industrial triangle made up
of São Paulo, Rio de Janeiro, and Belo Horizonte.
In a nutshell, urban sprawl is the product of afford-able land,
automobiles, cheap gasoline, and little or no urban planning. Many
people prefer living in suburbs and exurbs. Compared to central
cities, these areas pro-vide lower-density living and access to
larger lot sizes and single-family homes. Often these areas also
have newer public schools and lower crime rates.
However, urban sprawl has caused or contributed to a number of
environmental problems. Because of non-existent or inadequate mass
transportation in most such areas, sprawl forces people to drive
everywhere, and in the process, their vehicles consume significant
amounts of gasoline while emitting greenhouse gases and other forms
of air pollution. Sprawl has decreased energy effi-ciency,
increased traffic congestion, and destroyed prime cropland,
forests, and wetlands.
Urban sprawl also has led to the economic deaths of many central
cities, as people and businesses move out of these areas. In
addition, a similar but new problem has arisen since 2000—the
growing decay of suburban shopping centers. As cheap credit has
dried up, making
consumers less willing to use their credit cards, and as online
shopping has replaced many car trips, numer-ous suburban shopping
centers have closed. Some of these abandoned shopping centers are
being recycled as apartment or office buildings and churches.
Others will remain as crumbling eyesores or urban dinosaurs
sur-rounded by vast empty parking lots on the outskirts of many
cities.
Analysts at the Metropolitan Institute at Virginia Tech have
suggested that this problem is deeper than an economic slump. They
suggest that the suburban population of U.S. consumers is shrinking
as the baby boomers (the large number of Americans born in the two
decades after World War II) grow older. As a result, fewer suburban
households have growing children, and many older Americans now
prefer to live in more cul-turally diverse and interesting
redeveloped central cit-ies. These analysts project that the year
2025 will see a surplus of 22 million large-lot homes in U.S.
suburbs and exurbs.
Figure 22-8 summarizes these and other undesirable consequences
of urban sprawl.
thinking about urban sprawl
Do you think the advantages of sprawl outweigh its
disadvan-tages? What might happen to suburban and exurban areas as
the prices of oil and gasoline rise sharply? How might this affect
your lifestyle?
Examine how the San Francisco Bay area in the U.S. state of
California grew in population between 1900 and 1990 at
CengageNow.
Urban Sprawl
Natural Capital Degradation
Loss of cropland
Loss and fragmentation of forests, grasslands, wetlands, and
wildlife habitat
Land andBiodiversity
Increased use and pollution of surface water and groundwater
Increased runoff and flooding
Water
Increased energy use and waste
Increased emissions of carbon dioxide and other air
pollutants
Energy, Air,and Climate
Decline of downtown business districts
More unemployment in central cities
Economic Effects
Figure 22-8 These are some of the undesirable impacts of urban
sprawl or car-dependent devel-opment. Question: Which five of these
effects do you think are the most harmful?
-
ConCEPT 22-2 593
22-2 What Are the Major Urban Resource and Environmental
Problems?
ConCept 22-2 Most cities are unsustainable because of high
levels of resource use, waste, pollution, and poverty.
▲
Urbanization Has AdvantagesUrbanization has many benefits. From
an economic standpoint, cities are centers of economic
develop-ment, innovation, education, technological advances, and
jobs. They serve as centers of industry, commerce, and
transportation.
Urban residents in many parts of the world tend to live longer
than do rural residents and to have lower infant mortality and
fertility rates. They also have bet-ter access to medical care,
family planning, education, and social services than do their rural
counterparts. However, the health benefits of urban living are
usually greater for the rich than for the poor.
Urban areas also have some environmental advan-tages. Recycling
is more economically feasible because concentrations of recyclable
materials and funding for recycling programs tend to be higher in
urban areas. Concentrating people in cities helps to preserve
biodi-versity by reducing the stress on wildlife habitats. Cen-tral
cities also can save energy if residents rely more on
energy-efficient mass transportation, walking, and bicy-cling, as
they do in Curitiba, Brazil (Core Case study).
Urbanization Has Disadvantages Half of the world’s 6.9 billion
people live in urban areas and each year, about 63 million
people—an average of nearly 7,200 per hour—are added to these
areas. Such intense population pressure and high population
densi-ties (see Figure 6-1, p. 125) makes most of the world’s
cities more environmentally unsustainable every year (Concept
22-2).
Even in more sustainable cities such as Curitiba, Brazil, (Core
Case study) this pressure is taking its toll. The city’s once clear
streams are often overloaded with pollutants. The bus system is
nearing capacity, and car ownership is on the rise. While the
recycling rate is still among the highest in the world, the
region’s only landfill is now full. Architect Jorge Wilheim, who
helped create Curitiba’s master plan, points out that the city’s
population is now more than five times as large as it was in 1965
when the plan was drafted. With the metropolitan area’s population
at 3.2 million, Wilheim believes it is time to adjust the plan.
We will touch on aspects of a possible new vision for Curitiba
and similar solutions for other cities through-
out this chapter. Here we take a closer look at some
sig-nificant problems faced by cities.
Cities Have Huge Ecological Footprints. Accord-ing to the
Worldwatch Institute, although urban popu-lations occupy only about
2% of the earth’s land area, they consume about 75% of its
resources and pro-duce about 75% of the world’s climate-changing
CO2 emissions from human activities. Because of this high resource
input of food, water, and materials, and the resulting high waste
output (Figure 22-9, p. 594), most of the world’s cities have huge
ecological footprints and are not self-sustaining systems (Concept
22-2).
While urbanization does help to preserve some of the earth’s
biodiversity, large areas of land must be dis-turbed and degraded
to provide urban dwellers with food, water, energy, minerals, and
other resources. This decreases and degrades biodiversity,
overall.
Thus, urban areas have huge ecological footprints that extend
far beyond their boundaries. If you live in a city, you can
calculate its ecological footprint by going to the website
www.redefiningprogress.org/. (Also, see the Guest Essay on this
topic by Michael Cain at CengageNOW.)
ConneCtionsurban Living and biodiversity awareness
Recent studies reveal that most urban dwellers live most or all
of their lives in an artificial environment that isolates them from
forests, grasslands, streams, and other natural areas that make up
the world’s biodiversity. As a result, many urban residents tend to
be uninformed about the importance of protecting not only the
earth’s increasingly threatened biodi-versity but also its other
forms of natural capital that support their lives and the cities in
which they live.
Most Cities Lack Vegetation. In urban areas, most trees, shrubs,
grasses, and other plants are destroyed to make way for buildings,
roads, parking lots, and hous-ing developments. Thus, most cities
do not benefit from vegetation that would absorb air pollutants,
give off oxy-gen, provide shade, reduce soil erosion, provide
wildlife habitats, and offer aesthetic pleasure. As one observer
remarked, “Cities are places where they cut down most of the trees
and then name the streets after them.”
Cities Often Have Water Problems. As cities grow and their water
demands increase, expensive reservoirs
GOODNEWS
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594 ChaPTEr 22 Cities and Sustainability
and canals must be built and deeper wells must be drilled. This
can deprive rural and wild areas of surface water and can deplete
underground water supplies.
