Urbanization

• Creation and growth of urban areas or cities and their surrounding developed land

• Urban growth

  • The rate of increase of urban populations

  • Urban areas grow in two ways

    • Natural increase

    • Immigration

• Rural people are pulled to urban areas in search of jobs, housing, educational opportunities, health care, entertainment, and freedom from religious, racial, and political conflicts

• Main advantages

  • Access to education

  • Sanitation

  • Access to health care

  • More jobs

  • Better transportation

• Main disadvantages

  • Worse air quality

  • High population density

    • Increase spread of communicable disease

  • Noise pollution

    • High levels of stress

  • High crime rate

Advantages of Urbanization

• Cities

  • Centers of economic development, innovation, education, industry, commerce, transportation, and jobs

    • Better access to medical care, family planning, education, and social services

• Recycling is more economically feasible because concentrations of recyclable materials

• Concentrating people in cities helps preserve biodiversity by reducing the stress of wildlife habitats

• Central cities can save energy if residents rely more on energy-efficient mass transportation

Disadvantages of Urbanization

• Huge ecological footprints

• Lack of vegetation

• Water problems

• Concentrate air pollution

• Health issues

• Excessive noise

• Create different climates

• Light pollution

Phases of Urbanization

• People migrated from rural ares to large central cities

• Many people migrated from large central cities to suburbs and smaller cities

• Some people fled both cities and suburbs and migrated to developed rural areas

Urban Sprawl

• The growth of low-density development on the edges of cities and towns

• Major factors that promoted urban sprawl in the U.S.

  • Ample land was available for most cities to spread outward

  • Federal government loan guarantees for new single family homes for WWII veterans stimulated the development of suburbs starting around 1950

  • Low cost gasoline and federal and state funding of highways encourages automobile use and the development of outlying tracts of land

  • Technology has made possible to work from home

  • Goof suburban school districts

  • More space to raise children

  • Higher quality of life

Environmental Problems

• Building homes in preserved areas causes habitat destruction/fragmentation

• Problems related to the high usage of fossil fuels, since more people drive to work and other places

Ecological Footprints

• Urban populations only occupy around 2% of the earth’s land are, but they consume 75% of its resources and produce 75% of all carbon dioxide emissions from human activities

• Most of the world’s cities are not self-sustaining systems

• Large areas of land must be destroyed and degrade to provide for the urban people, which results in the lowering of biodiversity

• Most urban dwellers live in an artificial environment that isolates themselves from natural areas that contain biodiversity

Lack of Vegetation

• Most trees, shrubs, and other plants are destroyed in urban areas in order to make way for development

• Vegetation is important because it absorbs air pollutants, gives off oxygen, cools the air through transpiration, provides shade, muffles noise, and provides habitats

Water Pollution

• As water demands increase, expensive reservoirs must be built, and deeper wells must be drilled

  • Can deprive rural and wild ares of surface water and deplete groundwater

• Covering land with asphalt and concrete causes precipitation to runoff quickly and overload storm drains, causing flooding

• Global warming is causing urban dwellers in arid areas to have a shortage of water

Pollution

• High population densities and high resource consumption causes cities to produce most of the world’s air pollution, water pollution, and waste

• Pollution is produces in a small area and cannot be dispersed and diluted as easily as pollution in rural areas

• Most of the CO2 from human related sources are due to urban areas

• Nitrogen nutrients in runoff can disrupt the nitrogen cycle

Excessive Noise

• Urban dwellers are subject 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

• Too much noise can kill someone and cause permanent hearing damage

Light Pollution

• The artificial light created

• Affects some plant and animal species

  • Migrating birds

    • Lured off course by the lights of a high rise building

    • Fatally collide with the buildings

Heat Island Effect

• Cities are generally warmer than the suburbs and rural areas

• Causes

  • The enormous amount of heat created by cars, factories, air conditioners, and heat-absorbing dark roofs and streets in cities creates an urban heat island, surrounded by cooler rural and suburban areas

• Consequences of the heat island effect

  • Increases the formation of photochemical smog

  • Increases dependence on air conditioning for cooling

  • Increases energy consumption

Transportation

• Motor vehicles have many harmful effects on people and the environment

  • Automobile accidents kill approximately 1.2 million people a year and injure another 15 million

  • Kill about 50 million wild animals and family pets a year

• World’s largest source of outdoor pollution, and cause 30,000 to 60,000 premature deaths per year in the U.S.

• Fastest growing source of climate changing CO2 emissions

• Account for ⅔ of oil used in the form of gasoline in the U.S. and ⅓ of the world

• At least a third of urban land worldwide, and half in the U.S. is devoted to roads, parking lots, gasoline stations, and other automobile related uses

Reducing Automobile Use

• Charge a tax on gasoline to cover the estimated harmful cost of driving

  • Such a tax would amount to about $3.18 per liter of gasoline in the U.S.

Alternatives to Car Ownership

• Mass transit rail

  • Advantages

    • Uses less energy

    • Produces less air pollution

    • Requires less land

    • Causes fewer injuries and deaths

    • Reduces car congestion in cities

  • Disadvantages

    • Expensive

    • Commits riders to a schedule

    • Causes noise and vibration

• Bicycles

  • Advantages

    • Affordable

    • No pollution

    • Quiet

    • Require little parking space

    • Easy to maneuver in traffic

    • Require few resources

  • Disadvantages

    • Little protection in an accident

    • No protection from bad weather

    • Impractical for long trips

    • Tiring

    • Lack of secure parking

• Buses

  • Advantages

    • Can be rerouted

    • Cost less to develop and maintain

    • Can reduce car use and air pollution

  • Disadvantages

    • Can lose money due to low fares

    • Can get caught in traffic and add to pollution

    • Commits riders to a schedule

    • Noisy

• Rapid Rail

  • Advantages

    • Reduce travel by car and plane

    • Ideal for long trips

    • Energy efficient

  • Disadvantages

    • Expensive

    • Must operate along heavily used routes

    • Cause noise and vibration

Conventional Land-Use Planning

• Urban and rural areas use some form of land-use planning to determine the best present and future use of each parcel of land

  • Encourage future population growth and economic development, regardless of the environmental and social consequences

• Leads poorly controlled urban growth and sprawl

  • 90% of the revenue of local governments used to provide public services comes from property taxes levied on building/property based on economic value

• Zoning

  • Most widely used approach in which various parcels of land are designated for certain uses

    • Can be used to control growth and protect areas from some types of development

    • Disadvantages

      • Threatens/destroys environment

      • Favors high-priced housing over protecting environmentally sensitive areas and low-priced housing because of property tax revenue from high-priced developments

Smart Growth

• Limits and regulations

  • Limit building permits

  • Urban growth boundaries

  • Greenbelts around cities

  • Public review of new development

• Zoning

  • Encourage mixed use of housing and small businesses

  • Concentrate development along mass transportation routes

  • Promote high-density clutter housing developments

• Planning

  • Ecological land use planning

  • Environmental impact analysis

  • Integrated regional planning

  • State and national planning

• Protection

  • Preserve existing open space

  • Buy new open space

  • Buy development rights that prohibit certain types of development on land parcels

• Taxes

  • Tax land, not buildings

  • Tax land on value of use

• Tax breaks

  • For owners not agreeing to allow certain types of developments

  • For cleaning up and developing abandoned urban sites

• Revitalization and New Growth

  • Revitalize existing cities/towns

  • Build well-planned new towns and villages within cities