Chapter 12

1. Chapter 12 Human Population: Growth, Demography, and Carrying Capacity

2. Is the World Overpopulated? • Much of the world’s population growth occurs in developing countries like China and India. Figure 9-1

3. Is the World Overpopulated? • Some argue that the planet has too many people. • Some feel that the world can support billions of more people due to technological advances. • There is a constant debate over the need to reduce population growth. • Must consider moral, religious, and personal freedom.

4. How Would You Vote? • Should the population of the country where you live be stabilized as soon as possible? • a) Yes. Governments should use incentives and penalties. • b) Yes. However, only through indirect means, like education, or by relying on demographic transition. • c) No. The population of my country could continue to grow without serious consequences.

5. HUMAN POPULATION GROWTH:A BRIEF HISTORY • The human population has grown rapidly because of the expansion of agriculture and industrial production and lower death rates from improvements in hygiene and medicine. • In 2006, the population of developed countries grew exponentially at 0.1% per year. • Developing countries grew (15 times faster at 1.5% per year.

6. Where Are We Headed? • We do not know how long we can continue increasing the earth’s carrying capacity for humans. • There are likely to be between 7.2-10.6 billion people on earth by 2050. • 97% of growth in developing countries living in acute poverty. • What is the optimum sustainable population of the earth based on the cultural carrying capacity?

7. World Population Growth Through History Billions 12 11 2100 10 9 Modern Age Old 8 Iron Middle Bronze Stone Age New Stone Age Ages Age Age 7 Future 6 2000 5 4 1975 3 1950 2 1900 1 1800 Black Death — The Plague 2000 1+ million 7000 6000 5000 3000 1000 A.D. 4000 A.D. A.D. A.D. A.D. A.D. years B.C. B.C. B.C. B.C. B.C. B.C. B.C. 1 1000 2000 3000 4000 5000 Source: Population Reference Bureau; and United Nations, World Population Projections to 2100 (1998).

8. World Population Growth, in Billions Number of years to add each billion (year) All of Human History (1800) 130 (1930) 30 (1960) 15 (1975) 12 (1987) 12 (1999) 14 (2013) 14 (2027) 21 (2048) Sources: First and second billion: Population Reference Bureau. Third through ninth billion: United Nations, World Population Prospects: The 2004 Revision (medium scenario), 2005.

9. Animation: Current and Projected Population Sizes by Region PLAY ANIMATION

10. Where Are We Headed? • U.N. world population projection based on women having an average of 2.5 (high), 2.0 (medium), or 1.5 (low) children. Figure 9-2

11. FACTORS AFFECTING HUMAN POPULATION SIZE • Population increases because of births and immigration and decreases through deaths and emigration. • Instead of using raw numbers, crude birth rates and crude death rates are used (based on total number of births or deaths per 1,000 people in a population).

12. FACTORS AFFECTING HUMAN POPULATION SIZE • Average crude and birth rates for various groupings of countries in 2006. Figure 9-3

13. FACTORS AFFECTING HUMAN POPULATION SIZE • The world’s 10 most populous countries in 2006 with projections in 2025. Figure 9-4

14. Declining Fertility Rates: Fewer Babies per Women • The average number of children that a woman bears has dropped sharply. • This decline is not low enough to stabilize the world’s population in the near future. • Replacement-level fertility: the number of children a couple must bear to replace themselves. • Total fertility rate (TFR): the average number of children a woman has during her reproductive years.

15. Declining Fertility Rates: Fewer Babies per Women • The replacement level to sustain a population is 2.0 children. • In 2006, the average global Total Fertility Rate was 2.7 children per woman. • 1.6 in developed countries (down from 2.5 in 1950). • 3.0 in developing countries (down from 6.5 in 1950).

16. Case Study: Fertility and Birth Rates in the United States • Nearly 2.9 million people were added to the U.S. in 2006: • 59% occurred because of births outnumbering deaths. • 41% came from illegal and legal immigration.