Flooding also tends to be greater in some cities that are built
on floodplains near rivers or along low-lying coastlines subject to
natural flooding. In addition, cov-ering land with buildings,
asphalt, and concrete causes precipitation to run off quickly and
overload storm drains. Further, urban development has often
destroyed or degraded large areas of wetlands that have served as
natural sponges to help absorb excess storm water. Many of the
world’s largest coastal cities (Figure 22-4) face a new threat of
flooding some time in this century if sea levels rise as projected
due to climate disruption (see Chapter 19, pp. 507–508).
For cities in arid areas that depend on water with-drawn from
rivers and reservoirs that are fed by moun-taintop glaciers,
projected climate change will likely cre-ate another problem. Those
cities will face severe water shortages as atmospheric warming
melts these moun-taintop glaciers.
For example, in some especially arid areas in the western United
States (see Figure 13-5, p. 322) fed by the Colorado River (see
Figure 13-1, p. 317) and Cal-ifornia’s water distribution system
(see Figure 13-16, p. 331), irrigated agriculture may no longer be
possible. For urban populations in some of these areas, this will
lead to sharply rising food prices, because food will have to be
shipped in from other areas. These urban dwellers will also face
more water shortages, especially in areas where groundwater is
being depleted (see Figure 13-9, p. 326).
The good news is that we have a variety of methods for reducing
both groundwater deple-tion (see Figure 13-12, p. 327) and urban
water use and waste (see Figure 13-23, p. 339).
Cities Concentrate Pollution and Health Problems. Because of
their high population densities and high resource consumption,
cities produce most of the world’s air pollution, water pollution,
and solid and hazardous wastes. Pollutant levels are generally
higher because
Inputs
Energy
Outputs
Food
Water
Raw materials
Manufactured goods
Money
Information
Solid wastes
Waste heat
Air pollutants
Water pollutants
Greenhouse gases
Manufactured goods
Noise
Wealth
Ideas
London
Figure 22-9 natural capi-tal degradation: Urban areas are rarely
sustainable systems. The typical city depends on large nonurban
areas for huge inputs of mat-ter and energy resources, while it
generates large outputs of waste matter and heat. According to an
analy-sis by Mathis Wackernagel and William Rees, developers of the
ecological footprint concept, London, England, requires an area 58
times as large as the city to supply its residents with resources
(see area outlined in red on map below). They estimate that if all
of the world’s people used resources at the same rate as Londoners
do, it would take at least three more planet Earths to meet their
needs. Question: How would you apply the three principles of
sustainability (see back cover) to lessen some of these
impacts?
GOODNEWS
-
ConCEPT 22-2 595
pollution is produced in a smaller area and cannot be dispersed
and diluted as readily as pollution produced in rural areas
can.
The concentration of transportation vehicles and industrial
facilities in urban centers results in just over two-thirds of the
world’s emissions of CO2 from human-related sources. This causes
disruption of local and regional portions of the carbon cycle (see
Fig- ure 3-19, p. 70). High concentrations of urban air pol-lution
also disrupt the nitrogen cycle (see Figure 3-20, p. 71) because of
large quantities of nitrogen oxide emissions, which play a key role
in the formation of photochemical smog. Also, nitric acid and
nitrate emis-sions are major components of acid deposition in urban
areas and beyond (see Figure 18-14, p. 477, and Fig- ure 18-15, p.
478). Nitrogen nutrients in urban runoff and in discharges from
urban sewage treatment plants can also disrupt the nitrogen cycle
in nearby lakes and other bodies of water, and cause excessive
eutrophica-tion (see Figure 20-11, p, 537).
In addition, high population densities in urban areas can
increase the spread of infectious diseases, especially if adequate
drinking water and sewage systems are not available.
Cities Have Excessive Noise. Most urban dwellers are subjected
to noise pollution: any unwanted, disturb-ing, or harmful sound
that damages, impairs, or inter-feres with hearing, causes stress,
hampers concentration and work efficiency, or causes accidents.
Noise levels are measured in decibel-A (dbA) sound pressure units
that vary with different human activities (Figure 22-10).
Sound pressure becomes damaging at about 85 dbA and painful at
around 120 dbA. At 180 dbA, sound can kill. Prolonged exposure to
sound levels above 85 dbA can cause permanent hearing damage. Just
one-and-a-half minutes of exposure to 110 decibels or more can
cause such damage. About one of every eight children and teens in
the United States has some per-
manent hearing loss, mostly from listening to music at loud
levels.
Cities Affect Local Climates and Cause Light Pollution. On
average, cities tend to be warmer, rainier, foggier, and cloudier
than suburbs and nearby rural areas. In cities, the enormous amount
of heat generated by cars, factories, furnaces, lights, air
conditioners, and heat-absorbing dark roofs and streets creates an
urban heat island that is surrounded by cooler suburban and rural
areas. As cities grow and merge (Figure 22-6), their heat islands
merge, which can reduce the natural dilution and cleansing of
polluted air.
In areas with hot climates, the urban heat island effect puts
heat stress on humans and many other organisms. It can also greatly
increase dependence on air conditioning for cooling, and it can
increase the formation of photochemical smog (see Figures 18-11 and
18-12, p. 475) by speeding up the chemical reac-tions involved in
its formation. This in turn increases energy consumption,
greenhouse gas emissions, and other forms of air pollution in a
vicious circle, or posi-tive feedback loop.
The artificial light created by cities (Figures 22-2, top and
22-4) is a form of light pollution that affects some plant and
animal species. For example, some endan-gered sea turtles lay their
eggs on beaches at night and require darkness to do so. In
addition, each year large numbers of migrating birds, lured off
course by the lights of high-rise buildings, fatally collide with
these structures. Light pollution also makes it difficult for
astronomers and urban dwellers to study and enjoy the night
sky.
thinking about disadvantages of urbanization
Which two of the disadvantages discussed here for living in
urban areas do you think are the most serious? Explain.
Figure 22-10 This chart lists noise levels of some common sounds
(in decibel-A [dbA] sound pressure units). You are being exposed to
a sound level high enough to cause permanent hearing damage if a
noise requires you to raise your voice to be heard, if a noise
causes your ears to ring, or if a noise makes nearby speech seem
muffled. Prolonged exposure to lower noise levels and occasional
loud sounds may not damage your hearing, but such expo-sure can
greatly increase internal stress. Question: How many times per day
are your ears subjected to noise levels of 85 dbA or more?
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
Normalbreathing
Whisper
Quietrural area
Quietroom
Rainfall
Normalconversation
Vacuumcleaner
Averagefactory
Lawnmower
Chainsaw
Rock music
Thunderclap(nearby)
Boomcars
Earphonesat loud level
Air raidsiren
Rifle
85
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596 ChaPTEr 22 Cities and Sustainability
✓
Life Is a Desperate Struggle for the Urban Poor in
Less-Developed Countries Poverty is a way of life for many urban
dwellers in less-developed countries. At least 1 billion people
live under crowded and unsanitary conditions in cities in these
countries (Figure 22-11), and according to a 2006 UN study, that
number could reach 1.4 billion by 2020. In sub-Saharan Africa, more
than seven of every ten urban residents live in such conditions,
according to the UN.
