Chapter 6 Review

1. Chapter 6 Review By: Ivey Floyd

2. 6.1 How Many People Can the Earth Support?

3. Population Growth on Earth • Nobody knows how many humans the Earth is able to hold. The population grows in a J curve of exponential growth. The increase is caused by the ability to expand globally, agriculture, and the drop of death rates due to better sanitation and health care (drop of death rates is the MAIN reason). Population growth has slowed but it’s ALWAYS increasing. (By about 1.21%, 83 million people a year). 99% of those people were born into less-developed countries with poverty, 1% into developed countries.

4. There isn’t really a chance for stabilizing population, but it’s possible that it might level off from a J shaped curve of exponential growth to an S shaped curve of logistic growth. [Graphs]. • The question that remains unanswered is: What is the planet’s cultural carrying capacity. (the max number of people who could live decently and comfortably while still keeping the earth where it’s able to sustain future generations)

5. Natural Capital Degradation • We alter the world to meet our needs and provide resources for us. The effects that come from this are: • Reducing biodiversity, increasing use of net primary productivity, increasing genetic resistance in pest species and disease-causing bacteria, eliminating many natural predators, introducing harmful species into natural communities, using some renewable resources faster than they can be replenished, disrupting natural chemical cycling and energy flow, and relying mostly on polluting and climate-changing fossil fuels

6. 6.2 What Factors Influence the Size of the Human Population?

7. Population can change in different ways. • Populations can grow: if there are more birth rates than death rates (births>deaths) • Decline: If there are more death rates than birth rates (deaths>births) • Remain fairly stable: If birth and death rates are almost equal (births=deaths) • Crude birth rate: the number of live births per 1,000 people in a population in a given year • Crude death rate (the number of deaths per 1,000 people in a population in a given year). • Population change can be calculated with this: (Births + Immigration) – (Deaths + Emigration)= Population Change

8. Fewer babies but not few enough to stabilize population • Fertility rate: the number of children born to a woman during her lifetime. • Replacement-level fertility rate: average number of kids that couples must have to replace themselves. • Total fertility rate (TFR): average number of children born to women in a population during their reproductive years. • Population in more developed countries is slower than in less developed countries. • Migration: the movement of people into (immigration) and out of (emigration) specific geographic areas • Life expectancy: the average number of years a newborn infant can be expected to live • Infant mortality rate: the number of babies out of every 1,000 born who die before their first birthday

9. Factors that affect birth/fertility rates • The importance of children as a part of the labor force • The cost of raising and educating children • The availability of, or lack of, private and public pension systems • Urbanization • The educational and employment opportunities available for women • Average age at marriage • Availability of legal abortions • Religious beliefs, traditions, and cultural norms

10. 6.3 How Does a Population’s Age Structure Affect its Growth or Decline?

11. Demographics of the population • Age structure: the numbers or percentages of males and females in young, middle, and older age groups in that population. • Demographic momentum: the number of births will rise for several decades even if women have an average of only one or two children, due to the large number of girls entering their prime reproductive years.

12. Types of age structure • Pre-reproductive (children, babies, preteens), consisting of individuals normally too young to have children • Reproductive (teenagers to middle aged adults), consisting of those normally able to have children • Post-reproductive, (elders) with individuals normally too old to have children.

13. Issues with rapid population decline • Can threaten economic growth • Labor shortages • Less government revenues with fewer workers • Less entrepreneurship and new business formation • Less likelihood for new technology development • Increasing public deficits to fund higher pension and health-care costs • Pensions may be cut and retirement age increased

14. 6.4 How Can We Slow Human Population Growth?

15. We have 3 important goals • To reduce poverty primarily through economic development and universal primary education • To elevate the status of women • To encourage family planning and reproductive health care • As countries become more developed and demographic transition occurs, there are less births.

16. Parts of demographic transition • Preindustrial: Population grows very slowly because of a high birth rate (to compensate for high infant mortality) and a high death rate • Transitional: Population grows rapidly because birth rates are high and death rates drop because of improved food production and health • Industrial: Population growth slows as both birth and death rates drop because of improved food production, health, and education • Postindustrial: Population growth levels off and then declines as birth rates equal and then fall below death rates

18. Family Planning • Family planning provides educational and clinical services that help couples choose how many children to have and when to have them. • 42% of all pregnancies in less-developed countries are unplanned and 26% end with abortion • About 201 million couples in less- developed countries want to limit their number of children and determine their spacing, but they lack access to family planning services. • It’s suggested that the best ways to slow and stabilize population growth are through promoting economic development, elevating the social and economic status of women, and encouraging family planning

19. 3 Big Ideas • The human population is increasing rapidly and may soon bump up against environmental limits. • Even if population growth were not a serious problem, the increasing use of resources per person is expanding the overall human ecological footprint and putting a strain on the earth’s resources. • We can slow human population growth by reducing poverty through economic development, elevating the status of women, and encouraging family planning.