The Human Population and Its Impact Chapter 6

6-2 What Factors Influence the Size of the Human Population?  Concept 6-2A Population size increases because of births and immigration and decreases through deaths and emigration.  Concept 6-2B The average number of children born to women in a population (total fertility rate) is the key factor that determines population size.

The Human Population Can Grow, Decline, or Remain Fairly Stable  Population change Births: fertility Deaths: mortality Migration  Population change = (births + immigration) – (deaths + emigration)  Crude birth rate:number of births per 1,000 people in a year  Crude death rate: number of deaths per 1,000 people in a year

Global Connections: The World’s 10 Most Populous Countries in 2008

Women Having Fewer Babies but Not Few Enough to Stabilize the World’s Population  Fertility rate Number of children born to a woman during her lifetime Replacement-level fertility rate: number of children to replace a couple (typically at or around 2 children) Total fertility rate (TFR): average # of children born to women in a population during their reproductive years Key factor to determining population size. HOW?

Birth Rates in the U.S. from 1910 to 2008

TFR Rates for the U.S. between 1917 and 2008

Some Major Changes That Took Place in the U.S. between 1900 and 2000

Several Factors Affect Birth Rates and Fertility Rates (1)  Children as part of the labor force  Cost of raising and educating children  Availability of private and public pension  Urbanization  Educational and employment opportunities for women

Several Factors Affect Birth Rates and Fertility Rates (2)  Infant mortality rate  Average age of a woman at birth of first child  Availability of legal abortions  Availability of reliable birth control methods  Religious beliefs, traditions, and cultural norms

Several Factors Affect Death Rates (1)  Life expectancy: average # years a newborn infant can expect to live  Infant mortality rate: # of babies out of every 1,000 born who die before 1 st birthday  Why are people living longer and fewer infants dying? Increased food supply and distribution Better nutrition Medical advances Improved sanitation

Several Factors Affect Death Rates (2)  U.S. infant mortality rate high due to Inadequate health care for poor women during pregnancy and their infants Drug addiction among pregnant women High birth rate among teenagers

Case Study: The United States: A Nation of Immigrants  Historical role of immigration in the U.S.  Legal immigration  Illegal immigration

6-3 How Does a Population’s Age Structure Affect Its Growth or Decline?  Concept 6-3 The numbers of males and females in young, middle, and older age groups determine how fast a population grows or declines.

Populations Made Up Mostly of Young People Can Grow Rapidly  **************Age structure categories & pyramids Prereproductive ages Reproductive ages Postreproductive ages

Generalized Population Age Structure Diagrams

Population Structure by Age and Sex in Developing and Developed Countries

We Can Use Age-Structure Information to Make Population and Economic Projections  Baby boomers: adults who were born between and make up about half of all adult americans  Job market when they retire

Some Problems with Rapid Population Decline

6-4 How Can We Slow Human Population Growth?  Concept 6-4 Experience indicates that the most effective ways to slow human population growth are to encourage family planning, to reduce poverty, and to elevate the status of women.

As Countries Develop, Their Populations Tend to Grow More Slowly  Demographic transition stages Preindustrial Transitional May lead to a demographic trap Industrial Postindustrial

Planning for Babies Works  Family Planning Responsible for a 55% drop in TFRs In developing countries Expansion of program Include teenagers, sexually active unmarried women, and men  Slow and stabilize population growth Invest in family planning Reduce poverty Elevate the social and economic status of women

Empowering Women Can Slow Population Growth  Education  Paying jobs  Human rights without suppression

Case Study: Slowing Population Growth in China: the One-Child Policy  Encourages fewer children  Gender imbalance  Fast-growing economy  Face serious resource and environmental problems

Case Study: Slowing Population Growth in India  Population control: gender bias  Poverty  Malnutrition  Environmental problems

4. Case Studies © Brooks/Cole Publishing Company / ITP Immigration in the United States: As fertility decreases, immigration has become a major source of population increase in the U.S. In 1998 the U.S. received about 935,000 legal immigrants and 400,000 illegal immigrants--40% of our annual population growth! Working immigrants boost the economy in the long run Increasing levels of legal and illegal are expected. Fig.11–17

Case Studies © Brooks/Cole Publishing Company / ITP Population Control in India: In 1952 India began the first national family planning program The program has been disappointing in India because of poor planning, inefficiency, low status of women, extreme poverty, and lack of funds Couples still have an average of 3.5 children because of the belief that they need children to work and care for them in old age. Fig.11–16

Case Studies © Brooks/Cole Publishing Company / ITP Population Control in China: Since 1970, China, with the world's largest population, has initiated efforts to better feed its people and control population growth Family planning successful Strict population control measures prevent couples from having more than one child ** See book Although considered coercive, the policy is significantly slowing population growth. Fig.11–16