Chapter 22 Quiz
Know the details of the following disadvantages of urbanization: Land area used compared to resource consumption
Although urban populations occupy only about 2% of the earth's land area, they consume 75% of its resources and produce 75% of all carbon dioxide emissions from human activities, according to the Worldwatch Institute. Because of this high resource input of food, water, and materials and the resulting high waste output, most of the world's cities have huge ecological footprints and are not self-sustaining systems. By concentrating people in a small area urbanization helps to preserve some of the earth's biodiversity. But at the same time large areas of land that must be disturbed and degraded to provide urban dwellers with food, water, energy, minerals, and other resources. This decreases and degrades the earth's overall biodiversity. Thus, urban areas have huge ecological footprints that extend far beyond their boundaries. Recent studies also reveal that most urban dwellers live in an artificial environment that isolates them from forests, grasslands, streams, and other natural areas that contain the world's biodiversity. As a result, many of them tend to have little passion for protecting biodiversity and other forms of natural capital that support their lives and the cities where they live.
How has the percentage of the US population living in cities changed since 1800?
Between 1800 and 2008, the percentage of the U.S. population living in urban areas increased from 5% to 79%.
What other alternatives to cars can cities promote to reduce the use of cars?
Bicycles; mass transit rail; buses; rapid rail. 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. Leaders in developing 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. There are several alternatives to motor vehicles, each with its own advantages and disadvantages. One widely used alternative is the bicycle. 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. Also growing is the use of electric bicycles with lightweight electric motors. Bicycles are widely used for urban trips in many countries. Bicycling and walking account for about a third of all urban trips in the Netherlands and in Copenhagen, Denmark. Japan and the Netherlands strive to integrate travel by bicycle and by commuter rail by providing secure bicycle parking at rail stations. 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. Heavy-rail systems (subways, elevated railways, and metro trains) and light-rail systems (streetcars, trolley cars, and tramways) have their advantages and disadvantages. At one time, all major U.S. cities had effective light-rail systems, but they were dismantled to promote car and bus use. However, such systems are being built again in several U.S. cities. An outstanding example is the lightrail system in Minneapolis, Minnesota, which opened in 2005 and surprised planners by drawing 50% more riders than they had expected. The rail system in Hong Kong is one of the world's most successful, primarily because the city is densely populated, which means that half the population can walk to a subway station within 5 minutes. And owning a car is 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. Curitiba, Brazil, has one of the world's best bus rapid transit systems, which carries about 2.3 million passengers a day. But the system is now feeling the strain of population pressures, and car use is increasing in Curitiba. Transportation officials there are considering building a light-rail system to help carry the rapidly growing passenger load. Similar bus rapid transit systems have been developed in Bogotá, Colombia, and are being planned for Mexico City; São Paulo, Brazil; 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. In western Europe and Japan, high-speed bullet trains travel between cities 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. In 2004, Shanghai, China, began operating the world's first commercial high-speed magnetic levitation train between its airport and downtown. The train, suspended in air slightly above the track and propelled forward by strong repulsive and attractive magnetic forces, travels much faster than bullet trains do. In the United States, a high-speed bullet train network could replace airplanes, buses, and private cars for most medium-distance travel between major American cities. Critics say such a system would cost too much in government subsidies. But this argument ignores the fact that motor vehicle transportation receives government (taxpayer) subsidies of $300-600 billion per year in the United States. The Urban Land Institute estimates that building a U.S. system comparable to the best European systems would cost $250 billion per year over 2 decades.
Know the details of the following disadvantages of urbanization: urban heat island
Cities generally are warmer, rainier, foggier, and cloudier than suburbs and nearby rural areas. The enormous amount of heat generated by cars, factories, furnaces, lights, air conditioners, and heat-absorbing dark roofs and streets in cities creates an urban heat island that is surrounded by cooler suburban and rural areas. As cities grow and merge, their heat islands merge, which can reduce the natural dilution and cleansing of polluted air. In addition to changing local and regional climate, the urban heat island effect in hot climates puts heat stress on humans and many other organisms, can increase the formation of photochemical smog, and greatly increases dependence on air conditioning for cooling. This in turn increases energy consumption, greenhouse gas emissions, and other forms of air pollution in a positive feedback loop.
Know definitions & how each can be an advantage in creating sustainable cities: Zoning
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 designated for certain uses. Zoning can be used to control growth and protect areas from certain types of development. For example, cities such as Portland, Oregon (USA), and Curitiba, Brazil, have used zoning to encourage high-density development along major mass transit corridors to reduce automobile use and air pollution.
Know definitions & how each can be an advantage in creating sustainable cities: Urban growth boundary
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 those boundaries. 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 growth boundaries to increase housing densities inside the boundaries had the unintended effect of encouraging low-density housing and sprawl in rural and natural areas just beyond the growth boundaries.
