Environmental Science 112FALL SEMESTER 2018INSTRUCTOR: DR. Adrienne [email protected] 18Our Urbanizing World● As of 2007, a majority of the world’s population lives in urban areas○ The shift of population into towns and cities is called urbanization● Urbanization began when increased agricultural production and accelerated during the industrial revolutionIndustrialization has driven urbanization● Developed countries have slower rates of urbanization due to higher rates of peopleliving in suburbs, the smaller communities that ring cities● Urbanization is faster in developing countries, particularly those facing war and ecological degradationEnvironmental factors influence the location of urban areas● Most urban areas are suited near a major river, a sea coast, railroad, or highway - some corridor for trade that has driven economic growth● Dallas-Fort Worth area prospers from oil-fueled transportation through interstate highways and in international airport○ This area, like other western and southern U.S. metropolitan areas, has experienced rapid growthPeople have moved to suburbs● In the 19th and 20th centuries, economic activity forced many people to remain in cities1○ By the mid-20th century, people began moving into the suburbs○ This led to a rapid decrease in population and economic declines within cities● Increasing read networks and the use of cars have spread human impact across the landscape, creating sprawlSprawl● Sprawl is the spread of low-density urban, suburban, or exurban development out from an urban center● Sprawl results from large development that places homes on spacious lots spread out over large areas, far from urban centerSprawl has several causes● There are two components that contribute to sprawl:○ Human population growth○ Per capita land consumption● Economists and politicians have traditionally encouraged sprawl, thinking that growth is always good.○ Many are beginning to feel the negative effects of sprawlWhat is wrong with sprawl?● Sprawl constrains transportation options, essentially forcing people to own a vehicleand more time in it because commuting distances● Pollution is increased by sprawl due to the use of vehicles.2citysuburbanexurban○ Cars directly release carbon dioxide, nitrogen, and sulfur-containing pollutants○ Paved areas create runoff that may contain salt or motor oil● Sprawl promotes physical inactivity, as driving takes the place of walking in daily errands● As more land is developed, less is left as forests, fields, farmland, or ranchland● Funds that are needed for maintaining downtown centers are spent on extending the road, sewer, and water systems for outlying areas, and providing other amenitiesCreating livable cities● City panning, also known as urban planning, provides advice and solutions regarding development options, transportation needs, public parks, and other matters○ Washington D.C.○ The city was built according to Charles Pierre’s plan, and a 1901 commission added efforts to beautify the city and restrict the height of buildings○ Regional planners do similar work, but across larger geographic areas that may cover more than on municipalityZoning is a key tool for planning● Zoning is the practice of classifying different areas from different types of development and land use○ This helps to preserve the tranquility of residential areas and concentrate industrial areasUrban Growth Boundaries are now widely used● Planners in Oregon created Urban growth boundaries by drawing lines on a map to designate high-density urban areas from low density rural ones○ UGB’s help to revitalize downtowns, protect farms, orchards, and forests, and3save money by restricting money spent on sprawl● Housing has also become much less affordable, with middle-income people being forced out of their traditional neighborhoods due to costs○ This transformation of a neighborhood to wealthier people is called gentrification“Smart Growth” and “New Urbanism” aim to counter sprawl● Smart Growth rejuvenates the older existing communities● Table 18.1● A related approach is new urbanism, which designs neighborhoods on a walkable scale with homes, businesses, schools, and other amenities all nearby● New-Urbanism neighborhoods are arranged around….Transit options help cities● A key component to proving urban life is to give residents alternative transportationoptions, such a bicycling○ This includes special nike lanes, public bike paths, etc● TRansportation options include mass transit systems: public buses, trains, subways, or light rail that can move large numbers of passengers while occupying less space than road networks■ Mass transit is cheaper and less polluting than vehicle pollution● The United STates lags behind most nations in mass transit○ For example: Japan, China, and many European nations have developed high-speed “bullet” trains, while the united States chose to invest in road networks for cars and trucksUrban Residents need park lands● City dwellers often desire an escape from the noise and stress of human life4Before the Flood notes●