1. Chapter 6 Lecture Presentations prepared by Reggie Cobb Nash Community College Human Population © 2015 Pearson Education, Inc.

2. This lecture will help you understand: Human population growth Population, affluence, and technology’s effects Demography Demographic transition Factors affecting population growth © 2015 Pearson Education, Inc.

3. Central Case Study: China’s One-Child Policy In 1970, China’s 790 million people faced starvation The government instituted a one-child policy The growth rate plummeted The policy is now less strict but has unwanted consequences: Killing of female infants Black-market trade in teenaged girls © 2015 Pearson Education, Inc.

4. Central Case Study: China’s One-Child Policy (cont’d) One-child policy has led to a shrinking workforce © 2015 Pearson Education, Inc.

5. Our world at seven billion Populations continue to rise in most countries Particularly in poverty-stricken developing nations Although the rate of growth is slowing, we are still increasing in numbers India will soon surpass China as most populous © 2015 Pearson Education, Inc.

6. Frequently Asked Question How big is a billion? Analogy: How long would it take a banker to count out $1 million at a rate of a dollar a second for 8 hours a day, 7 days a week? How long would it take to count $1 billion at the same rate? © 2015 Pearson Education, Inc.

7. The human population is growing rapidly Our population grows by over 80 million each year It took until 1800 to reach 1 billion 130 more years to reach 2 billion Only 30 years to reach 3 billion Human population continues to grow exponentially 3 billion in the last 12 years Because of exponential growth (increase by a fixed %), even if the growth rate remains steady, population size will continue to increase © 2015 Pearson Education, Inc.

8. Growth rates vary from region to region At today’s 1.2% global growth rate, the population will double in 58 years Highest growth rate is in developing countries © 2015 Pearson Education, Inc.

9. Is there a limit to population growth? Technology, sanitation, medication, and food increase population by reducing infant mortality rates Death rates drop, but not birth rates Earth’s carrying capacity for people? 1–2 billion prosperous people 33 billion very poor people Thomas Malthus’ An Essay on the Principles of Population (1798) War, disease, starvation will reduce populations © 2015 Pearson Education, Inc.

10. Different views on population growth Paul Ehrlich’s The Population Bomb (1968) predicted that population growth would lead to famine and conflict But intensified food production fed more people Many economists think depleted resources will be replaced or new resources created But many resources (e.g., species) cannot be replaced Quality of life will suffer with unchecked growth Less space, food, wealth per person Population growth is a problem if it depletes resources, stresses social systems, and degrades the environment © 2015 Pearson Education, Inc.

11. Population is one of several factors that affect the environment The IPAT model: I  P  A  T Our total impact (I) on the environment results from: Population (P): individuals need space and resources Affluence (A): per capita resource use Technology (T): increases use of, or protects, resources Sensitivity (S): a fourth factor showing how sensitive an area is to human pressure Further model refinements include the effects of education, laws, and ethics on the formula © 2015 Pearson Education, Inc.

12. China is an example of the IPAT formula Elements of the IPAT equation can combine Causing tremendous impact in a very short time Modern China’s rapid development is causing unprecedented environmental challenges Intensive agriculture is eroding farmland Overuse has dried up the mighty Yellow River Increasing vehicles are causing urban air pollution and massive traffic jams China shows us what the rest of the world can become © 2015 Pearson Education, Inc.

13. Demography is the study of human population Demography Applying principles of population ecology to the study of change in human populations Demographers study: Population size Density and distribution Age structure Sex ratio Birth, death, immigration, and emigration rates © 2015 Pearson Education, Inc.

14. Population size and density The UN predicts 9.3 billion humans by 2050 If women have just 0.5 child fewer than the medium scenario, there will be 8, not 9.3, billion by 2050 © 2015 Pearson Education, Inc.

15. Population density and distribution Humans are unevenly distributed around the globe Most populated areas Regions with temperate, subtropical, and tropical climates Seacoasts and rivers Many unpopulated areas (e.g., deserts, arid grasslands) are environmentally sensitive High S value in the modified IPAT equation Vulnerable to humans (agriculture, ranching, etc.) © 2015 Pearson Education, Inc.

16. Age structure Describes relative numbers of individuals in each age class within a population Shown by age structure diagrams (population pyramids) © 2015 Pearson Education, Inc.

17. Age structure (cont’d) Wide base Many young that haven’t reproduced yet Population will soon increase rapidly Even age distribution: Remains stable Births  deaths © 2015 Pearson Education, Inc.