Know the details of the following disadvantages of urbanization: Infectious diseases
In addition, high population densities in urban areas can increase the spread of infectious diseases, especially where there are no adequate drinking water and sewage systems.
Know definitions & how each can be an advantage in creating sustainable cities: Cluster development
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, with the rest of the land (often 30-50%) used for commonly shared open space. When this is done properly, residents live with more open and recreational space, aesthetically pleasing surroundings, and lower heating and cooling costs because some walls are shared. And developers can cut their costs for site preparation, roads, utilities, and other forms of infrastructure.
What is urban sprawl? What factors have contributed to urban sprawl in the US?
In the United States and some other countries, urban sprawl—the growth of low-density development on the edges of cities and towns—is eliminating surrounding agricultural and wild lands. It results in a far-flung hodgepodge of housing developments, shopping malls, parking lots, and office complexes that are loosely connected by multilane highways and freeways. Six major factors promoted urban sprawl in the United States. First, ample land was available for most cities to spread outward. Second, federal government loan guarantees for new single-family homes for World War II veterans stimulated the development of suburbs starting around 1950. Third, low-cost gasoline and federal and state funding of highways encouraged automobile use and the development of outlying tracts of land. Fourth, tax laws encouraged home ownership. Fifth, most state and local zoning laws favored large residential lots and separation of residential and commercial areas. And sixth, most urban areas consist of multiple political jurisdictions, which rarely work together to develop an overall plan for managing urban growth. In a nutshell, urban sprawl is the product of affordable land, automobiles, cheap gasoline, and poor urban planning. It has caused or contributed to a number of environmental problems. Because of nonexistent or inadequate mass transportation in most such areas, sprawl forces people to drive everywhere and, in the process, to emit greenhouse gases and other forms of air pollution. Sprawl has decreased energy efficiency, increased traffic congestion, and destroyed prime cropland, forests, and wetlands. It has also led to the economic death of many central cities as people and businesses moved out of these areas.
Know the details of the following disadvantages of urbanization: Lack of vegetation
In urban areas, most trees, shrubs, or other plants are destroyed to make way for buildings, roads, parking lots, and housing developments. So most cities do not benefit from vegetation that would absorb air pollutants, give off oxygen, cool the air through transpiration, provide shade, muffle noise, provide wildlife habitats, and give aesthetic pleasure. As one observer remarked, "Most cities are places where they cut down most of the trees and then name the streets after them."
What environmental problems are faced by Mexico City?
Mexico City suffers from severe air pollution, close to 50% unemployment, deafening noise, overcrowding, traffic congestion, inadequate public transportation, and a soaring crime rate. More than one-third of its residents live in slums called barrios or in squatter settlements that lack running water and electricity. At least 3 million people have no sewer facilities. As a consequence, huge amounts of human waste are deposited in gutters, vacant lots, and open sewers 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 pollution problems because of a combination of factors: too many cars, polluting factories, a 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—conditions 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. The city's air and water pollution cause an estimated 100,000 premature deaths per year. Writer Carlos Fuentes has nicknamed it "Makesicko City." Large-scale water withdrawals from the city's aquifer 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. The city's growing population increasingly relies on pumping in water from as far away as 150 kilometers (93 miles) and then using large amounts of energy to pump the water 1,000 meters (3,300 feet) uphill to reach the city.
Know the details of the following disadvantages of urbanization: noise & light pollution
Most urban dwellers are subjected to noise pollution: any unwanted, disturbing, or harmful sound that impairs or interferes 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. Sound pressure becomes damaging at about 85 dbA and painful at around 120 dbA. At 180 dbA it can kill. Prolonged exposure to sound levels above 85 dbA can cause permanent hearing damage. About one of every eight children and teens in the United States has some permanent hearing loss, mostly from listening to music at loud levels. Also, the artificial light created by cities hinders astronomers from conducting their research and makes it difficult for casual observers to enjoy the night sky. Light pollution also affects some plant and animal species. For example, endangered sea turtles lay their eggs on beaches at night and require darkness. And each year, large numbers of migrating birds, lured off course by the lights of high-rise buildings, fatally collide with the buildings.
Know the advantages & disadvantages of cars (environmental & economic)
Motor vehicles provide mobility and offer a convenient and comfortable way to get from one place to another. They also are symbols of power, sex appeal, social status, and success for many people. And much of the world's economy is 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 the environment. Globally, automobile accidents kill approximately 1.2 million people a year—an average of nearly 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 wars in the country's history. Motor vehicles are the world's largest source of outdoor air pollution, which causes 30,000-60,000 premature deaths per year in the United States, according to the Environmental Protection Agency. They are also the fastest-growing source of climate-changing carbon dioxide emissions. In addition, they account for two-thirds of the oil used in the form of gasoline in the United States and one-third of the world's oil consumption. Motor vehicles have helped to create urban sprawl and the car commuter culture. At least a third of urban land worldwide and half 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. Another problem is congestion. As the number of cars increases in an urban area, at some point they contribute to immobility not mobility. If current trends continue, U.S. motorists will spend an average of 2 years of their lives in traffic jams, as streets and freeways, begin to look like parking lots. Traffic congestion in some cities in developing countries is much worse. Commuter distances increase as cities sprawl out. Building more roads may not be the answer. Many analysts agree with economist Robert Samuelson that "cars expand to fill available concrete."