Some of these people live in slums—areas dominated by
dilapidated tenements and rooming houses where numerous people
might live in a single room (see Fig- ure 6-19, p. 141). Asia’s
largest slum, Dharavi, in Mum-bai (Bombay), India, is home to
600,000 people and has one public toilet for every 800
residents.
Other poor people live in squatter settlements and shantytowns
on the outskirts of cities. They build shacks from corrugated
metal, plastic sheets, scrap wood, card-board, and other scavenged
building materials, or they
live in rusted shipping containers and junked cars. Some
shantytowns are illegal subdivisions where landowners rent land to
the poor without city approval. Others are illegal squatter
settlements where people take over unoc-cupied land without the
owners’ permission, simply because it is their only option for
survival.
Poor people living in shantytowns and squatter settlements or on
the streets (Figure 6-21, p. 143) usu-ally lack clean water
supplies, sewers, electricity, and roads, and are exposed to severe
air and water pollu-tion as well as hazardous wastes from nearby
factories. Many of these settlements are in locations especially
prone to landslides, flooding, or earthquakes. Some city
governments regularly bulldoze squatter shacks and send police to
drive illegal settlers out. The people usu-ally move back in within
a few days or weeks, or build another shantytown elsewhere.
Governments can address these problems. For example, they can
slow the migration from rural to urban areas by improving
education, health care, and family planning in the countryside, and
by encourag-ing investment in small towns. Governments can also
designate land for squatter settlements and supply them with clean
water and sanitation, as Curitiba, Brazil, has done (Core Case
study). Guaranteeing regular bus service enables workers living in
such set-tlements to travel to and from their workplaces.
In Brazil and Peru, governments legally recognize existing slums
(favelas) and grant legal titles to the land. They base this on
evidence that poor people usually improve their living conditions
once they know they have a permanent place to live. They can then
become productive working citizens who contribute to tax rev-enues
that, in turn, pay for the government programs that assist the
poor. In some cases, impoverished people with titles to land have
developed their own schools, day care centers, and other such
structures for social improvement. Unfortunately, in many of the
poor-est countries, extensive government corruption diverts some of
the limited funds available to help the poor into the hands of
those who need it least.
how wouLd you Vote?
Should squatters living in or near cities in less-developed
countries be given title to the land they live on? Cast your vote
online at www.cengage.com/login.
■ Case study
Mexico City Mexico City—the world’s second most populous city—is
an urban area in crisis. Its 20.5 million residents repre-sent a
number roughly equal to the entire population of Australia or the
U.S. state of New York. Each year, at least 400,000 new residents
arrive.
Mexico City suffers from severe air pollution, close to 50%
unemployment, deafening noise, overcrowding,
Figure 22-11 Global outlook: Extreme poverty forces hundreds of
millions of people to live in slums and shantytowns, such as this
one in Rio de Janeiro, Brazil, with no access to adequate water
supplies, sewage disposal, and other vital services.
Unite
d N
atio
ns
-
ConCEPT 22-2 597
traffic congestion, inadequate public transportation, and a
soaring crime rate. More than one-third of its resi-dents live in
slums called barrios or in squatter settle-ments that lack running
water and electricity.
At least 3 million people in the barrios have no sew-age
facilities. As a result, huge amounts of human waste are deposited
in gutters, vacant lots, and open ditches every day, attracting
armies of rats and swarms of flies. When the winds pick up dried
excrement, a fecal snow blankets parts of the city. This
bacteria-laden fallout leads to widespread salmonella and hepatitis
infections, especially among children.
Mexico City has one of the world’s worst air pollu-tion problems
(Figure 22-12) because of a combination of factors: too many cars,
polluting factories, a warm, sunny climate and thus more smog, and
topographical bad luck. The city sits in a high-elevation,
bowl-shaped valley surrounded on three sides by
mountains—condi-tions that trap air pollutants at ground level.
Breathing its air is said to be roughly equivalent to smoking three
packs of cigarettes per day, and respiratory diseases are rampant.
(See The Habitable Planet, Video 11 at
www.learner.org/resources/series209.html to learn how scientists
are measuring air pollution levels in Mexico City.)
The city’s air and water pollution cause an estimated 100,000
premature deaths per year. Writer Carlos Fuen-tes has nicknamed it
“Makesicko City.”
Large-scale water withdrawals from the city’s aqui-fer have
caused parts of the city to subside by 9 meters
(30 feet) during the last century. Some areas are now subsiding
as much as 30 centimeters (1 foot) a year. Mexico City’s growing
population increasingly relies on water pumped in from as far away
as 150 kilome-ters (93 miles). Large amounts of energy are used to
pump this water overland and then uphill 1,000 meters (3,300 feet)
to the city.
Progress has been made in solving some of Mexico City’s
problems. The percentage of days each year in which air pollution
standards are violated has fallen from 50% to 20%. The city
government has banned cars in its central zone and requires air
pollution controls on all cars made after 1991. It has also phased
out use of leaded gasoline and called for old buses, taxis, and
delivery trucks to be replaced with vehicles that produce fewer
emissions. The city also bought land for use as green space and
planted more than 25 million trees to help absorb pollutants. In
2009, the city formed a Waste Commission. It is working to build
state-of-the-art waste processing centers that, within a few years,
will process as much as 85% of the city’s solid waste through
recycling and composting, as well as by burn-ing some of it for
energy.
thinking about Mexico City and Curitiba
What are two sustainability strategies used in Curi-tiba,
Brazil, (Core Case study) that might be helpful in Mexico City?
Figure 22-12 Photochemical smog in Mexico City, Mexico, is
caused by cars and factories that generate pollutants and by the
city’s location within a bowl-shaped valley that traps emissions,
causing them to accumulate to danger-ous levels.
Mar
k Ed
war
ds/P
eter
Arn
old,
Inc.
GOODNEWS
-
598 ChaPTEr 22 Cities and Sustainability
22-3 How Does Transportation Affect Urban Environmental
Impacts?
ConCept 22-3 in some countries, many people live in widely
dispersed urban areas and depend mostly on motor vehicles for their
transportation, which greatly expands their ecological
footprints.
▲
Cities Can Grow Outward or Upward If a city cannot spread
outward, it must grow verti-cally—upward and downward (below
ground)—so that it occupies a small land area with a high
population density. Most people living in compact cities such as
Hong Kong, China, and Tokyo, Japan, get around by walking, biking,
or using mass transit such as rail or buses. Some high-rise
apartment buildings in these Asian cities con-tain everything from
grocery stores to fitness centers so their residents do not need to
travel for food, entertain-ment, and other services.
