Chapter 18. The Urban Environment: Creating Sustainable Cities. Lecture Presentations prepared by Reggie Cobb Nash Community College

Transcription

1 Chapter 18 The Urban Environment: Creating Sustainable Cities Lecture Presentations prepared by Reggie Cobb Nash Community College

2 This lecture will help you understand: The scale of urbanization Urban and suburban sprawl Planning and land use strategies Transportation, urban parks, green buildings Smart growth Impacts and advantages of urban centers Urban ecology, green building, sustainable cities

3 Central Case Study: Managing Growth in Portland, Oregon Sprawling development can ruin communities Urban growth boundaries (UGBs) separate urban from rural areas UGBs are a key to quality of life, but critics say it s elitist Urban reserves will allow development Rural reserves will preserve farms and forests

4 Our urbanizing world Urbanization The movement of people from rural to urban (towns and cities) areas Society s greatest change since it became sedentary People need a safe, clean, healthy urban environment Urban systems must be sustainable Urban populations are growing rapidly The human population is growing overall More people are moving to urban areas

5 Industrialization has driven urbanization Industrialization reduced the need for farmers Technology boosted agricultural production Urban populations will rise 59% by 2050 In developed nations, urbanization has slowed People already live in cities and suburbs (smaller communities that ring cities) Developing nations are urbanizing rapidly as people search for jobs or escape from ecological damage

6 Environmental factors influence the location of urban areas Climate, topography, and waterways influence whether a city succeeds Many well-located cities are linchpins in trading networks Funnel in resources from agricultural regions Ship products to other areas

7 Environmental factors influence the location of urban areas (cont d) Cities can thrive in resource-poor areas Cheap fossil fuels and powerful technologies (Dallas) Water is brought in from distant areas (e.g., Las Vegas) Cities in the southern and western U.S. have grown People (retirees) want warmer weather, more space Phoenix grew 97% between 1990 and 2009 By the mid-1900s, immigration and trade had increased urbanization Crowding, poverty, and crime also increased

8 People moved to suburbs Affluent people moved to suburbs for several reasons More space Economic opportunities Cheaper real estate Less crime Better schools Inner cities declined

9 What enabled people to move to suburbs? The exodus to the suburbs was enabled by: Automobiles, more roads, and abundant, cheap oil Business imported and exported resources, goods, waste The U.S. government developed interstate highways Suburbs delivered what people wanted, but Natural areas disappeared, cars are mandatory, traffic jams have increased Cities and towns are merging into each other

10 Sprawl Sprawl The spread of low-density urban or suburban development outward from an urban center Each person takes up more space than in cities The physical spread exceeds population growth Between 1986 and 2013, population and developed areas in Las Vegas both tripled

11 Sprawl has several causes Two major components of sprawl: Population growth Per capita land consumption: more people want more space and privacy Better highways, cheap gas, and telecommunication foster movement away from city centers Economists, politicians, and city boosters think growth is always good

12 What is wrong with sprawl? Transportation People are forced to drive cars Pressure to own cars and drive greater distances Increases dependence on nonrenewable petroleum Pollution Carbon dioxide, air pollutants, smog, acid precipitation Motor oil and road salt from roads and parking lots Health Sprawl promotes physical inactivity because driving cars replaces walking Increases obesity and high blood pressure

13 What else is wrong with sprawl? Land use Less forest, fields, farmland, or ranchland Loss of resources, recreation, beauty, wildlife habitat, air and water purification, other ecosystem services Economics Sprawl drains tax dollars from communities Roads, water and sewer systems, electricity, police and fire services, schools, etc., go to new areas Taxpayers, not developers, subsidize improvements

14 Weighing the Issues Sprawl Near You Is there sprawl in the area where you live? Does it bother you, or not? Has development in your area had any of the impacts previously described? Do you think your city or town should encourage outward growth? Why or why not?

15 Planning helps create livable urban areas City (urban) planning Designing cities to maximize their efficiency, functionality, and beauty Planners advise policymakers on development options, transportation needs, public parks, etc. Washington, D.C., is the first U.S. example of planning Urban planners wanted to beautify and impose order on fast-growing, unruly cities The 1912 Greater Portland Plan recommended rebuilding the harbor, new construction, wide roads

16 Washington, D.C., was a planned city Pierre Charles L Enfant s 1791 plan called for diagonal avenues, majestic monuments, and a spacious, stately feeling

17 Planning helps create livable urban areas (cont d) Regional planning Deals with same issues as city planning, but with broader geographic scales Must coordinate with multiple municipal governments Some areas have institutionalized planning in formal government bodies Portland s Metro apportioned land into urban and rural reserves Homeowners, farmers, developers, and governments will know what future land uses will be

18 Zoning is a key tool for planning Zoning Classifies areas for different types of development and land use A powerful way to guide what gets built where Zoning involves government restrictions on private land Opponents say that its restrictions violate individual freedoms Proponents say government can set limits for the good of the community After seeing undesirable development, Oregonians voted for land restrictions

19 Urban growth boundaries (UGBs) Limit sprawl Keep growth in existing urbanized areas Revitalize downtowns Protect farms, orchards, ranches, forests Ensure urban dwellers some access to open space May reduce infrastructure costs But they do increase housing prices within the UGB Other states, regions, and cities have adopted UGBs Boulder, Colorado; many California areas Unrelenting population growth still causes sprawl

