Urbanization

Curitiba, Brazil: an ecocity In 1969, the city focused on mass transit and now has the world’s best bus system 70% of people use mass transit All high-rise buildings devote the bottom 2 floors to stores (reduces need to travel) Recycles 70% of paper and 60% of metal, glass, and plastic The city uses old buses as roving classrooms to teach skills, and as health clinks and day-care centers The poor get free medical care and can exchange recyclables for food and bus tokens The city also provides free taps of safe water throughout poor areas

Why do people move to urban centers? As the industrial revolution created more jobs in urban centers, fewer people were needed on farms Urbanization is the shift of population from the countryside to towns and cities in developed countries, urbanization has slowed, because 3 out 4 people already live in cities, towns, and suburbs (smaller communities that ring cities) In developing nations, urbanization is drastically increasing

Urban Cities Today Today, 46 cities hold more then 5 million people, and 20 cities hold more than 10 million people Less than 5% of North American urban dwellers like in large cities; most live in smaller cities such as Portland or Austin

Major Urban Regions in the US Fig. 25-6 p. 665

Why is urban growth so rapid? More people are moving from farms to cities than are moving from cities to farms The human population overall is growing Most fast growing cities today are in the developing world Many are facing overcrowding, pollution, and poverty

Practice Question The two continents with the greatest increase in urbanization are North America and Africa South America and Australia Africa and Asia Asia and North America Europe and South America

The suburbs As cities become more crowded, unemployment rises and poverty and crime increase Many affluent city dwellers chose to move outward to the cleaner, less crowded, and more park-like suburban communities surrounding cities Suburbs provide more space per person, but need more roads, have traffic, and large-scale habitat destruction

Urban Sprawl Sprawl is the spread of low-density urban or suburban development outward from an urban center

Urban Sprawl There are two main components of sprawl Human population growth Per capita land consumption is increasing

Practice Question The growth of suburbs and urban sprawl were primarily facilitated by The development of indoor plumbing The proliferation of automobiles A lack of vested ecosystems Rebates and other legislative incentives A decrease in the cost and time required for house construction

Negatives to sprawl Transportation: people mostly drive cars due to a lack of transportation options Pollution: CO2 emissions increase, as do NO2 and SO2 emissions Water pollution is estimated to be 16 times greater on paved areas than from vegetated areas

Negatives to sprawl Health: some studies indicate that sprawl promotes physical inactivity This leads to other health issues Land use: more land is developed and less is left as forests, fields, or farmland Economics: tax dollars are spent on new infrastructure on the outskirts of cities (ex: roads, telephone lines, sewers)

Advantages to urbanization Economics: cities are centers of economic development and jobs Health: lower infant mortality rates, long lives, and better access to health care Environmental: recycling is more economically feasible, preserves biodiversity

Disadvantages to urbanization Unsustainable systems: occupy 2% of land area and use ¾ of earth’s resources Lack of plants: most trees, shrubs, and other plants are destroyed Water problems: cities have a high demand for water Also, flooding problems occur

Urban Areas: Inputs and Outputs Fig. 25-11 p. 669

Practice Question All of the following are environmental advantages of urbanization as compared to rural living EXCEPT Increased feasibility of recycling Increased per capita expenditures on environmental expenditures Reduced use of land Reduced stress on wildlife habitats Reduced climactic impact

Disadvantages to urbanization Pollution and health problems: high density and resource consumption leads to high levels of air and water pollution, as well as waste disposal issues Also increases the spread of infectious diseases Climate and artificial light: cities are warmer, rainier, foggier, and cloudier than suburbs Creates large amounts of artificial light Poverty and social problems

Urban Heat Island The large amounts of heat generated by cars, factories, furnaces, lights, etc create an “urban heat island” This phenomenon describes urban and suburban temperatures that are 2 to 10°F (1 to 6°C) hotter than nearby rural areas

Case study: Mexico City 19 million people live there, with 400,000 arriving each year Severe air pollution, 50% unemployment, deafening noise, overcrowding, traffic congestion, inadequate public transportation, and a high crime rate 1/3 of the residents live in slums with no running water and electricity 3 million people have no sewers facilities—large amounts of human waste are all around the city Has one of the world’s worst smog problems

Case study: Mexico City Air and water pollution cause 100,000 premature deaths per year Water demands have drained the aquifers so much that parts of the city have subsided 30 feet The city has made some progress with pollution in recent years and has started to plant trees

City Planning City planning is the professional pursuit that attempts to design cities so as to maximize their efficiency, functionality, and beauty Chicago was the first American city that was thoroughly planned

City Zoning In zoning, various parcels of land are designated for certain uses Zoning can be used to control the growth of a city Zoning is not very effective in protecting the environment, because it is not a concern for politicians when making decisions

Preserving open space Urban growth boundary model encourages certain types of development that prevents destruction of important environmental areas The traditional method is to preserve large blocks of open space as parks

Practice Question A city is immersed in a brownish tinted smog. What can be inferred from this observation? UV rays had nothing to do with the formation of this brownish haze The automobiles in the city alone are responsible for this brownish haze A nearby coal-fired factory is responsible for this brownish haze Nitrogen dioxide is responsible for this brownish haze

Smart Growth Smart growth is a city planning concept in which a community’s growth is managed in ways that limit sprawl and improve residents’ quality of life Mix land uses Take advantage of compact building design Create a range of housing opportunities

Smart Growth Create walkable neighborhoods Foster distinctive, attractive communities Preserve open space, farmland, natural beauty, and critical environmental areas Strengthen and direct development towards existing communities Provide a variety of transportation choices Make development decisions predictable, fair, and cost-effective Encourage community collaboration in decisions

Transit Options in Cities As long as an urban center is large enough to support the infrastructure, mass transit options are cheaper, more energy-efficient, and cleaner than roadways

Pros Cons Rail Buses Bikes

The Benefits of Rail Transit Building and maintaining mass transit can be very expensive Cities that have rail service as a major component of their transportation systems had 36% fewer per capita traffic deaths each year, and residents drove 21% fewer miles They are also cheaper than bus-only systems Systems with only moderate rail systems did not find the same benefits

Urban Sustainability This idea seeks ways to increase the good that comes from urban centers and minimize the bad A city that imports all its resources and exports all its wastes is not sustainable Many cities around the country are trying to become more sustainable

Case Studies: Cities New York: green initiatives Mexico City: huge population growth has led to overcrowding and environmental problems Curitiba, Brazil: great mass transit and environmental planning Los Angeles or Las Vegas: urban sprawl Rizhao, China: mostly solar powered city