Urbanization Sustainable Cities

Definitions Urban (metropolitan) area = town plus its suburbs – City = large number of people with a variety of professions who depend on resources from the outside of city boundary 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

Urbanization & Urban growth Urban growth due to: – Births & Immigration Trends of urban growth: – Increase of 2% to 45% of people in urban areas since 1950 – By 2050 about 66% of the world’s people will be living in urban areas.

Urbanization & Urban growth The number of large cities is mushrooming – Today, more than 400 cities have over 1 mil. or more people. – 18 megacities with over 10 mil. People i.e.Tokyo (26 mil), Mexico City (18 mil), New York (17 mil). – 4 Hypercities (more than 20 million people)- Mumbai(India), Lagos(Nigeria), Dakha(Bangladesh) Sao Paulo(Brazil) – 2009 :38% of the people live in cities. – Many of these cities are already short on water, have waste & pollution problems.

Urbanization & Urban Growth Urban growth is slower in developed countries Poverty is becoming increasingly urbanized – slums, squatter settlements and shantytowns – 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

United States Urbanization = 5%-79% Migration from rural areas Migration to developed rural areas Large central cities to suburbs North east to South and West Urban sprawl, growth of low-density development on the edge of cities.

75% of the US population live in urban areas occupying 3% of the country’s land area

Urban sprawl: growth of low density housing availability of cheap land government loans for new single family homes government and state funding of highways low cost gasoline tax laws encourage home ownership multiple political jurisdictions which do not work together to control urban growth

Major Urban Problems in U.S. Deteriorating services Aging infrastructures Budget crunches from lost tax revenues as businesses and affluent people leave Rising poverty with violence, drugs, decay Urban sprawl - growth of low-density development on edges of cities and towns

Advantages of Urbanization – recycling more economically feasible – decreased birth rates reduces environmental pressures – per capita expenditures on environmental protection high in urban areas – population concentration impacts biodiversity less

Disadvantages of Urbanization Destruction of plant life - what is $ value? Cities produce little of own food Urban heat island effect --> “dust dome” Huge ecological footprint Water supply and flooding problems High pollution exposure Noise pollution

The enormous amount of heat generated creates an urban heat island Additional heat changes climate of surrounding area

Impacts of Urban Sprawl Land and Biodiversity Loss of cropland Loss of forests & grasslands Loss of wetlands Loss & fragmentation of wildlife habitats Increased wildlife road kill Increased soil erosion Human Health and Aesthetics Contaminated drinking water & air Noise pollution Sky illumination at night Traffic congestion Water 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

Impacts of Urban Sprawl Energy, Air, and Climate Increased energy use and waste Increased air pollution Increased greenhouse gas Emissions Enhanced global warming Warmer microclimate (heat island effect) Economic Effects Higher taxes Decline of downtown business districts Increased unemployment in central city Loss of tax base in central city

Transportation and Urban Development Determines where people live, where they go to work and buy stuff, how much land is paved and exposure to air pollution Cities grow up if they can’t grow out; more prone to use mass transit Urban sprawl due to cheap gas and land and highways; dispersed car-centered cities use 10x more energy

Pros and Cons of Mass transit 3% mass transit use in U.S. to 47% in Japan 20% gasoline tax revenues to mass transit Rapid rail, suburban trains and trolley - efficient at high population density High speed rail lines – replace planes, buses and private cars; but require large government subsidies Bus systems more flexible than rail systems

Smart growth tools for cities Regulations Zoning Planning Protection Taxes Tax Breaks (tax incentives) Revitalization

BIG PICTURE Cities are getting larger – both in area and density! Cities use a lot of resources! Urban areas have unique problems: pollution, lack of space, water & sanitation issues, etc… Urban areas can be sustainable with planning. Urban sprawl is a major issue that needs to be addressed!