1. CHAPTER 6 OUTLINE

2. 6-1 How Many People Can the Earth Support?

3. Human Population Growth Continues but Is Unevenly Distributed In the past 200 years the human population has been growing exponentially (J-curve). Three major factors of population growth: 1)ability of humans to expand into all of earths climate zones and habitats 2)emergence of modern agriculture allows us to produce more food 3)improvements in sanitation & health care and the development of antibiotics & vaccines have resulted in a drop of death rates

4. Continued 10,000 years ago the earth’s population was 5 million humans; now there are about 6.9 billion. Population growth is unevenly distributed. “Demographers” make population forecasts.

5. Continued Human population growth can level off from a J-shaped curve to an S-shaped curve. This can happen due to various limiting factors. How many people can the earth support indefinitely? What’s the planet’s cultural carrying capacity?

6. 6-2 What Factors Influence the Size of the Human Population?

7. The Human Population Can Grow, Decline, or Remain Fairly Stable Crude birth rate: the number of live births per 1,000 people in the population in a given year. Crude death rate: number of deaths per 1,000 people in the population in a given year. Human population growth increases/decreases in particular regions based on births, deaths, and migration. Population change= (births + immigration) - (deaths+ emigration)

8. Women Are 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: average number of children that couples in a population must have to replace themselves. 2.1 in developed countries, 2.5 in developing countries. Total fertility rate: average number of children born to women in a population during their reproductive years.

9. Several Factors Affect Birth Rates and Fertility Rates Importance of children as a part of the labor force. Cost of raising and educating children. Availability of/lack of private and public pension systems. Infant deaths Urbanization. Educational and employment opportunities for women.

10. Continued Average age at marriage. Availability of legal abortions. Availability of reliable birth control methods. Religious beliefs, traditions, and cultural norms.

11. Several Factors Affect Death Rates Better food supplies and nutrition, and safer water supplies contribute to people living longer. Advances in medicine and public health, and improved sanitation and personal hygiene also contribute to people living longer.

12. Migration Affects an Area’s Population Migration: the movement of people into and out of specific geographic areas. Most people migrate seeking jobs and economic improvement. Religious persecution, ethnic conflicts, political oppression, wars, and certain types of environmental degradation also drive people to migrate.

13. 6-3 How Does A Population’s Age Structure Affect Its Growth or Decline?

14. A Population’s Age Structure Helps Us to Make Projections Age Structure: the number or percentages of males and females in young, middle, and older age groups in that population. Population experts construct a population age structure diagram by plotting a given population’s percentages of males and females in each of three age categories.

15. Continued Three categories: 1)prereproductive (ages 0-14) individuals normally too young to have children. 2)reproductive (ages 15-44) those normally able to have children. 3)postreproductive (ages 45 & up) individuals too old to have children.

16. Populations Made Up Mostly of Older People can Decline Rapidly A gradual population decline can have the following side effects: 1)produces a sharp rise in public service costs, etc. 2)may have many fewer working taxpayers and labor shortages 3)May be necessary to raise retirement age, raise taxes, cut retirement benefits, and increase legal immigration, which are generally unpopular moves.

17. Populations can Decline Due to a Rising Death Rate: The AIDS Tragedy Deaths from diseases such as AIDS disrupt a country’s social and economic structure. Large removal of a significant number of young adults from a population. Reduce the spread of HIV through education and health care and to provide financial help for education, health care, and volunteer teachers and social workers to compensate for the lost young adults.

18. 6-4 How Can We Slow Human Population Growth?

19. The First Step Is to Promote Economic Development Three most important steps to slowing down population growth: 1)reduce poverty 2)elevate the status of women 3)encourage family planning

20. Continued Demographic transition: hypothesis states that as countries become industrialized, first their death rates rise and then their birth rates decline. There are four distinct stages of the demographic transition: 1)preindustrial 2)transitional 3)industrial 4)postindustrial

21. Empowering Women Helps to Slow Population Growth Women tend to have fewer children if they are educated, have the ability to control their own fertility, earn an income of their own, and live in societies that to not suppress their rights. Globally, women account for 2/3’s of the all hours worked but receive 10% of the world’s income, and own less than 2% of the world’s land. Women make up 70% of the world’s poor and 64% of its 800 million illiterate adults.

22. Continued Teaching women to read has a major impact on fertility rates and population growth. An increasing number of women in developing countries are taking charge of their live and reproductive behavior. Such changes made by individual women will play an important role in stabilizing populations, reducing poverty and environmental degradation, and allowing more access to basic human rights.

23. Promote Family Planning Family planning provides educational and clinical services that help couples choose how many children to have and when to have them. Information is given on birth spacing, birth control, and health care. Also helps reduce the number of births and abortions throughout the world. Responsible for at least 55% of the drop in TFRs in developing countries.

24. Continued 42% of pregnancies in developing countries are unplanned and 26% end in abortion. Women want to limit their pregnancies but have no access to contraceptives. Family planning has financial benefits. Some analysts call for expanding family planning programs to include teenagers and sexually active unmarried women. Another suggestion is to develop programs that educate men on the importance of having fewer children and taking more responsibility for raising them.

25. Science Focus

26. Projecting Population Change There are countless factors population experts consider when making projections for any country or region of the world. First, they have to determine the reliability of current population estimates. Second, demographers make assumptions about trends in fertility. Third, population projections are made by a variety of organizations employing demographers.

27. How Long Can the Human Population Keep Growing? Human activities have directly affected about 83% of the earth’s land surface, excluding Antarctica. No population can continue growing indefinitely. Excessive and wasteful resource consumption increases the environmental impact, or ecological footprint, of each person. At today’s level of consumption, scientists estimate that we would need the equivalent of 1.3 planet earths to sustain our per capita use of renewable resources indefinitely.

28. Case Studies

29. Slowing Population Growth in China: A Success Story China is the world’s most populous country, with 1.3 billion people. In 1960, in order to avoid a serious threat of mass starvation due to a rapidly growing population, government officials established the world’s most extensive, intrusive, and strict family planning and birth control program. Their goal in this has been to sharply reduce population growth.

30. The U.S. Population Is Growing Rapidly The US population grew from 76 million in 1900 to 310 million in 2010. Period of high birth rates between 1946 and 1964 is known as the baby boom. The US Census Bureau projects that the United States population is likely to increase to 423 million by 2050. Each addition to the U.S. population has an enormous environmental impact.

31. The United States: A Nation of Immigrants Historically, the United States has admitted more immigrants than all other countries combined. 60% of the U.S. population supports limiting legal immigration. A recent study suggests that to maintain a viable workforce as baby boomers retire, the U.S. would have to absorb many more immigrants per year than it currently does.

32. The American Baby Boom Changes in the distribution of a country’s age groups have long lasting economic and social impacts. Ex: the “baby boom” generation in the U.S. Such a group can dominate the population’s demands for goods and services as well as influence elections and legislation and economic demand. The graying of America may create economic problems for future generations.

33. Slowing Population Growth in India Efforts to limit population growth have not been especially successful because poor couples believe they need several children for work and care. India is currently undergoing tremendous population growth that will likely continue. This may increase the ecological footprint of the nation, but may also serve to hasten the demographic transition.