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CHAPTER 15. Population, Urbanization, and the Environment. Key Topics. 15-1 Population Dynamics 15-2 Urbanization 15-3 Environmental Issues. Population Dynamics. Population Dynamics. Demography : the scientific study of human populations
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CHAPTER 15 Population, Urbanization, and the Environment
Key Topics 15-1 Population Dynamics 15-2 Urbanization 15-3 Environmental Issues
Population Dynamics Demography: the scientific study of human populations Examines size, composition, distribution of populations Looks at changes and causes of changes in populations
Population Dynamics Population: a group of people who share a geographic territory Vary in size from a small town to the planet
Population Dynamics World’s population Grown rapidly since 1800 Reached 1 billion in 1804 6.5 billion by 2005 Expected to reach 9.4 billion by 2050
Population Dynamics Fertility: the number of babies born during a specific period in a particular society Crude birth rate: the number of live births per 1,000 population in a given year In 2011 the CBR was 20 worldwide, 36 for Africa, and 13 for the U.S.
Population Dynamics Birth rates vary within a country. In the U.S., birth rates are lower for the more affluent and those with more education.
Population Dynamics • Mortality: the number of deaths during specified period in a population • Crude death rate: the number of deaths per 1,000 people in a population in a given year • 2011 crude death rate • World 8 • U.S. 8 • Some African countries 15
Population Dynamics • Infant mortality rates: the number of deaths among infants under 1 year of age per 1,000 live births • 2011 mortality rate • U.S. 6 • South America 18 • Afghanistan 131
Population Dynamics • Life expectancy: the average number of years that people who were born at the same time will live • 2011 life expectancy • World 70 • U.S. 78 (below at least 25 other developed countries)
Population Dynamics Migration: the movement of people into or out of a specific geographic area Push factors: encourage people to leave Pull factors: attract people to new area
Population Dynamics • International migration: the movement across a national border • Emigrants move out of a country • Immigrants move into a country • Internal migration: movement within a country
Population Dynamics—Application Identify the type of migration and push or pull factors. Josh’s family moved from Louisiana to Texas after Hurricane Katrina. After a beef plant closed in Iowa, a family moved to Minnesota in search of work. A family moved from Afghanistan to France to escape the war.
Population Dynamics • Sex ratio: the proportion of males to females in a group • 100—equal numbers of males and females • 95—fewer males than females • 105—fewer females than males
Population Dynamics Population pyramid: a visual representation of the age and sex structure of a population at a given point in time Allows demographers to predict future needs of a population
Population Dynamics Malthusian theory: the belief that the population is growing faster than the food supply needed to sustain it (Thomas Malthus 1798) • Population will outdistance food supply. • Population grows geometrically. • Food supply grows arithmetically.
Population Dynamics Neo-Mathusians agree that the world population is exploding beyond food supplies. Earth has become a dying planet with increasing population and pollution. Number of hungry people in the world increased to 1.02 billion in 2009.
Population Dynamics Demographic transition theory: maintains the population growth is kept in check and stabilizes as countries experience economic development. Development involves industrialization, modernization, technological advancements, and urbanization.
Population Dynamics Stages in the demographic transition: 1—Preindustrial: high birth rates and high death rates 2—Early industrialization: high birth rates and lower death rates (population growth) 3—Advanced industrialization: lower birth rates and death rates (lower growth rate) 4—Postindustrial: low birth and death rates (stability or decrease in population)
Population Dynamics Zero population growth: each woman has no more than two children resulting in a stable population. Many nations are now experiencing zero population growth.
Urbanization City: a geographic area where a large number of people live relatively permanently and make a living through nonagricultural activities Urbanization: the movement of people from rural areas to cities
Urbanization The Industrial Revolution created a surge in urbanization as people moved to cities in search of jobs and improved living conditions. In 2008, a majority of the world’s population lived in urban areas for the first time in history.