17. Case Study: Fertility and Birth Rates in the United States • In 2006, the total fertility rate in the United States was slightly > 2.0 Figure 9-5

18. Case Study: Fertility and Birth Rates in the United States • The baby bust that followed the baby boom was largely due to delayed marriage, contraception, and abortion. Figure 9-6

19. 47 years Life expectancy 77 years 8% Married women working outside the home 81% 15% High school graduates 83% 10% Homes with flush toilets 98% 2% Homes with electricity 99% 10% Living in suburbs 52% 1900 Hourly manufacturing job wage (adjusted for inflation) $3 2000 $15 1.2 Homicides per 100,000 people 5.8 Fig. 9-7, p. 176

20. Factors Affecting Birth Rates and Fertility Rates • The number of children women have is affected by: • The cost of raising and educating them. • Availability of pensions. • Urbanization. • Education and employment opportunities. • Infant deaths. • Marriage age. • Availability of contraception and abortion.

21. Factors Affecting Death Rates • Death rates have declined because of: • Increased food supplies, better nutrition. • Advances in medicine. • Improved sanitation and personal hygiene. • Safer water supplies. • U.S. infant mortality is higher than it could be (ranked 46th world-wide) due to: • Inadequate pre- and post-natal care for poor. • Drug addiction. • High teenage birth rate.

22. Case Study: U.S. Immigration • Since 1820, the U.S. has admitted almost twice as many immigrants and refugees as all other countries combined. Figure 9-8

23. How Would You Vote? • Should legal immigration into the United States (or the country where you live) be reduced? • a) Yes: Because of threats of terrorism and the burden on the economy, immigration should be reduced. • b) No. Humane efforts should be made to curtail illegal immigration, but our economy needs legal immigrants.

24. POPULATION AGE STRUCTURE • The number of people in young, middle, and older age groups determines how fast populations grow or decline. • The number of people younger than age 15 is the major factor determining a country’s population growth. • Changes in the distribution of a country’s age groups have long-lasting economic and social impacts.

25. POPULATION AGE STRUCTURE • Populations with a large proportion of its people in the preproductive ages 1-14 have a large potential for rapid population growth. Figure 9-9

26. POPULATION AGE STRUCTURE • 32% of the people in developing countries were under 15 years old in 2006 versus only 17% in developed countries. Figure 9-10

27. POPULATION AGE STRUCTURE • Today, baby boomers make up nearly half of all adult Americans and dominate the populations demand for goods and services. Figure 9-11

28. Animation: U.S. Age Structure PLAY ANIMATION

29. POPULATION AGE STRUCTURE • About 14% of the world’s population live in countries with stabilizing or declining populations. • Rapid population decline can lead to long-lasting economic and social problems. • Death from AIDS can disrupt a country’s social and economic structure by removing significant numbers of young adults. • Global again may help promote peace.

30. POPULATION AGE STRUCTURE • Age structure predictions based on a medium fertility projection. • The cost of an aging population will strain the global economy. Figure 9-12

31. Video: Bonus For A Baby PLAY VIDEO • From ABC News, Environmental Science in the Headlines, 2005 DVD.

32. POPULATION AGE STRUCTURE • Some problems with rapid population decline. • Which of these problems do you believe are the most important? Figure 9-13

33. SOLUTIONS: INFLUENCING POPULATION SIZE • Demographic Transition: As countries become economically developed, their birth and death rates tend to decline. • Preindustrial stage: little population growth due to high infant mortality. • Transitional stage: industrialization begins, death rates drops and birth rates remain high. • Industrial stage: birth rate drops and approaches death rate.

34. Most developing countries at the Transitional Stage • · Death rates have fallen much more that birth rates • · Many countries caught in demographic trap, still rapid population • growth outstrips economic growth and overwhelms local life-support • systems • o Many African countries with rising death rates moving back to stage one

35. · Many developing countries lack the resource to move to the next stage • o Not enough skilled workers • o Lack capital and resources for rapid economic development • o Economic assistance from developed countries has dropped since • 1980 and developing countries have paid $40-50 billion in debt interest

36. Do the developed countries have a responsibility to foster economic • growth in developing countries ? • Controlling population with: • · Family planning • · Empowering women • · Economic rewards and penalties

37. Animation: Demographic Transition Model PLAY ANIMATION

38. SOLUTIONS: INFLUENCING POPULATION SIZE • Generalized model of demographic transition. • Some developing countries may have difficulty making the demographic transition. Figure 9-14

39. SOLUTIONS: INFLUENCING POPULATION SIZE • Family planning has been a major factor in reducing the number of births and abortions throughout most of the world. • Women tend to have fewer children if they are: • Educated. • Hold a paying job outside the home. • Do not have their human right suppressed.