In other parts of the world, a combination of plen-tiful land,
relatively cheap gasoline, and networks of highways have produced
dispersed cities whose residents depend on motor vehicles for most
travel (Concept 22-3). Such car-centered cities are found in the
United States, Canada, Australia, and other countries where ample
land often is available for these cities to expand out-ward. The
resulting urban sprawl (Figure 22-7) can have a number of
undesirable effects (Figure 22-8).
The United States is a prime example of a car-cen-tered nation.
With 4.6% of the world’s people, the United States has almost
one-third of the world’s pas-senger cars and commercial vehicles.
In its dispersed urban areas, passenger vehicles are used for 98%
of all transportation, and three of every four residents drive
alone to work every day. Largely because of urban sprawl, all
Americans combined drive about the same distance each year as the
total distance driven by all other drivers in the world, and in the
process use about 43% of the world’s gasoline.
Motor Vehicles Have Advantages and Disadvantages Motor vehicles
provide mobility and offer a convenient and comfortable way to get
from one place to another. For many people, they are also symbols
of power, sex appeal, social status, and success. Much of the
world’s economy is also built on producing motor vehicles and
supplying fuel, roads, services, and repairs for them.
Despite their important benefits, motor vehicles have many
harmful effects on people and on the envi-ronment. Globally,
automobile accidents kill approxi-mately 1.2 million people a
year—an average of 3,300
deaths per day—and injure another 15 million people. They also
kill about 50 million wild animals and family pets every year.
In the United States, motor vehicle accidents kill more than
40,000 people per year and injure another 5 million, at least
300,000 of them severely. Car accidents have killed more Americans
than have all the wars in the country’s history.
Motor vehicles are the world’s largest source of out-door air
pollution, which causes 30,000–60,000 prema-ture deaths per year in
the United States, according to the Environmental Protection
Agency. They are also the fastest-growing source of
climate-changing CO2 emis-sions. In addition, they account for
two-thirds of the oil used (mostly in the form of gasoline) in the
United States and one-third of the world’s oil consumption.
Motor vehicles have helped create urban sprawl and the car
commuter culture. At least a third of the world’s urban land and
half of that in the United States is devoted to roads, parking
lots, gasoline stations, and other automobile-related uses. This
prompted urban expert Lewis Mumford to suggest that the U.S.
national flower should be the concrete cloverleaf (Fig-ure
22-13).
Another problem is congestion. If current trends continue, U.S.
motorists will spend an average of 2 years of their lives in
traffic jams, as streets and freeways often resemble parking lots.
According to a 2008 report by the American Society of Civil
Engineers, about 45% of all major urban U.S. highways are regularly
congested. Traffic congestion in some cities in less-developed
coun-tries is much worse. Building more roads may not be the
answer. Many analysts agree with economist Rob-ert Samuelson that
“the number of cars expands to fill available concrete.”
Reducing Automobile Use Is Not Easy, but It Can Be Done Some
environmental scientists and economists suggest that we can reduce
the harmful effects of automobile use by making drivers pay
directly for most of the envi-ronmental and health costs caused by
their automobile use—a user-pays approach, based on honest
environ-mental accounting.
One way to phase in such full-cost pricing would be to charge a
tax or fee on gasoline to cover the estimated
-
harmful costs of driving. According to a study by the
International Center for Technology Assessment, such a tax would
amount to about $3.18 per liter ($12 per gallon) of gasoline in the
United States (see Chapter 16, p. 402). Gradually phasing in such a
tax, as has been done in many European nations, would spur the use
of more energy-efficient motor vehicles and mass transit, decrease
dependence on imported oil, and thus increase economic and national
security. It would also reduce pollution and environmental
degradation and help to slow projected climate change.
researCh Frontier
Determining the full costs of using gasoline and how to include
such costs in its market price; see www.cengage .com/login.
Proponents of this approach urge governments to do two major
things. First, fund programs to educate peo-ple about the hidden
costs they are paying for gasoline. Second, use gasoline tax
revenues to help finance mass transit systems, bike lanes, and
sidewalks as alternatives to cars, and reduce taxes on income,
wages, and wealth to offset the increased taxes on gasoline. Such a
tax shift would help to make higher gasoline taxes more
politi-cally and economically acceptable.
Europe, Japan, Singapore, and China have all devel-oped rapid
mass transit systems within and between urban areas, as well as
networks of sidewalks and bike lanes in many urban and suburban
areas. Analysts warn that countries such as the United States that
lag behind in developing such systems will face great
difficulties
in dealing with the projected decline in oil production and with
rapidly rising oil and gasoline prices. The end result could be a
sharp decline for suburban housing and shopping centers as they
become environmentally and economically unsustainable. As noted
earlier in this chapter, there is some evidence that this is
beginning to happen already in some U.S. suburban areas.
Taxing gasoline heavily would be difficult in the United States,
for three reasons. First, it faces strong opposition from two
groups. One group is made up of those people who feel they are
already overtaxed, many of whom are largely unaware of the huge
hidden costs they are paying for gasoline. The other group is made
up of the powerful transportation-related industries such as
carmakers, oil and tire companies, road builders, and many real
estate developers.
Second, the dispersed nature of most U.S. urban areas makes
people dependent on cars. Third, fast, efficient, reliable, and
affordable mass transit options, bike lanes, and sidewalks are not
widely available in the United States. These factors make it
politically difficult to raise gasoline taxes. But U.S. taxpayers
might accept sharp increases in gasoline taxes if a tax shift were
employed, as mentioned above.
Another way to reduce automobile use and urban congestion is to
raise parking fees and charge tolls on roads, tunnels, and bridges
leading into cities—espe-cially during peak traffic times. Densely
populated Sin-gapore is rarely congested because it auctions the
rights to buy a car, and its cars carry electronic sensors that
automatically charge the drivers a fee every time they enter the
city. Several European cities have also imposed stiff fees for
motor vehicles entering their central cities.
Figure 22-13 Concrete cloverleafs like this tangled network of
thruways in the U.S. city of Los Angeles, California, are found in
most of the world’s increasingly car-dependent cities.
iofo
to/S
hutte
rsto
ck
ConCEPT 22-3 599
-
600 ChaPTEr 22 Cities and Sustainability
Examples include London, England, Stockholm, Swe-den, and Milan,
Italy.
Paris, France, which has some of Europe’s worst traf-fic
congestion, has upgraded its mass transit system and created
express lanes for buses and bicycles on main thoroughfares, while
reducing the lanes available for cars. The city also established a
program that provides almost 21,000 bikes for rent at 1,450 rental
stations throughout the city at a cost of just over $1 a day.
Sadly, within two years 80% of the bikes had been stolen or
vandalized and had to be replaced at great cost. Portland, Oregon,
also had to abandon its bike-sharing program because of theft and
vandalism. However, the U.S. city of Boston, Massachusetts, plans
to start such a program.
In Germany, Austria, Italy, Switzerland, and the Netherlands,
more than 300 cities have car-sharing networks (see the Case Study
that follows). Members reserve a car in advance or call the network
and are directed to the closest car. They are billed monthly for
the time they use a car and the distance they travel. In Berlin,
Germany, car sharing has cut car ownership by 75%. According to the
Worldwatch Institute, car sharing in Europe has reduced the average
driver’s CO2 emis-sions by 40–50%. Car-share companies have
sprouted up in the United States in cities such as Madison,
Wis-consin, Portland, Oregon, New York, New York, and Los Angeles,
California, among others.