How can tolls reduce urban congestion and automobile use?
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—especially during peak traffic times. Densely populated Singapore is rarely congested, because it auctions the rights to buy a car, and car owners must pay a high tax to use any of the roads leading into the city center. London, England, which has a similar road congestion fee of $49 per day on gas-guzzling cars (with no fee for fuel-efficient vehicles), has reduced the number of cars entering the city during the day. Stockholm, Sweden, and Milan, Italy, have also imposed stiff fees for motor vehicles entering their central cities. And in an effort to reduce fuel use, CO2 emissions, and local air pollution, the mayors of the U.S. cities of New York City and San Francisco, California, are considering such vehicle entry fees, and have announced that all taxis in their cities must be hybrid vehicles by 2012. Paris, France, one of Europe's most congested cities, has upgraded its mass transit system and created express lanes for buses and bicycles on main thoroughfares while reducing the lanes for cars. The city also established a program with almost 21,000 bikes available for rental at 1,450 rental stations throughout the city at a cost of just over $1 a day. In Germany, Austria, Italy, Switzerland, and the Netherlands more than 300 cities have car-sharing networks. 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 carbon dioxide emissions by 40-50%. Car-share companies have sprouted up in the United States since 2000 in cities such as Portland, Oregon, and San Diego and Los Angeles in California, among others.
Know the details of the following disadvantages of urbanization: Water issues
As cities grow and water demands increase, expensive reservoirs and canals must be built and deeper wells must be drilled. This can deprive rural and wild areas of surface water and deplete groundwater.
Know the details of the following disadvantages of urbanization: Concentration of water & air pollution
Flooding also tends to be greater in some cities, because they are built on floodplains near rivers or along low-lying coastal areas subject to natural flooding. And covering land with buildings, asphalt, and concrete causes precipitation to run off quickly and overload storm drains. In addition, urban development has often destroyed or degraded wetlands that have served as natural sponges to help absorb excess water. Many of the world's largest cities face another threat because they are located in coastal areas that could be partially flooded some time in this century as sea levels rise due to projected climate change. Other cities in arid areas that depend on withdrawing water from rivers and the reservoirs behind dams may face severe water shortages as global warming reduces the mountaintop glaciers and snow that melt each year to provide river flows and fill reservoirs. As a result, in some hotspot arid areas in the western United States fed by the Colorado River and California's water distribution system, irrigated agriculture may have to be abandoned. And urban populations in some of these areas may drop sharply as people are forced to move elsewhere because of a lack of water. Greater reliance on groundwater is not an option in many areas where aquifers are being depleted faster than they are being replenished. 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 pollution is produced in a smaller area and cannot be dispersed and diluted as readily as pollution produced in rural areas. The concentration of motor vehicles and industry in urban centers, where about three-fourths of the world's CO2 from human-related sources are emitted, causes disruption of local and regional portions of the carbon cycle. This urban concentration also disrupts the nitrogen cycle because of emissions of large quantities of nitrogen oxides, which play a key role in the formation of photo chemical smog, and nitric acid and nitrates, which are major components of acid deposition in urban areas and beyond. And nitrogen nutrients in urban runoff and discharges from urban sewage treatment plants can disrupt the nitrogen cycle in nearby lakes and other bodies of water and cause excessive eutrophication.
What are the major trends in urban population dynamics
Four major trends in urban population dynamics do seem clear, and they are important for understanding the problems and challenges of urban growth. First, the proportion of the global population living in urban areas is increasing. Between 1850 and 2008, the percentage of people living in urban areas increased from 2% to almost 50% and could reach 60% by 2030. About 88% of this growth will occur in already overcrowded and stressed cities in developing countries, where 44% of the people live in urban areas. Second, urban areas are expanding rapidly in number and size. Each week 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. And there are 18 megacities or megalopolises—cities with 10 million or more people—up from 8 in 1985. Fifteen of them are in developing countries. Such megacities will soon be eclipsed by hypercities with more than 20 million people each. So far, Tokyo, Japan, with 26.5 million people, is the only city in this category. But according to U.N. projections, Mumbai (formerly Bombay) in India, Lagos in Nigeria, Dakar in Bangladesh, and São Paulo in Brazil will become hypercities by 2015. Third, urban growth is much slower in developed countries than in developing countries. Still, developed countries, now with 75% urbanization, are projected to reach 81% urbanization by 2030. Fourth, poverty is becoming increasingly urbanized, mostly in developing countries. The United Nations estimates that at least 1 billion people in developing countries live in crowded and unsanitary slums and shantytowns within most cities or on their outskirts; within 30 years this number may double. If you visit a poor area of a typical city in a developing country, your senses may be overwhelmed by a chaotic but vibrant crush of people, vehicles of all types, congestion, noise, traffic jams, and smells, including smoke from burning trash and 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.