40. SOLUTIONS: INFLUENCING POPULATION SIZE • The best way to slow population growth is a combination of: • Investing in family planning. • Reducing poverty. • Elevating the status of women.

41. SLOWING POPULATION GROWTH IN INDIA AND CHINA • For more than five decades, India has tried to control its population growth with only modest success. • Since 1970, China has used a government-enforced program to cut its birth rate in half and sharply reduce its fertility rate.

42. Percentage of world population India 17% China 20% 1.1 billion Population 1.3 billion 1.4 billion Population (2050) (estimated) 1.6 billion 47% Illiteracy (% of adults) 17% 36% Population under age 15 (%) 20% 1.6% Population growth rate (%) 0.6% 2.9 children per women (down from 5.3 in 1970) Total fertility rate 1.6 children per women (down from 5.7 in 1972) 58 Infant mortality rate 27 62 years Life expectancy 70 years Percentage living below $2 per day 80 47 $3,120 GDP PPP per capita $5,890 Fig. 9-15, p. 186

43. India’s Failed Family Planning Program • Poor planning. • Bureaucratic inefficiency. • Low status of women. • Extreme poverty. • Lack of administrative financial support. • Disagreement over the best ways to slow population growth.

44. India • · In 1952 began national family planning program • · Population still continues to grow rapidly • · TFR dropped from 5.3 in 1970 to 3.2 in 2002 • Added 18 million in 2002 and will soon overtake • China as the worlds most populous country • · 90% couples know about modern birth control methods, only 43% actually use one • Couples still believe they need children to work and to care for them in old age. • · Overall, a poor country, 30% living on $2 per day or less • · Nearly half of the labor force is unemployed • · 53% of its children suffer from malnutrition • · Resource poor • 16% of world’s population • 2.3 % of the world’s land resources • Land is being degraded by poor farming practices • · 70% of the water supply seriously polluted

45. China’s Family Planning Program • Currently, China’s TFR is 1.6 children per women. • China has moved 300 million people out of poverty. • Problems: • Strong male preference leads to gender imbalance. • Average population age is increasing. • Not enough resource to support population.

46. China • · Cut TFR from 5.7 to 1.8 • · Couples strongly urged to postpone the age at which they marry and to have no more than one child • · Married couples have free access • o Free sterilization • o Contraception • o Abortion • · Married couples who pledge to have no more than one child • o Extra food • o Larger pensions • o Better housing • o Free medical care • o Salary bonuses • o Free tuition for one child • o Preferential treatment for their one child when he/she enters the job • market. • · Program has been highly effective, but at what cost ?

47. United Nations Conference on Population and Development • · Held every decade • · Held last decade in Cairo, Egypt 1994 • · Goal: to stabilize the world population at 7.8 billion by 2050 • · Methods 1. Invest 17 billion by the year 2000 • 2/3 from developing countries • 1/3 from developed countries 2. Invest in family planning • Distribution • Education • 3. Elevate the status of women • Education opportunities • Business opportunities • 4. Eliminate • Developing countries have paid 70 % of their part of the $17 billion • Developed nations have paid only 40% of their part • Much has been done, but much still needs to be done…. • o

48. HUMAN ASPECTS ON NATURAL SYSTEMS • Excluding Antarctica, human activities have affect about 83% of the earths land surface. Figure 9-16

49. HUMAN ASPECTS ON NATURAL SYSTEMS • We have used technology to alter much of the rest of nature in ways that threaten the survival of many other species and could reduce the quality of life for our own species. Figure 9-17

50. Animation: Resources Depletion and Degradation PLAY ANIMATION