18. Age structures: Canada vs. Nigeria Canada’s age structure is balanced (growth rate  0.4%) Nigeria’s age structure is heavily weighted toward the young (growth rate  2.8%) © 2015 Pearson Education, Inc.

19. Many populations are aging The global mean age is now 28—in 2050… 38 China’s age structure is changing In 1970, the median age was 20 By 2050, it will be 45 Although fewer people will be working to support social programs, retirees can contribute time and experience toward productive volunteer efforts © 2015 Pearson Education, Inc.

20. Sex ratios Human sex ratios at birth slightly favor males For every 100 females born, 106 males are born Evolutionary adaptation, since males are more prone to death during any given year of life Tends to ensure that the ratio of men to women is equal at reproductive age Chinese females are selectively aborted 120 boys were reported for 100 girls The undesirable social consequences? Teenaged girls are kidnapped and sold as brides Many single Chinese men Some engage in more risky sexual behavior, which can lead to higher incidence of HIV in China © 2015 Pearson Education, Inc.

21. Weighing the Issues China’s Reproductive Policy Describe what benefits may come from a reproductive policy such as China’s. Now describe several problems that may result. Do you think a government should be able to enforce strict penalties for citizens who fail to abide by such a policy? Why or why not? What alternatives to China’s policy can you suggest for dealing with the resource demands of a rapidly growing population? © 2015 Pearson Education, Inc.

22. Population change results from birth, death, immigration, and emigration Rates of birth, death, and migration determine whether a population grows, shrinks, or remains stable Birth and immigration add individuals Death and emigration remove individuals Technological advances decrease death rates The increased gap between birth and death rates resulted in population expansion Decrease in infant mortality Due to better nutrition, prenatal care, and presence of medically trained practitioners during birth © 2015 Pearson Education, Inc.

23. Infant mortality rates vary around the world Infant mortality rates are closely tied with level of industrialization Highest in poorer nations (sub-Saharan Africa) Lowest in wealthier nations © 2015 Pearson Education, Inc.

24. Falling growth rates do not mean fewer people Despite decline in global growth rate, the population continues growing by adding tens of millions of people each year © 2015 Pearson Education, Inc.

25. Total fertility rate influences population growth Total fertility rate (TFR) Average number of children born to each female during her lifetime Replacement fertility TFR that keeps the population size stable (about 2.1) Causes of decreasing TFR Medical care reduces infant mortality Urbanization increases childcare costs Children go to school instead of working Social Security supports the elderly Educated women enter the labor force © 2015 Pearson Education, Inc.

26. Total fertility rate influences population growth (cont’d) Rate of natural increase (natural rate of population change) Change due to birth and death rates alone (excluding migration) Europe’s rate: 0.0–0.1% 18 of 45 European nations have declining populations Worldwide by 2013 TFR of 77 countries below replacement fertility of 2.1 © 2015 Pearson Education, Inc.

27. Frequently Asked Question Why hasn’t AIDS drastically lowered Africa’s fertility rates? © 2015 Pearson Education, Inc.

28. Many nations have experienced the demographic transition Demographic transition A model of economic and cultural change As nations industrialize, they move from a stable pre- industrial state of high birth and death rates To a stable post-industrial state of low birth and death rates Industrialization decreases mortality rates So there is less need for large families Parents invest in quality of life, not quantity of kids Death rates fall before birth rates Resulting in temporary population growth © 2015 Pearson Education, Inc.

29. Data Question: Demographic Transition In which stage of the demographic transition does the population increase the most? Is the growth greatest at the beginning or the end of this stage? © 2015 Pearson Education, Inc.

30. The 4 stages of the demographic transition Pre-industrial stage: low population growth High death (disease, starvation, few medicines) and birth (compensation for mortality) rates Transitional stage: high population growth Industrialization, increased food, and medical care reduce mortality rates but birth rates are still high Industrial stage: population growth decreases Women get jobs and use birth control Kids do not need to help produce food Post-industrial stage: population stabilizes Low birth and death rates © 2015 Pearson Education, Inc.

31. Is the demographic transition a universal process? Demographic transition has occurred in Europe, the U.S., Canada, Japan, and other nations over the past 200–300 years But it may or may not apply to developing nations The transition could fail: If the population is too large to allow the transition In cultures that place greater value on childbirth or grant women fewer freedoms For people of all nations to attain the material standard of living of North Americans, we would need the natural resources of 3 more Earths © 2015 Pearson Education, Inc.