■ Case study
Zipcars In 1999, Robin Chase and Antje Danielson, two
entre-preneurs living in Cambridge, Massachusetts (USA) recognized
a need among city dwellers who were tired of paying high rates for
parking, insurance, and other costs of owning a car. In cities with
extensive mass tran-sit systems such as New York, New York, and
Boston, Massachusetts, a car amounts to a significant expense
because of these high costs and because the mass transit option
would allow almost anyone to get along without a car much of the
time. So why pay the high costs for a car that you may only use
occasionally?
To Chase and Danielson, the answer was: don’t pay those costs;
instead, join a car-sharing network and pay a much lower price for
the convenience of having a car when you need it, renting it by the
hour. The two women formed Zipcar, a network whose membership has
doubled almost every year since 1999. In 2009, its 325,000 members
in the United States were sharing 6,500 cars (10–15% of them hybrid
cars).
To become a Zipster, as the members call themselves, you pay a
small application charge and an annual $50 fee. In cities where
they are available, members can rent a Zipcar for $6 to $10 per
hour, which includes the costs of gas, insurance, and maintenance.
They make reservations online and are told where to go to pick up
the car. A membership card unlocks the vehicle. When finished with
the car, the member returns it to where it
was picked it up, and charges for the use of the vehicle are
applied to the member’s credit card.
Traveling cleaning crews (many of them college stu-dents) clean
the cars once each week. Members agree to keep the cars clean and
not to smoke or allow dogs to damage the cars. The system seems to
work, as Zipcars are always booked.
Now, several businesses, including Google, ask their employees
to use Zipcars for daily business trips in and around the cities
where they work. The company’s president estimates that car sharing
costs the company about a third of the cost of keeping company cars
and reimbursing employees for using their own cars.
thinking aboutCar sharing
If you are or someday might be a car owner living in a city
where car-sharing is available, would you consider selling your car
and joining a car-sharing network? Explain.
Some Cities Promote Alternatives to Cars Mayors and urban
planners in many parts of the world are beginning to rethink the
role of the car in urban transportation systems and are providing a
mix of other options, as they have in Curitiba, Brazil (Core Case
study). Leaders in less-developed countries are recognizing that
most of their people could never afford to own automobiles, and
they are questioning the development of expensive car-oriented
systems that mostly benefit the affluent minority of their
citizens.
There are several alternatives to motor vehicles, each with its
own advantages and disadvantages. One widely used alternative is
the bicycle (Figure 22-14). Bicycles reduce congestion, promote
physical fitness, emit no CO2 or other air pollutants, cost little
to buy and operate, and reduce the need for parking space. Each
year, the number of bicycles produced globally is about 2.5 times
the number of cars produced. There is also a growing use of
electric bicycles.
Bicycling and walking account for about a third of all urban
trips in the Netherlands and in Copenhagen, Denmark. By contrast,
bicycles account for only about 1% of urban trips in the United
States. But one of five Americans say they would bicycle to work if
safe bike lanes were available and if their employers provided
secure bike storage and showers at work. There is a growing
complete streets movement in the United States that is devoted to
making city streets as useful and safe for bicyclists and
pedestrians as they are for cars and trucks.
thinking about bicycles
Do you, or would you, use a conventional or an electric bicycle
to go to and from work or school? Explain.
-
Heavy-rail systems (subways, elevated railways, and metro
trains) and light-rail systems (streetcars, trolley cars, and
tramways) have their advantages and disad-vantages (Figure 22-15).
At one time, all major U.S. cities had effective light-rail
systems, but they were dis-mantled to promote car and bus use (see
Case Study, p. S10, in Supplement 3). However, such systems are
being built again in several U.S. cities. An outstanding
example is the light-rail system in Minneapolis, Minne-sota,
which opened in 2005 and surprised planners by drawing 50% more
riders than they had expected.
The rail system in Hong Kong, China, is one of the world’s most
successful, primarily because the city is densely populated and
thus half its population can walk to a subway station within 5
minutes. Owning a car is also extremely expensive in this crowded
city, which helps to make the rail system attractive to almost
everyone.
Buses are the most widely used form of mass transit within urban
areas worldwide, mainly because they have more advantages than
disadvantages (Figure 22-16). Curitiba, Brazil, has one of the
world’s best bus rapid transit systems, which carries tens of
thousands of pas-sengers a day (Core Case study, Figure 22-1). But
the system is now feeling the strain of pop-ulation pressures, and
car use is increasing in Curitiba. Transportation officials there
are considering building a light-rail system to help carry the
rapidly growing pas-senger load.
Similar bus rapid transit systems have been devel-oped in
Bogotá, Colombia, and are being planned for cities such as Mexico
City, Mexico; Jakarta, Indonesia; Seoul, South Korea; Beijing and
20 other cities in China; Ottawa and Toronto in Canada; and the
U.S. cities of Los Angeles, California; Minneapolis, Minnesota; and
Las Vegas, Nevada.
A rapid-rail system between urban areas is another option for
reducing the use of cars. In western Europe and Japan, high-speed
bullet trains travel between cit-ies at up to 306 kilometers (190
miles) per hour. Such trains began operating in Japan in 1964 and
now carry almost a million passengers a day. Since 1964, there has
not been a single casualty, and late arrivals average only 6
seconds, explaining why some analysts consider this system to be
one of the new wonders of the world.
Figure 22-14 Bicycle use has advantages and disadvantages. The
key to increasing bicycle use is the creation of bicycle-friendly
sys-tems, including bike lanes. Some cities actually provide
bicycles that people can rent at a very low cost. In addition,
Japan and the Netherlands strive to integrate the use of bicycles
and commuter rail by providing secure bicycle parking at rail
stations. Question: Which single advantage and which single
disadvantage do you think are the most important?
Provide little protection in an accident
Provide no protection from bad weather
Are impractical for long trips
Secure bike parking not yet widespread
Are quiet and non-polluting
Take few resources to make
Burn no fossil fuels
Require little parking space
Advantages Disadvantages
Bicycles
Trade-Offs
Figure 22-15 Mass transit rail systems in urban areas have
advan-tages and disadvantages. Question: Which single advantage and
which single disadvantage do you think are the most important?
Expensive to build and maintain
Cost-effective only along a densely populated corridor
Commits riders to transportation schedules
Advantages Disadvantages
Uses less energy and produces less air pollution than cars
do
Use less land than roads and parking lots use
Causes fewer injuries and deaths than cars
Mass Transit Rail
Trade-Offs
Can lose money because they require affordable fares
Can get caught in traffic and add to noise and pollution
Commit riders to transportation schedules
Reduce car use and air pollution
Can be rerouted as needed
Cheaper than heavy-rail system
Advantages Disadvantages
Buses
Trade-Offs
Figure 22-16 Bus rapid transit systems (where several buses
run-ning in express lanes can be coupled together) and conventional
bus systems in urban areas have advantages and disadvantages.