Know definitions & how each can be an advantage in creating sustainable cities: Greenbelt
Some cities provide open space and control urban growth by surrounding a large city with a greenbelt—an open area reserved for recreation, sustainable 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 cities of Toronto and Vancouver have used this approach. Seattle, Washington, could have minimized urban sprawl just beyond its urban grow boundary by establishing a greenbelt outside the boundary. Greenbelt areas can 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 climate change.
How would full-cost pricing for gasoline work? Why would it be difficult to acheive in the US?
Some environmental scientists and economists suggest that one way to reduce the harmful effects of automobile use is to make drivers pay directly for most environmental and health costs of their automobile use—a user-pays approach, based on honest environmental accounting. One way to phase in such full-cost pricing would be to charge a tax 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 (p. 404). Gradually phasing in such a tax would spur the use of more energy-efficient motor vehicles and mass transit and decrease dependence on imported oil, thereby increasing economic and military security. It would also reduce pollution and environmental degradation and help to slow climate change. Proponents of this approach urge governments to use gasoline tax revenues to help finance mass transit systems, bike lanes, and sidewalks as alternatives to cars. They also urge reduction of taxes on income, wages, and wealth to offset the increased taxes on gasoline. Such a tax shift would make higher gasoline taxes more politically acceptable. Europe, Japan, Singapore, and some rapidly developing Chinese cities have developed rapid mass transit systems within and between urban areas and networks of sidewalks and bike lanes in urban and suburban areas. Analysts warn that countries such as the United States, which lags in developing such systems, will face great economic difficulties in the face of a projected decline in oil production and rapidly rising oil and gasoline prices. The end result could be mass abandonment of sprawling car-dependent suburbs and shopping centers as they become environmentally and economically unsustainable. Heavily taxing gasoline is difficult in the United States, for three reasons. First, it faces strong opposition from the public, which is largely unaware of the huge hidden costs they are paying for gasoline, and from powerful transportation-related industries such as oil and tire companies, road builders, car makers, and real estate developers. Second, fast, efficient, reliable, and affordable mass transit options and bike lanes are not widely available in most of the United States. And third, the dispersed nature of most U.S. urban areas makes people dependent on cars. 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.
In what ways can urban areas grow?
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 opportunities, better health care, entertainment, and freedom from religious, racial, and political conflicts. Some are also pushed from rural to urban areas by factors such as poverty, lack of land for growing food, declining agricultural jobs, famine, and war. People are also pushed and pulled to cities by government policies that favor urban over rural areas. For example, developing countries tend to spend most of their budgets on economic development and job creation in urban areas and especially in capital cities where their leaders live. Some governments establish lower food prices in urban areas, which rewards city dwellers, helps to keep leaders in power, and attracts the rural poor.
What are some advantages to urbanization?
Urbanization has many benefits. From an economic stand point, cities are centers of economic development, 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 have lower infant mortality rates and fertility rates. They also have better 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 advantages. 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 biodiversity by reducing the stress on wildlife habitats. And central cities can save energy if residents rely more on energy-efficient mass transportation, walking, and bicycling.
What are some environmental hazards associated with shantytowns/ squatter settlements? How can governments improve these conditions?
When it rains, the usually unpaved alleys can become clogged with dead rats, garbage, and sewage. Poor people living in shantytowns and squatter settlements usually lack clean water supplies, sewers, electricity, and roads, and are subject to severe air and water pollution and hazardous wastes from nearby factories. Many of these settlements are in locations especially prone to landslides, flooding, or earthquakes. Many city governments regularly bulldoze squatter shacks and send police to drive illegal settlers out. The people usually move back in or develop another shantytown somewhere else. There are ways in which 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 encouraging investment in small towns. Governments can also designate land for squatter settlements and supply them with clean water, as Curitiba, Brazil, has done. In addition to providing access to safe drinking water, they can place composting toilets, which require no water, at locations throughout such settlements. Guaranteeing regular bus service enables workers who live in such settlements to travel to and from their workplaces. In Brazil and Peru, governments legally recognize existing slums (favelas) and grant legal titles to the land. This is based on understanding that the poor will usually improve their living conditions and develop schools, day care centers, and other social improvements once they know they can stay there.