Key Concepts • Distribution of urban & rural populations • Factors determining urban development • Resource & environmental problems in urban areas • Effects of transportation systems on urban growth • Planning & controlling urban growth • Making cities more sustainable & desirable
Urbanization and Urban Growth Urban (metropolitan) area = town plus its suburbs Rural area = an area with a population less than 2,500 people Village = group of rural households liked by custom, culture, family ties. Historical utilization of natural resources City = large number of people with a variety of professions who depend on resources from the outside of city boundary Urban growth: natural increase = births > deaths & immigration mostly from rural areas “pull factors” i.e. jobs, quality of live; & “push factors” i.e. poverty.
Patterns of Urban Growth Increasing proportion of population: By 2050 about 66% of the world’s people will be living in urban areas. Great increase in large cities: Today, more than 400 cities have over 1 mil. or more people. 19 megacities with over 10 mil. people i.e.Tokyo (28 mil), Mexico City (18 mil), New York (17 mil).
Patterns of Urban Growth Increasing rapidly in developing counties: 38% of the people in live in cities. But by 2025 it will be 54%. Many of these cities are already short on water, have waste & pollution problems. Urban growth slower in developed countries: 75% of the people live in cities. But by 2025 it will be 82%. Poverty in urban areas increasing: At least 1 billion people live in crowed slums of inner cities. No access to water, sewer, electricity, education etc. 100 mil people are homeless & sleep on the streets.
Patterns of Urban Growth • Mexico City or “Makesicko City” • The world second largest city with 18 mil people. • Hence: • - server air pollution (over 4 mil. cars) • high unemployment rate, close to 50% • high crime rate • over one-third (= 6 mil.) of its residents live in slums • (barrios) without running water, sewer or electricity • high infection rates i.e. salmonella, hepatitis - “Children of Mexico City”
General Patterns of Urbanization in the US Migration to large central cities Migration from cities to suburbs Migration from north & east to south & west Urban sprawl, growth of low-density development on the edge of cities. Encouraged by: - availability of cheap land, (forests, agriculture fields etc.). - government loans guarantees for new single-family homes - government & state funding of highways - low-cost gasoline encourage car use - low interest mortgage
Major Urban Regions in the US 75% of the US population live in urban areas occupying 3% of the country’s land area
Impacts of Urban Sprawl Water Land and Biodiversity Human Health and Aesthetics Increased runoff Increased surface water & groundwater pollution Increased use of surface water & groundwater Decreased storage of Surface water & groundwater Increased flooding Decreased natural Sewage treatment Loss of cropland Loss of forests & grasslands Contaminated drinking water & air Noise pollution Sky illumination at night Traffic congestion Loss of wetlands Loss & fragmentation of wildlife habitats Increased wildlife roadkill Increased soil erosion
Impacts of Urban Sprawl Economic Effects Higher taxes Decline of downtown business districts Increased unemployment in central city Loss of tax base in central city Energy, Air, and Climate Increased energy use and waste Increased air pollution Increased greenhouse gas emissions Enhanced global warming Warmer microclimate (heat island effect)
Urban Sprawl: Atlanta, GA becoming a megalopolis kilometers kilometers 0 32 1980 2000 Urban Sprawl 0 32 Rural: Fewer than 320 people per square mile, or 1 person per 2 acres on average 0 20 0 20 miles miles Pickens Pickens Cherokee Cherokee Bartow Bartow Forsyth Forsyth Suburban: Between 320 and 3,200 people per square mile, or up to 5 people per acre on average Gwinnett Cobb Barrow Barrow Cobb Pickens Gwinnett Pickens Walton Walton Urban: 3,200 people or more per square mile Fulton Fulton Newton Carroll Newton Carroll Fayette Henry Henry Spalding Coweta Fayette Fayette Coweta 10-county metropolitan area Spalding
General Overview:Urban Resource & Environmental Problems Urban dweller occupy 4% of the earth’s land area, they consume 75% of the earth’s resources Air & water pollution; (industrial & photochemical smog); waste management (landfills, groundwater contamination). Reduction in vegetation, & wildlife, introduction of exotic & feral domestic species.
General Overview:Urban Resource & Environmental Problems Importation of food, energy, & materials, hence not a self-sustaining system. Climate impacts: urban heat island Noise pollution Higher crime rates Impacts on surrounding rural areas High population density promotes the spread of infectious diseases.
Urban Areas: Inputs and Outputs -no self-sustaining systems- Inputs Outputs Energy Solid wastes Waste heat Food Air pollutants Water Water pollutants Raw materials Greenhouse gases Manufactured goods Manufactured goods Noise Money Wealth Information Ideas
Urban Heat Island 92° 33° Late afternoon temperature (°C) Late afternoon temperature (°F) 29° 85° Rural Suburban residential Commercial Downtown Urban residential Park Suburban residential Rural farmland Vegetation “service”: absorb air pollutions, give off oxygen, cool the air as water transpires, provide shade hence less AC required, reduce soil erosion, muffles noise, provides wildlife habitat and gives us an island of peace.
