En Sci Finals

• World population = 6.4 billion (6,400,000) in 2004

  
• World population doubled since 1963 = 3.2 billion
• In 2050 world population could be 7.2 – 10.6 billion
• Largest increase expected in developing countries (approximately 97%)
• Decreasing in some developed countries
• Rate actually decreased between 1963-2004, but the population has still doubled from 3.2 –6.4 billion
• Rate = 80 million new people/year
• Number of large cities growing. World's urban population will increase from 3.1 billion to 5 billion from 2004-2030
• Population change


  Births + Immigration - Deaths + Emigration
• Crude birth rate


  Births per 1000 people in population per year
• Crude death rate


  Deaths per 1000 people in population per year
• Total Fertility Rate (TFR)


  Number of children a woman has during her lifetime, averaged for population
• Replacement Level Fertility


  Number of children needed to replace everyone in the population
• Replacement Level Fertility varies between regions - 2.1 per woman with low infant mortality, 2.5 per woman with high infant mortality
• Zero Population Growth


  Birth rate equals death rate

  
• Sex Ratio


  Relative number of males and females in a population
• Age Distribution


  Number of individuals of each age in a population
• 30% of population <15 years = 1.9 billion more into reproductive years
• Developed Countries


  • Low infant mortality rate
  • Life expectancy 77 years
  • Total fertility rate = 2.0
  • 21% population <15 yrs. old
  • 12% population >65 yrs. old
  • Per capita GDP = $36,110

  
• Developing Countries


  • High infant mortality rate
  • Life expectancy 52 years
  • Total fertility rate = 5.7
  • 44% population <15
  • 3% population >65
  • Per capita GDP = $800
• Demography


  Study of populations and their characteristics
• Larger ecological footprint in U.S. than in developing countries
• Factors Affecting Birth Rates and Total Fertility Rates

  • Children in Labor Force
  • Cost of raising and educating children
  • Availability of pension systems
  • Urbanization
  • Education and employment for women
  • Infant mortality rate
  • Average marrying age
  • Abortion
  • Availability of birth control
• Major social factor determining family size is the role of women in society
• Early marriages foster high fertility rates
• Lack of education opportunities for women reduces their options
• When level of education increases, fertility rates fall
• The most important factor is the ability of women to control the size of their family
• Access to birth control (i.e., natural or artificial)
• By 2030, 20% of US population will be over 65 yrs. old
• Immigration accounts for 41% of population growth in the U.S.
• Demographic Transition


  As countries become industrialized, death rates, then birth rates decline
• India's population growth has been generally disappointing - 1952 = 400 million, 2004 = 1.2 billion
• Reasons for India's slow population growth: poor planning, bureaucratic inefficiency, low status of women, extreme poverty, lack of support, culture
• China's fertility rate decreased from 5.7 in 1972 to 1.7 in 2004
• China used economic incentives, free medical care, free sterilization, and a very intrusive and coercive approach to slow population growth
• Ways to cut global population growth

  • Family planning
  • Improve health care
  • Elevate the status of women
  • Increase education
  • Involve men in parenting
  • Reduce poverty
  • Sustainability
• Urban sprawl leads to loss of crop land, forest land, and wetlands
• Urban sprawl fragments fish and wildlife habitats
• Increased impervious surfaces from urban sprawl means more flooding and soil erosion