Human Population and Urbanization

• Human Population Growth


  Shows certain trends
• For most of history, the human population grew slowly
• Why did the human population grow slowly for most of history?

  • Early and modern agriculture allowed us to feed more people
  • Technologies helped us expand into almost all of the planet's climate zones and habitats
  • Death rates dropped sharply because of improved sanitation and health care and the development of antibiotics and vaccines to help control infectious diseases
• In 1960, the human population has grown rapidly
• Trends in human population growth

  • The rate of population growth has slowed after 1960
  • The world's population is still growing at a rate of about 1.2%
  • Human population growth is unevenly distributed
  • People have moved in large numbers from rural areas to urban areas. About 52% of world's people now live in urban areas and this trend is increasing
• Advances in food production and health care have staved off widespread population declines, but there is extensive and growing evidence that we are depleting and degrading much of the earth's irreplaceable natural capital and that we are approaching or exceeding various planetary boundaries
• Population change

  (Births + Immigration) - (Deaths + Emigration)
• Total fertility rate (TFR)


  The average number of children born to the women in a population during their reproductive years
• Factors affecting birth and fertility rates

  • Importance of children as a part of the labor force
  • Cost of raising and educating children
  • The availability of, or lack of, private and public pension systems
  • Urbanization
  • Educational and employment opportunities available for women
  • Average age at marriage
  • Availability of legal abortions
  • Religious beliefs, traditions, and cultural norms
• In India, most poor couples believe they need several children to work and care for them in their old age, and the strong cultural preference in India for male children means that some couples keep having children until they produce one or more boys
• India already faces serious soil erosion, overgrazing, water pollution, and air pollution problems
• In the 1960s, China's large population was growing so rapidly that there was a serious threat of mass starvation, so the government took measures that eventually led to the establishment of the world's most extensive, intrusive, and strict family planning and birth control program
• The Chinese government provides contraceptives, sterilizations, and abortions for married couples, and married couples pledging to have no more than one child receive a number of benefits, including better housing, more food, free health care, salary bonuses, and preferential job opportunities for their child. Couples who break their pledge lose such benefits
• Poverty


  The single most important factor affecting life expectancy (the average number of years a person can be expected to live)
• Infant mortality rate

  The number of babies out of every 1,000 born who die before their first birthday. A high infant mortality rate usually indicates insufficient food (undernutrition), poor nutrition (malnutrition), and a high incidence of infectious disease
• Migration


  The movement of people into (immigration) and out of (emigration) specific geographic areas
• Most people migrate to seek jobs and economic improvement, religious persecution, ethnic conflicts, political oppression, or war. There are also environmental refugees—people who have to leave their homes and sometimes their countries because of water or food shortages, soil erosion, or some other form of environmental degradation or depletion
• Age structure


  An important factor determining whether the population of a country increases or decreases
• Age categories in a population age-structure diagram

  • Prereproductive (ages 0–14)
  • Reproductive (ages 15–44)
  • Postreproductive (ages 45 and older)
• Crude Birth Rate

  The number of live births per 1,000 population in a given year
• Crude Death Rate

  The number of deaths per 1,000 population in a given year
• Rate of Natural Increase (RNI)

  Crude Birth Rate - Crude Death Rate
• The chart shows selected population data for two different countries, A and B
• To calculate the rates of natural increase (due to births and deaths, not counting immigration) for populations of country A and country B

  1. Calculate the RNI for each country using the formula RNI = CBR - CDR

  2. Based on the RNI and the data in the table, determine if each country is more-developed or less-developed and explain the reasons
• We can slow human population growth by reducing poverty through economic development, elevating the status of women, and encouraging family planning
• Demographic transition


  A theory that describes the transition of high birth and death rates to low birth and death rates as a country develops from a pre-industrial to an industrialized economic system
• Some analysts believe that most of the world's less-developed countries will make a demographic transition over the next few decades, primarily because newer technologies will help them to develop economically and to reduce poverty by raising their per capita incomes
• Other analysts fear that rapid population growth, extreme poverty, and increasing environmental degradation and resource depletion could leave some low-income, less developed countries stuck in stage 2 of the demographic transition
• Women tend to have fewer children if they are educated, have the ability to control their own fertility, earn an income of their own, and live in societies that do not suppress their rights
• Family planning


  The provision of education and clinical services that can help couples to choose how many children to have and when to have them
• Family planning enables women to limit the size of their families if they wish to do so, and to plan their pregnancies
• Urban trends

  • The percentage of the global population that lives in urban areas has grown sharply and this trend is projected to continue
  • The numbers and sizes of urban areas are mushrooming
  • Poverty is becoming increasingly urbanized, mostly in less-developed countries
• Cities are centers of economic development, innovation, education, technological advances, social and cultural diversity, and job markets
• Urban residents in many parts of the world tend to live longer than do rural residents and to have lower infant mortality and fertility rates. They typically also have better access to medical care, family planning, education, and social services than do their rural counterparts
• Concentrating people in cities helps to preserve biodiversity by reducing the stress on wildlife habitats
• Central-city dwellers tend to drive less and rely more on mass transportation, car-pooling, walking, and bicycling
• Undesirable impacts of urban sprawl

  • High input of food, water, and other resources
  • Resulting high waste output
• Urban environmental problems

  • Most cities lack vegetation
  • Many cities have water problems
  • Cities tend to concentrate pollution and health problems
  • Cities have excessive noise
  • Cities affect local climates
• Life is a desperate struggle for the urban poor in less-developed countries
• Motor vehicles


  Provide mobility and offer a convenient and comfortable way to get from one place to another