1. The Human Population and its Impact
Chapter 6

2. Human Exponential Growth
For the past 200 years, the human pop. has grown rapidly  J-curve
Why?
ability to live in most climate zones and habitats
modern agriculture = more food
Improved sanitation and health care = drop in death rates

3. Annual Growth Rate Global Pop. growth = 1.21% per year
Growth is geographically uneven
Fig. 6-3, p. 127

4. Figure 6.4: This chart shows the populations of the world’s five most populous countries in 2010 and 2050 (projected). In 2010, more than one of every three persons on the earth lived in China (with 19% of the world’s population) or India (with 17%). (Data from United Nations Population Division)
Fig. 6-4, p. 127

5. Cultural Carrying Capacity
Maximum # of people who could live in reasonable freedom and comfort indefinitely, without decreasing the ability of the earth to sustain future generations

6. Factors Affecting Human Population Size
Population change equation
Population
Change =
(Births + Immigration) – (Deaths + Emigration)
Crude birth rate (CBR)
- # live births per 1000 people in a population in a given year
Crude death rate (CDR)
- # deaths per 1000 people in a population in a given year 6

7. Average CBR and CDR 7

8. Describing Population Changes
Doubling Times
- time (years) for a pop. growing at a specified rate to double in size
“Rule of 70”
- - EX: 2004 world’s pop. growth rate 1.2%
doubling time = 70/1.2= 56 years 8

9. Fertility
fertility rate = number of children born to a woman during her lifetime
replacement-level fertility rate = average number of children that couples in a pop. must bear to replace themselves
total fertility rate (TFR) = average number of children born to women in a pop. during their reproductive years

10. Figure 6.5: This graph tracks the total fertility rate for both the more-developed and less-developed regions of the world, 1955–2010, with projections to 2050 (based on medium population projections). Although the world’s average TFR has dropped to 2.5, it will have to drop to around 2.1 to eventually halt the world’s population growth. (Data from United Nations Population Division)
Fig. 6-5, p. 130

11. US Fertility & Birth Rates
76 mil (1900) to 294 mil (2004)
Figure 6.6: The top graph shows the total fertility rates for the United States between 1917 and 2010 and the bottom graph shows the country’s birth rate between 1917 and Question: The U.S. fertility rate has declined and remained at or below replacement levels since So why is the population of the United States still increasing? (Data from Population Reference Bureau and U.S. Census Bureau)
Fig. 6-6, p. 131

12. Factors Affecting Birth Rates
Importance of children as a part of the labor force
Cost of raising and educating children
Availability of, or lack of, private and public pension systems
Infant deaths
Urbanization

13. Factors Affecting Birth Rates
Educational and employment opportunities available for women
Average age at marriage (or average age at which a woman has her first child)
Availability of legal abortions
Availability of reliable birth control methods
Religious beliefs, traditions, and cultural norms

14. Factors Affecting Death Rates
Increased food supplies and distribution
Better nutrition
Medical advances
Improved sanitation
Safer water supplies

15. Factors Affecting Death Rates
Life expectancy
- avg. # years a newborn infant can expect to live
Infant mortality rate (IMR)
- # babies out of every 1000 born who die before their 1st birthday
GOOD NEWS
BAD NEWS
Global life expectancy increased from 48 years to 69 years
(77 developed; 67 developing)
Poorest, least developed countries life exp. 57 years or less (may drop due to internal strife, AIDS)
IMR dropped from 20 per 1000 live births to 7 in developed countries
Most infants and children die from fully preventable causes
IMR dropped from 118 per 1000 live births to 61 in developing countries 15

16. Essential Question
What are the factors that influence birth and death rates?

17. Migration
Movement of people into (immigration) and out of (emigration) specific geographic areas
Most seek jobs and economic improvement
Religious persecution, ethnic conflicts, political oppression, wars and certain types of environmental degradation cause some to migrate