Urbanization Megacities: metropolitan areas with at least 10 million inhabitants Becoming more common By 2025, there will be 37 megacities in the world with 3 in the U.S.
Urbanization In U.S., the fastest growing counties are near metropolitan areas. Suburbanization: movement from cities to the areas surrounding them. More than 60% of Americans reside in suburbs.
Urbanization Edge cities: business centers that are within or close to suburban residential areas Exurbs: areas of new development beyond suburbs on the fringe of urbanized areas
Urbanization • Urban sprawl: the rapid, unplanned, and uncontrolled spread of urban development into neighboring regions • Loss of farmland, wildlife habitats, forests, and open recreation areas • Increased cost of purchasing and maintaining automobiles • Air and water pollution • Job sprawl
Urbanization Gentrification: the process of buying and renovating houses and stores by middle-class and affluent people in downtown urban neighborhoods Revitalizes urban areas and augments taxes Results in displacement of low-income people and small business
Urbanization Racial segregation: as suburbs expanded, low-income African Americans were left in the central cities with few housing and employment choices Decreasing but average black or Latino household lives in a poorer neighborhood Suburbs are becoming “ethnoburbs.”
Urbanization Sociological explanations of urbanization: How and why do cities change? How do the changes affect populations?
Urbanization: Functionalism Functionalists developed theories of urban ecology: the study of the relationships between people and their urban environment Theories analyzed the growth of cities into different patterns.
Urbanization: Functionalism Concentric zone: city grows outward in a series of rings Sector theory: pie-shaped wedges radiate from central business district Multi-nuclei: city contains multiple centers Peripheral: suburbs and edge cities develop through highway development
Urbanization: Conflict Conflict theory: heavily influenced new urban sociology Economic and political factors determine urban growth or decline. Urban changes are influenced by the dominant social class and powerful capitalists. Urban space is a commodity to be bought and sold.
Urbanization: Feminist Feminist scholars emphasize gender-related constraints. Developers ignored women’s changing roles. Poor women and minorities have the least access to decent housing. Safe public transportation and other public areas are limited.
Urbanization: Symbolic Interactionists Symbolic interactionistsare interested in the impact of urban life on its residents. Urbanism is a way of life characterized by tolerance of different lifestyles but superficial interaction and social isolation. Recent studies find satisfying lives for urbanites.
Urbanization—Application Identify the theoretical perspective: People create suburbs to enhance their quality of life. Financial institutions determine the shape of cities. Urbanites are more socially isolated than those in rural areas.
Environmental Issues Ecosystem: involves a physical environment and all forms of life living in relation to one another Environmental problems threaten our ecosystem.
Environmental Issues Access to clean water: More than 1 billion people do not have clean water. Over 3 million children die every year because of diarrheal diseases. Water-related diseases cause 50% of illnesses and deaths.
Environmental Issues Threats to water supply: • Pollution: • Toxins from cities, factories, and farms • The Clean Water Act (1972) and Safe Drinking Water Act (1974) are often violated with little punishment.
Environmental Issues Threats to water supply: Privatization: transferring assets or operations of public water systems into private hands Bottled water depletes local water sources and creates plastic water garbage.
Environmental Issues Threats to the water supply: • Mismanagement • Most water-related problems are due to human mismanagement, corruption, and bureaucratic bungling. • Many water and sewage pipes are old and deteriorating. • Agricultural waste includes production of water-hungry crops in arid areas.
Environmental Issues The most common sources of air pollution are: Fossil fuels Manufacturing Winds blowing contaminants to other areas Government policies including lack of enforcement of pollution law
Environmental Issues Global warming: increased temperature of the earth’s atmosphere The greenhouse effect: heating of the earth’s temperature due to atmospheric gases
Environmental Issues Climate change: change of overall temperatures and water conditions over time Increases in ocean acidity Loss of livelihoods Coastal erosion and loss of homes Floods and droughts