32. Population and society Factors that affect fertility in a society Public health factors Access to medical care Infant mortality rate Culture factors Religious traditions Degree of gender equality Relative acceptance of contraceptive use Economic factors Level of affluence Degree of child labor Availability of governmental support for retirees © 2015 Pearson Education, Inc.

33. Family planning is a key approach for controlling population growth Family planning Efforts to plan the number and spacing of children The greatest single factor slowing population growth Clinics offer advice, information, and contraceptives Birth control Controlling the number of children born by reducing the frequency of pregnancy Contraception Deliberate prevention of pregnancy through a variety of methods Hindered by religious and cultural influences Rates range from below 10% (Africa) to 86% (China) © 2015 Pearson Education, Inc.

34. Reproductive window Time when women can become pregnant Decisions that affect their reproductive window Jobs or school: delays the birth of a first child Contraceptives: space births Women may “close” the window after she reaches the desired family size © 2015 Pearson Education, Inc.

35. Family-planning programs are working around the world Funding and policies that encourage family planning lower population growth rates in all nations Thailand’s education-based approach to family planning reduced its growth rate from 2.3% to 0.4% Brazil, Mexico, Iran, Cuba, and other developing countries have active programs 1994’s UN population and development conference in Cairo, Egypt, called for universal access to reproductive health care Offer education and health care, and address social needs © 2015 Pearson Education, Inc.

36. Weighing the Issues Abstain from International Family Planning? The U.S. and 180 other nations have provided millions of dollars to the United Nations Populations Fund (UNFPA), which advises governments on family planning, sustainable development, poverty reduction, reproductive health, and AIDS prevention. Should the United States fund family-planning efforts in other nations? What conditions, if any, should it place on the use of such funds? © 2015 Pearson Education, Inc.

37. Empowering women reduces fertility rates A nation’s fertility rates drop when women gain access to: Contraceptives Family-planning programs Educational opportunities Educating women reduces fertility rates, delays childbirth, and gives them a voice in reproductive decisions Exposing women to strong empowered women helps improve women’s rights Relatives, social workers, politicians, women on television © 2015 Pearson Education, Inc.

38. The Science Behind the Story Did Soap Operas Reduce Fertility in Brazil? They are a surprising cultural force for promoting lower fertility Telenovelas (soap operas) Watched by people of all ages, races, and incomes Characters, settings, and plots of everyday Brazilians Brazil’s nonintrusive governmental policies have helped decreased their TFR to 1.9 Equal access to education for women 40% of workforce is now women Free family planning and contraception © 2015 Pearson Education, Inc.

39. The Science Behind the Story (cont’d) Telenovelas promote a vision of an “ideal” Brazilian family Middle or upper class Materialistic Individualistic Full of empowered women Rede Globo network now reaches 98% of Brazilian households Main network with telenovelas Other networks that imported programming from other nations did not show correlation with reduced fertility © 2015 Pearson Education, Inc.

40. The Science Behind the Story (cont’d) Fertility declines were age-related Fertility reductions occurred in women ages 25–44, but not in younger women Women of these ages were closer in age to the main female characters in the telenovelas Television’s ability to influence fertility is not limited to Brazil In the United States, Tweets and Google searches for terms such as “birth control” increased significantly the day following airing of “MTV’s 16 and Pregnant” MTV’s “Teen Mom” series may have been responsible for reducing teenage births by up to 20,000 per year © 2015 Pearson Education, Inc.

41. Increasing affluence lowers fertility Poor societies have higher population growth rates Poverty and population growth make each other worse 99% of the next billion people added will be born in poor, less developed regions that are least able to support them © 2015 Pearson Education, Inc.

42. Expanding wealth can increase the environmental impact per person Affluent societies have enormous resource consumption With severe, far-reaching environmental impacts Ecological footprints are huge One American has as much environmental impact as 3.4 Chinese or 8 Indians or 14 Afghans © 2015 Pearson Education, Inc.

43. We must reduce population growth and consumption For a high standard of living and quality of life for all, developing nations must slow their population growth Their consumption is also increasing Developed nations must slow their consumption Our global ecological footprint is 50% more than the Earth can support © 2015 Pearson Education, Inc.

44. Conclusion The human population is larger than it has ever been Rates are decreasing, but populations are still rising Most developed nations have passed through the demographic transition Expanding women’s rights slows population growth How will the population stop rising? The demographic transition, governmental intervention, or disease and social conflict? © 2015 Pearson Education, Inc.