18. Figure 6.11: This graph shows legal immigration to the United States, 1820–2006 (the last year for which data are available). The large increase in immigration since 1989 resulted mostly from the Immigration Reform and Control Act of 1986, which granted legal status to certain illegal immigrants who could show they had been living in the country prior to January 1, (Data from U.S. Immigration and Naturalization Service and the Pew Hispanic Center)
Fig. 6-11, p. 135

19. Age Structures
The numbers or percentages of males and females in young, middle and older age groups in that population
Prereproductive (0-14)
Reproductive (15-44)
Postreproductive (45 and older)

20. Figure 6.12: This chart represents the generalized population age-structure diagrams for countries with rapid (1.5–3%), slow (0.3–1.4%), zero (0–0.2%), and negative (declining) population growth rates. A population with a large proportion of its people in the prereproductive age group (far left) has a significant potential for rapid population growth. See an animation based on this figure at CengageNOW. Question: Which of these diagrams best represents the country where you live? (Data from Population Reference Bureau)
Fig. 6-12, p. 136

21. Figure 6.13: Global outlook: These charts illustrate population structure by age and sex in less-developed countries and more-developed countries for Question: If all girls under 15 were to have only one child during their lifetimes, how do you think these structures would change over time? (Data from United Nations Population Division and Population Reference Bureau)
Fig. 6-13, p. 136

22. Essential Question
What is an age structure diagram and what can it be used for?

23. Slowing Human Population Growth
Promote economic development
Empower women
Promote family planning
The Miniature Earth
VHEMT

24. Promote Economic Development
Reduce poverty through economic development and universal primary education
Demographic transition = as countries become industrialized and economically developed, first their death rates decline and then their birth rates decline

25. Figure 6.17: The demographic transition, which a country can experience as it becomes industrialized and more economically developed, can take place in four stages. See an animation based on this figure at CengageNOW. Question: At what stage is the country where you live?
Fig. 6-17, p. 140

26. Slow population growth
Stage 1: Preindustrial
High birth rate
High death rate
Slow population growth
Figure 6.17: The demographic transition, which a country can experience as it becomes industrialized and more economically developed, can take place in four stages. See an animation based on this figure at CengageNOW. Question: At what stage is the country where you live?
Fig. 6-17, p. 140

27. High population growth
Stage 2: Transitional
High birth rates
LOW death rates
High population growth
Figure 6.17: The demographic transition, which a country can experience as it becomes industrialized and more economically developed, can take place in four stages. See an animation based on this figure at CengageNOW. Question: At what stage is the country where you live?
Fig. 6-17, p. 140

28. Slow population growth
Stage 3: Industrial
LOW birth rate
Low death rate
Slow population growth
Figure 6.17: The demographic transition, which a country can experience as it becomes industrialized and more economically developed, can take place in four stages. See an animation based on this figure at CengageNOW. Question: At what stage is the country where you live?
Fig. 6-17, p. 140

29. Stage 4: Post-industrial
Lower birth rate
Stable death rate
Declining population growth
Figure 6.17: The demographic transition, which a country can experience as it becomes industrialized and more economically developed, can take place in four stages. See an animation based on this figure at CengageNOW. Question: At what stage is the country where you live?
Fig. 6-17, p. 140

30. Empower Women Elevate the status of women
Women tend to have fewer children if they are
Educated
Have the ability to control their own fertility
Earn an income of their own
Live in societies that do not suppress their rights

31. Promote Family Planning
Family planning = provides educational and clinical services that help couples choose how many children to have and when to have them
Most provide info on birth spacing, birth control, and health care for pregnant women and infants
Reduces number of abortions and deaths of mom/babies during pregnancy

32. Promote Family Planning Problems
Many pregnancies are unplanned
Lack of access to services
Expand to include teenagers and sexually active unmarried women
Develop programs that educate men
Greatly increase research male birth control

33. Essential Question
What are the ways in which we can slow human population growth?