20 Smart growth and new urbanism aim to counter sprawl Smart growth Rejuvenates existing developed areas Building up, not out Favors multistory shop-houses and high-rises A strong sense of place and collaboration New urbanism Designs walkable neighborhoods Homes, businesses, and schools are close together Functional neighborhoods in which a family can meet most needs without using a car New developments have greenspaces, mixed architecture, creative street layouts

21 Smart growth and new urbanism aim to counter sprawl (cont d) Recommendations for smart growth

22 Transit options help cities Traffic jams cause air pollution, stress, and lost time Cost the U.S. $74 billion/year Bicycle transportation 6% of Portland, OR, commuters ride their bicycles to work (national average is 0.5%) 400 miles of bike lanes 5000 public bike racks

23 Transit options help cities (cont d) Key in improving quality of urban life: mass transit Buses, trains, subways Light rail: smaller systems powered by electricity Cheaper, more energy- efficient, cleaner, less traffic

24 Transit options help cities (cont d) The most-used U.S. train systems are in large cities New York s subways, the T in Boston Carry 25% of each city s daily commuters Portland s buses carry 66 million riders per year Each bus keeps 250 cars off the road each day Most nations have extensive mass transit The U.S. lags behind in mass transit systems Why is U.S. mass transit behind? Low population density and cheap fuel

25 Urban residents need parklands City dwellers want to escape the noise, commotion, and stress of urban life Natural lands, public parks, and open space provide greenery, beauty, freedom, and recreation They also regulate natural processes (e.g., filtering pollutants, climate, wildlife habitat) Even small spaces can be important Playgrounds or community gardens Greenways along rivers, streams, or canals Protect water quality, boost property values, are corridors for wildlife

26 Urban residents need parklands (cont d) America s city parks arose at the end of the 19th century Made dirty, crowded cities more livable Lawns, groves, and curved pathways originated with European ideals Portland s Forest Park is the largest U.S. city park New York s High Line Park

27 Green buildings bring benefits Buildings use 40% of the energy and 70% of the electricity we consume Green buildings Use technologies and approaches to minimize their ecological footprint Built from sustainable materials, limit energy and water use, control their pollution, and recycle wastes Leadership in Energy and Environmental Design (LEED) certification program New or existing buildings can be granted silver, gold, or platinum status

28 Example of a green building Green buildings are becoming popular at universities

29 Urban sustainability Making cities more livable makes them more sustainable A sustainable city functions over the long term Provides generations with a good quality of life Minimizes impacts on natural systems and resources Urban centers exert positive and negative environmental impacts

30 Urban centers bring a mix of environmental effects Cities are resource sinks Need lots of land elsewhere to supply resources Efficiency Cities allow efficient delivery of goods and services Electricity, schools Water and sewer systems Waste disposal Transportation

31 Cities preserve land but export pollution Because people are packed densely in cities, more land outside cities is left undeveloped Without cities, we would have much less room for agriculture, wilderness, biodiversity, or privacy Cities export wastes through pollution and trade They transfer the costs of activities to other regions Residents are exposed to chemicals, smog, and noise and light pollution The poor bear the brunt of pollution because they don t have the financial means to move to cleaner areas

32 Cities are polluted but innovative Urban heat island effect Cities are hotter than surrounding areas Cities promote a flourishing cultural life Spark innovation and creativity, promoting education and scientific research Are engines of technological and artistic inventiveness that can solve societal problems

33 Frequently Asked Question Aren t cities bad for the environment?

34 Urban ecology helps cities toward sustainability Cities must replace the linear, one-way metabolism of importing resources and exporting wastes Urban ecology: cities should mimic ecosystems Use resources efficiently and recycle Develop environmentally friendly technologies Account fully for external costs Offer tax incentives for sustainable practices Use locally produced resources Use organic waste and wastewater to fertilize soil Encourage urban agriculture

35 The Science Behind the Story Baltimore and Phoenix Showcase Urban Ecology The U.S. National Science Foundation selected Baltimore and Phoenix as research sites for its Long Term Ecological Research program In Baltimore, scientists found that urban and suburban watersheds have far more nitrate pollution than natural forests

36 The Science Behind the Story (cont d) Baltimore and Phoenix Showcase Urban Ecology Baltimore also recorded negative impacts of applying salt to icy roads in winter Streams are 100 times saltier, even in the summer Salt kills organisms, degrades habitat and water quality Baltimore is now improving water quality by upgrading its sewer system Researchers found that proximity to a park increases a home s property values Unless crime is pervasive, in which case property values decrease

37 Sustainability is happening, but slowly Urban sustainability is occurring in many places Recycling, urban agriculture, mass transit, job training PlaNYC: New York City is trying to become the first environmentally sustainable 21st-century city It will have 1 million more people by 2030 It has already increased energy efficiency, planted trees, improved playgrounds, installed bike lanes, etc. Success stories tell us we can make cities sustainable

38 Conclusion As half the human population has moved to urban lifestyles, our environmental impact has changed Impacts are less direct but more far-reaching Urban sustainability makes cities better places to live Planning and zoning involve long-term visions Smart growth and new urbanism reduce energy use Mass transit reduces energy use and emissions Parks provide health and ecosystem services Green buildings provide multiple benefits