Question: Which single advantage and which single disadvantage do
you think are the most important?
ConCEPT 22-3 601
-
602 ChaPTEr 22 Cities and Sustainability
✓
Figure 22-17 lists the major advantages and disad-vantages of
such rapid-rail systems.
In the United States, nearly half of all households have no
reasonable access to bus or train service, accord-ing to the
American Society of Civil Engineers. But a high-speed bullet train
network could replace airplanes, buses, and private cars for most
medium-distance travel between major American cities (Figure
22-18). Some planners call for placing high-speed train tracks
along interstate freeways, as the federal government already owns
the roads and adjacent rights-of-way. These estab-lished
transportation corridors could also be used for a new electric grid
system, which could provide a more fuel-efficient means to run the
trains.
Six Middle Eastern nations—Saudi Arabia, Bahrain, Kuwait, Oman,
Qatar, and the United Arab Emirates—plan to spend more than $100
billion to build a modern railway network that will link them
together. China has the world’s fastest bullet train, and by 2010,
will have completed a vast network of 42 high-speed train routes
throughout the country, which is roughly the same size as the
United States. One major goal of China’s leaders is to make the
country more economically competitive by providing fast and
energy-efficient transportation among its major cities.
In the United States, planners have been talking about building
high-speed trains for decades, but plans have been slow to
materialize. As of 2014, there will likely be only one such train
running on a line between Tampa and Orlando, Florida. However, in
2010, the U.S. government began planning for 12 other high-speed
rail corridors in various locations around the country. Part of the
reason for the delay in building rapid-rail systems in the United
States is that revenues from gasoline taxes have been used mostly
to build highways at the expense of mass transit.
ConneCtionswind Farms and high-speed trains
Ever ride on a wind train? Americans could get that oppor-tunity
if the visions of some planners become reality. A few railroad
companies are exploring the idea of powering cross-country trains
with electricity from wind farms, most of which are already located
in the right places for such a plan. Wind trains would be highly
efficient with little or no emis-sions of greenhouse gases or other
air pollutants.
how wouLd you Vote?
Should the United States (or the country where you live) develop
rapid-rail systems to connect some of its urban areas, even though
this will be quite costly? Cast your vote online at
www.cengage.com/login.
Figure 22-17 Rapid-rail systems between urban areas have
advan-tages and disadvantages. Western Europe and Japan have
high-speed bullet trains that travel between cities at up to 306
kilometers (190 miles) per hour. Question: Which single advantage
and which single disadvantage do you think are the most
important?
Costly to run and maintain
Causes noise and vibration for nearby residents
Adds some risk of collision at car crossings
Much more energy efficient per rider than cars and planes
are
Less air pollution than cars and planes
Can reduce need for air travel, cars, roads, and parking
areas
Advantages Disadvantages
Rapid Rail
Trade-Offs
Figure 22-18 solutions: Some potential routes for high-speed
bullet trains in the United States and parts of Canada are shown
here. Such a system would allow rapid, comfortable, safe, and
affordable travel between major cities in a region. It would
greatly reduce dependence on cars, buses, and airplanes for trips
between these urban areas and would also decrease greenhouse gas
emissions and other forms of air pollution. Question: Why do you
think such a system has not been developed in the United States?
(Data from High Speed Rail Association, U.S. Depart-ment of
Transportation, Amtrak)
-
22-4 How Important Is Urban Land-Use Planning?
ConCept 22-4 urban land-use planning can help to reduce
uncontrolled sprawl and slow the resulting degradation of air,
water, land, biodiversity, and other natural resources.
▲
Conventional Land-Use Planning Most urban and some rural areas
use various forms of landuse planning to determine the best present
and future use of each parcel of land.
Land-use planning has often encouraged future population growth
and economic development, regard-less of its environmental and
social consequences. This typically has led to uncontrolled or
poorly controlled urban growth and sprawl.
A major reason for this often-destructive process in the United
States and in some other countries is heavy reliance on property
taxes levied on all buildings and land parcels based on their
economic value. In the United States, 90% of the revenue used by
local governments to provide public services, such as schools,
police and fire protection, and water and sewer systems, comes from
property taxes. As a result, local governments often raise money by
promoting urban growth, because they usually cannot raise property
tax rates enough on existing properties to meet expanding
needs.
Once a land-use plan is developed, governments control the uses
of various parcels of land by legal and economic methods. The most
widely used approach is zoning, in which various parcels of land
are desig-nated for certain uses such as residential, commercial,
or mixed use. However, zoning can be used to control growth and
protect areas from certain types of devel-opment. For example,
cities such as Portland, Ore-gon (USA), and Curitiba, Brazil, (Core
Case study) have used zoning to encourage high-density development
along major mass transit corridors and to reduce automobile use and
air pollution.
Despite its usefulness, zoning has several draw-backs. One
problem is that some developers can influ-ence or modify zoning
decisions in ways that threaten or destroy wetlands, prime
cropland, forested areas, and open space. Another problem is that
zoning often favors high-priced housing, factories, hotels, and
other busi-nesses over protecting environmentally sensitive areas
and providing low-cost housing, again because most local
governments depend on property taxes for their revenue.
thinking about Property taxes
What alternatives to depending on property taxes for revenue do
local governments have? Which, if any, of these alterna-tives would
you support? Explain.
In addition, overly strict zoning can discourage innovative
approaches to solving urban problems. For example, the pattern in
the United States and in some other countries has been to prohibit
businesses in resi-dential areas, which increases suburban sprawl.
Some urban planners want to return to mixed-use zoning to help
reduce this problem. In the 1970s, Portland, Ore-gon, managed to
cut driving and gasoline consumption by resurrecting the idea of
neighborhood grocery stores (see Case Study, p. 604).
Smart Growth Works Smart growth is one way to encourage more
envi-ronmentally sustainable development that requires less
dependence on cars, controls and directs sprawl, and reduces
wasteful resource use (see Case Study, p. 604). It recognizes that
urban growth will occur, but at the same time, it uses zoning laws
and other tools to channel that growth into areas where it can
cause less harm.
Smart growth can discourage sprawl, reduce traffic, protect
ecologically sensitive and important lands and waterways, and
develop neighborhoods that are more enjoyable places in which to
live. Figure 22-19 (p. 604) lists popular smart growth tools that
we can use to pre-vent and control urban growth and sprawl.
Curitiba, Brazil, (Core Case study) has also used a variety of
such strategies to control sprawl and reduce dependence on the car.
Several stud-ies have shown that most forms of smart growth
pro-vide more jobs and spur more economic renewal than does
conventional economic growth. (See The Habit-able Planet, Video 5,
at www.learner.org/resources/series209.html to learn the use of
smart growth for controlling population growth and urban sprawl in
Cape Cod, Massachusetts [USA].)