Urban Water, Pollution & Noise Problems As cities grow & their water demand increases, expensive reservoirs & canals must be built and deeper wells drilled. This leads to depletion of surface and ground water & water stress for wildlife, i.e. Colorado River. Between 50 to 70% of the water is lost or wasted. Because many cities are build in floodplain flood events are more frequent. Ground sealing asphalt & concrete enhances run offs & quick overload of canalized rivers or drains.
Urban Water, Pollution & Noise Problems Most of the largest cities are in coastal areas, hence a raise in sea level brings additional problems. Higher air pollution in cities causes respiratory diseases, asthma etc. Increased noise levels cause stress, including: high blood pressure, ulcer, insomnia, increased aggression, hampers concentrations & work efficiency, causes accidents, hearing problems.
Transportation & Urban Development Drive alone 80% Other 4% Public transit 5% Car pool 11% Transportation & land-use decisions are liked together & determine: - where people live - the distance to work and to go shopping - how much land is paved over - amount of air pollution & exposure Individual transit cars, scooter, bikes etc. Mass transit buses & trains
Urban Land-Use Planning and Control Land-use planning based on the philosophy that population growth & economic development should be encouraged, while neglecting the environment. This is directly linked to property taxes which is used for schools, police, fire department, water & sewer systems. Therefore, local government will encourage economic growth & developments. Reelection terms lead to short term (thinking) projects & problem solving. Ecological land-use planning urge communities to use comprehensive, regional ecological land-use to anticipate a region’s present & future needs & problems.
Urban Land-Use Planning and Control Ecological land-use planning: 1. Make an environment & social inventory: Geologicalfactors (soil type, water availability). Ecological factors (wildlife habitats, pollutions). Economic factors (housing, transportation, industry). Health & social factors (disease, crime & poverty). 2. Identify & prioritize goals: Encourage or discourage economic development Protect prime habitats, forest, & wetlands. Reduce soil erosion. 3. Develop data base (individual layers) by using new mapping technology. 4. Develop & implement a master plan.
Solutions: Making Urban Areas More Livable & Sustainable New cities and towns i.e. Gainesville, learn from past mistakes. Cities could be more sustainable, energy efficient & enjoyable. Ecocity (green city) emphasis is placed onpreventing pollution & reduce waste, public transportation, bike paths, using energy & matter resource, efficient, recycling & reuse, composting to help create soil, using solar & other locally available renewable resources, encouraging biodiversity by providing habitats such as planning native trees, ponds in the backyard, This city is People and Nature-oriented & Not car-oriented
Environmental Worldviews in Industrial Societies Environmental worldviews Individual-centered Earth-centered Human-centered Life-centered Ecosystem-centered
Environmental Worldviews Environmental Worldviews Atomistic (individual-centered) Holistic (earth-centered or ecocentric) Anthropocentric (human-centered) Biocentric (life-centered) Biosphere-centered Individual- centered Ecosystem-centered Species-centered
Values Instrumental (utilitarian) value: Something has a value because it is useful to us. Hence, certain things are without a value Anthropocentric worldview Intrinsic (inherent) value: Something has a value because it exist, independently of their use to humans. Biocentric worldview
Planetary Management Worldview A human-centered environmental worldview where nature has only instrumental values -Humans are the most important species -There is always more -All economic growth is good -Human success depends on how humans manage things
Variations on Planetary Management No-problem school: there are no environmental or resource problems that cannot be solved by our creativity. Free-market school: a global free-market with minimal government interference as the problem solver. Stewardship school: we have an ethical responsibility to be caring and responsible stewards of the earth.
Life-Centered Environmental Worldviews Humans should not cause the premature extinction of species Actively protect species endangered by human activities Some believe all species have a right to survive
Earth-Centered Environmental Worldviews Ecocentric worldview: We are part of, not apart from the community of life & the ecological processes that sustain all life. Emphasis on preserving functioning ecosystems Humans are part of ecological processes
Environmental Wisdom Worldview Humans are part of nature. There is not always more, (resources limitation) Some types of technology and economic growth are good, but discourage harmful ones. Human success depends on learning how earth systems work and applying what we learn. Deep ecology: recognize both the intrinsic & instrumental values of nature.
Solutions: Living Sustainably Biosphere and ecosystem responsibilities Species responsibilities Cultural responsibilities Individual responsibilities
Environmental Education Where do things I consume come from? What do I know about the place where I live? How am I connected to the Earth and other living things? What are my purpose and responsibility as a human being?