China has taken the strongest stand of any country against urban
sprawl. The government has designated 80% of the country’s arable
land as fundamental land. Building on such land requires approval
from local and provincial governments and from the State Council,
the central government’s chief administrative body. This is
somewhat like having to get congressional approval for a new
subdivision in the United States. However, China’s approach goes to
an extreme; developers violat-ing the rules can face the death
penalty.
Many European countries have been successful in discouraging
urban sprawl in favor of compact cities.
ConCEPT 22-4 603
-
604 ChaPTEr 22 Cities and Sustainability
They have controlled development at the national level and
imposed high gasoline taxes to discourage car use and to encourage
people to live closer to workplaces and shops. High taxes on
heating fuel encourage peo-ple to live in apartments and small
houses. These gov-ernments have used most of the resulting gasoline
and heating fuel tax revenues to develop efficient train and other
mass transit systems within and between cities.
■ Case study
Smart Growth in Portland, OregonThe U.S. city of Portland,
Oregon, has used smart growth strategies to control sprawl and
reduce dependence on automobiles. Since 1975, Portland’s population
has grown by about 50%, but its urban area has expanded
by only 2%. In addition, abundant green space and nat-ural
beauty is just 20 minutes from downtown.
The city has built an efficient light-rail and bus sys-tem that
carries 45% of all commuters to downtown jobs—a much higher
percentage than in most U.S. cit-ies. By reducing traffic, Portland
was able to convert a former expressway and huge parking lot into a
water-front park.
Portland encourages clustered, mixed-use neighbor-hood
development, with stores, light industries, profes-sional offices,
high-density housing, and access to mass transit, which allows most
people to meet their daily needs without a car. In addition to its
excellent light-rail and bus lines, Portland has further reduced
car use by developing an extensive network of bike lanes and
walk-ways. Employers are encouraged to give their employ-ees bus
passes instead of providing parking spaces.
Since 1975, the city’s air pollution has decreased by 86%.
Portland is frequently cited as one of the most livable cities in
the United States and in 2008, environ-mental researcher and writer
Elizabeth Svoboda ranked it as the greenest city in the United
States. In order, the next nine greenest U.S. cities were San
Francisco, California; Boston, Massachusetts; Oakland, California;
Eugene, Oregon; Cambridge, Massachusetts; Berkeley, California;
Chicago, Illinois; Austin, Texas; and Minne-apolis, Minnesota.
thinking about Portland and Curitiba
How is the urban strategy of Portland, Oregon, simi-lar to that
of Curitiba, Brazil (Core Case study)? How do their strategies
differ?
Preserving and Using Open Space One way to preserve open space
outside a city is to draw an urban growth line around each
community and to allow no urban development outside that boundary.
This urban growth boundary approach is used in the U.S. states of
Oregon, Washington, and Tennessee. However, the Seattle region of
Washington State found that using a growth boundary to increase
housing densities inside the line had the unintended effect of
encouraging low-density housing and sprawl in rural and natural
areas just beyond the boundary.
Another approach is to surround a large city with a greenbelt—an
open area reserved for recreation, sus-tainable forestry, or other
nondestructive uses. Satellite towns are often built outside these
greenbelts. Ideally, the outlying towns are self-contained, not
sprawling, and are linked to the central city by a public transport
system that does minimal damage to the greenbelt.
Many cities in western Europe and the Canadian cit-ies of
Toronto and Vancouver have used this approach. By establishing a
greenbelt outside its urban growth boundary, Seattle, Washington,
could have minimized urban sprawl just beyond that line. Greenbelt
areas can
Limits and Regulations
Limit building permits
Draw urban growth boundaries
Create greenbelts around cities
ZoningPromote mixed use of housing and small businesses
Concentrate development along mass transportation routes
PlanningEcological land-use planning
Environmental impact analysis
Integrated regional planning
Protection
Preserve open space
Buy new open space
Prohibit certain types of development
Taxes
Tax land, not buildings
Tax land on value of actual use instead of on highest value as
developed land
Tax Breaks
For owners agreeing not to allow certain types of
development
For cleaning up and developing abandoned urban sites
Revitalization and New Growth
Revitalize existing towns and cities
Build well-planned new towns and villages within cities
Smart Growth Tools
Solutions
Figure 22-19 We can use these smart growth or new urbanism tools
to prevent and control urban growth and sprawl. Questions: Which
five of these tools do you think would be the best methods for
preventing or controlling urban sprawl? Which, if any, of these
tools are used in your community?
-
provide vital ecological services such as absorption of CO2 and
other air pollutants, which can make urban air more breathable and
help to cut a city’s contribution to projected climate
disruption.
A more traditional way to preserve large blocks of open space is
to create municipal parks. Examples of large urban parks in the
United States are Central Park in New York City (Figure 22-20);
Golden Gate Park in San Francisco, California; and Grant Park in
Chicago, Illinois.
In 1883, officials in the U.S. city of Minneapolis, Minnesota,
vowed to create “the finest and most beau-tiful system of public
parks and boulevards of any city in America.” In the eyes of many,
this goal has been achieved. Today, the city has 170 parks
strategically located so that most homes in Minneapolis are within
six blocks of a green space. Similarly, Jacksonville, Florida
(USA), has a high ratio of parkland to total city area.
Figure 22-20 With almost 344 hectares (850 acres) that include
woodlands, lawns, and small lakes and ponds, New York City’s
Central Park is a dramatic example of a large open space in the
center of a major urban area.
age
foto
stoc
k/Su
perS
tock
22-5 How Can Cities Become More Sustainable and Livable?
ConCept 22-5 an ecocity allows people to choose walking, biking,
or mass transit for most transportation needs; to recycle or reuse
most of their wastes; to grow much of their food; and to protect
biodiversity by preserving surrounding land.
▲
New Urbanism Is Growing Since World War II, the typical approach
to suburban housing development in the United States has been to
bulldoze a tract of woods or farmland and build rows of houses on
standard-size lots (Figure 22-21, middle, p. 606). Many of these
developments and their streets, with names like Oak Lane, Cedar
Drive, Pheasant Run, and Fox Valley, are named after the trees and
wildlife they displaced.
In recent years, builders have increasingly used a pattern known
as cluster development, in which high- density housing units are
concentrated on one portion
of a parcel, and the rest of the land (often 30–50%) is used as
commonly shared open space (Figure 22-21, bottom). When this is
done properly, residents can enjoy more open and recreational space
within aesthet-ically pleasing surroundings. They might also see
lower heating and cooling costs because some walls are shared in
multiple-family dwellings. Developers can also cut their costs for
site preparation, roads, utilities, and other forms of
infrastructure.
Some communities are going further and using the goals of new
urbanism, which is a modern form of what could be called old
villageism, to develop entire villages
ConCEPT 22-5 605
-
606 ChaPTEr 22 Cities and Sustainability
and promote mixed-use neighborhoods within existing cities.
These goals include:
• walkability, with most stores and recreational activi-ties
within a 10-minute walk of any home.
• mixed-use and diversity, which provides a blend of
pedestrian-friendly shops, offices, apartments, and homes to
encourage people of different ages, classes, cultures, and races to
move into the villages.
• quality urban design, emphasizing beauty, aesthetics, and
architectural diversity.
• environmental sustainability based on development with minimal
environmental impact.
• smart transportation, with well-designed train and bus systems
connecting neighborhoods, towns, and cities.
A prominent example of new urbanism is a new sub-urb of
Freiburg, Germany, called Vauban (see the Case Study that follows).
Examples of new urban villages in the United States are Mayfaire,
in Wilmington, North Carolina; Mizner Place in Boca Raton, Florida;
Middle-
ton Hills near Madison, Wisconsin; Yardley, Pennsyl-vania;
Kentlands in Gaithersberg, Maryland; Valencia, California (near Los
Angeles); and Stapleton, Colorado (built on an old airport site in
Denver).
researCh Frontier
Evaluating, improving, and implementing more environmen-tally
sustainable new urbanism; see www.cengage.com/ login.
thinking about new urbanism
Is there an example of new urbanism in or near the place where
you live? Would you like to live in such a village? Explain.
■ Case study
The New Urban Village of VaubanSince the early 1990s, the city
of Freiburg, Germany, has given high priority to controlling urban
sprawl. As part of that effort, the city planned a new suburb
called Vauban, completed in 2006 and designed to be virtually free
of cars.
A small minority of homeowners in Vauban have cars. Street
parking, driveways, and garages are gen-erally forbidden in the
village. Car owners have two places to park—two large garages on
different sides of town—and a parking space costs $40,000.
Vauban is designed so that each of its 5,000 homes is located
within easy walking distance of train lines that connect to
surrounding communities. Stores, banks, res-taurants, and schools
are also within walking distance of all homes. The town has
numerous bike paths and a car-sharing club. Mass transit allows
residents to work or shop in Freiburg, a city of about 200,000
people.
The community has no single-family homes. People live in stylish
row houses within four- and five-story buildings that were designed
with an emphasis on use of passive solar energy (Figure 16-11,
left, p. 409). The shared walls between these homes help them to be
highly energy-efficient. In addition, 65% of the energy used for
electricity and heating in Vauban comes from solar power or from an
efficient central cogeneration plant that runs on wood chips and
provides central heating and electric power for Vauban residents.
Vau-ban’s planners and designers hope that some of the best
features of this urban ecovillage will be widely used in other
planned communities around the world.
thinking about Vauban and Curitiba
What are two differences between Curitiba, Brazil, and Vauban,
Germany, in terms of how each is trying to be more sustainable?
Which model do you think would work better for the community in
which you live or go to school?
Figure 22-21 These models compare a conventional housing
devel-opment (middle) with a cluster housing development (bottom).
With a cluster development, houses, town houses, condominiums, and
two- to six-story apartments are built on part of the tract. The
rest, typically 30–50% of the area, is left as open space for
wildlife pre-serves, parks, and walking and cycling paths.
Undeveloped land
Marsh
Pond
Creek
Cluster
Cluster
Typical housing development
Cluster housing development
Creek
-
The Ecocity Concept: Cities for People, Not Cars According to
most environmentalists and urban plan-ners, the primary problem
with large cities is not urban growth but our failure to make them
more sustainable and livable. These same environmentalists and
planners call for us to make new and existing urban areas more
self-reliant, sustainable, and enjoyable places to live through
good ecological design. (See the Guest Essay on this topic by David
Orr on the website for this chapter.)
New urbanism is a step in the right direction, but we can go
further by creating more environmentally sustainable cities, called
ecocities or green cities, which emphasize the following goals
built around the three principles of sustainability (See back
cover):
• Use solar and other locally available, renew-able energy
resources, and design buildings to be heated and cooled as much as
possible by natural means.
• Build and redesign cities for people, not for cars.
• Use energy and matter resources efficiently.
• Prevent pollution and reduce waste.
• Reuse, recycle, and compost 60–85% of all munici-pal solid
waste.
• Protect and encourage biodiversity by preserving undeveloped
land and protecting and restoring natural systems and wetlands in
and around cities.
• Promote urban gardens, farmers markets, and
community-supported agriculture.
• Use zoning and other tools to keep urban sprawl at
environmentally sustainable levels.
An ecocity is a people-oriented city, not a car-ori-ented city.
Its residents are able to walk, bike, or use low-polluting mass
transit for most of their travel. Trees and plants adapted to the
local climate and soils are planted throughout the city to provide
shade, beauty, and wildlife habitats, and to reduce air pollution,
noise, and soil erosion. Small organic gardens and a variety of
plants adapted to local climate conditions often replace
monoculture grass lawns.
An ecocity’s buildings, vehicles, and appliances meet high
energy-efficiency standards. Some planners suggest that ecocities
could evolve to become energy-indepen-dent. They see homes and
businesses containing their own power plants, with solar panels and
wind turbines on many roofs providing power to the buildings. These
home power plants could also be used to recharge plug-in hybrid
cars (Figure 16-6, right, p. 403) and all-electric vehicles. In
addition, food waste and lawn and garden trimmings could be put
into digesters to make natural gas for heating and cooking.
In an ecocity, abandoned lots and industrial sites are cleaned
up and restored, and put to new uses. For example, in Curitiba,
Brazil, (Core Case study) an old gunpowder storage building was
con-
verted into a theatre, a foundry into a shopping mall, the old
railroad station into a railway museum, and a quarry into an
amphitheatre.
In Curitiba and other cities, polluted creeks and rivers have
been cleaned up and nearby forests, grass-lands, wetlands, and
farms have been preserved. Parks are easily available to everyone.
Curitiba also employs a municipal shepherd who tends a flock of
sheep, which munch the grass in the parks. Thus, instead of
spending money and energy on mowing, the city uses its grass as a
resource. Meat and wool from the sheep are peri-odically sold to
help the city pay for social programs and the sheep manure is used
as organic fertilizer.
In an ecocity, much of the food that people eat comes from
nearby organic farms, solar greenhouses, community gardens, and
small gardens grown on roof-tops, in yards, and in windows boxes.
The UN Food and Agriculture Organization (FAO) has estimated that
such urban food production supplies food for about one-fifth of the
world’s 3.4 billion urban residents. The FAO proj-ects that with
organized programs and financial incen-tives, much more of the
world’s food could be grown in or near cities. Experts project that
rising oil prices will increase food shipping costs, which could
cause a shift from globalized agriculture to more localized food
pro-duction in urban areas (Science Focus, p. 608).
Finally, an ecocity provides plenty of educational opportunities
for its residents by teaching them about environmental problems and
solutions. This includes not only school curricula, but also
botanical gardens, humane and sustainable zoos and aquaria, and
outdoor learning centers. Curitiba, Brazil (Core Case study), has
established Lighthouses of Knowl-edge—free educational centers
located strategically around the city. They include libraries,
Internet access, job training, and other resources.
This may sound like a futuristic dream, but ecocities are real,
as you saw in this chapter’s opening Core Case study. An example of
an emerging ecocity is Bogotá, Colombia. Its transformation began
in 1998 when Enrique Peñalosa was elected mayor. His major goal was
to improve life for the 5.6 million city res