1. HUMAN POPULATION DYNAMICS

2. Is the World Overpopulated? Much of the world’s population growth occurs in developing countries like China and India. The world’s population is projected to increase from 7 billion to 10.8 billion by 2050. Fig. 6-1, p. 125

3. Five Most Populous Countries, 2010 and 2050 Fig. 6-4, p. 127

4. 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. Constant debate over the need to reduce population growth. Must consider moral, religious, and personal freedom. Do not know how long we can continue increasing the earth’s carrying capacity for humans. Likely to be between 7.8-10.8 billion people on earth by 2050. 97% of growth in developing countries living in acute poverty.

5. Features of Populations Populations are dynamic and exhibit attributes that are not shown by the individuals themselves. These attributes can be measured or calculated and include: Population size: the total number of organisms in the population. Population density: the number of organisms per unit area. Population distribution: the location of individuals within a specific area.

6. Features of Populations Population composition provides information relevant to the dynamics of the population, i.e. whether the population is increasing or declining. Information on population composition (or structure) includes: Sex ratios: the number of organisms of each sex. Fecundity (fertility): the reproductive capacity of the females. Age structure: the number of organisms of different ages.

7. Population Dynamics ‣ The study of changes in the size and composition of populations, and the factors influencing these changes, is population dynamics. ‣ Key factors for study include: Population growth rate: the change in the total population size per unit time. Natality (birth rate): the number of individuals born per unit time. Mortality (death rate): the number of individuals dying per unit time. Migration: the number moving into or out of the population. Population size is influenced by births… …and deaths

8. Demography Demography is the study of human populations, their characteristics and changes. Demographics will measure: Statistics about people, such as births, deaths, and where they live as well as total population size.

9. Science Focus: Projecting Population Change Why range of 7.8-10.8 billion for 2050? Demographers must: 1. Measure statistics about people, such as birth, deaths, and where they live as well as total population size. 2. Determine reliability of current estimates 3. Make assumptions about fertility trends 4. Deal with different databases and sets of assumptions

10. The world population, now over 7.1 billion, is growing at the rate of about 80 million per year. Projections put the world population at between 8 and 12 billion in 2050, with nearly all of this growth expected in the developing world. Developing countries include: Africa, Asia, Latin America, the Caribbean, and regions of Melanesia, Micronesia, and Polynesia. 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. Human Population Growth Developed countries grew at 0.1% Developing countries grew at 1.5% (15 times faster)

11. Demographic Transitions Process where countries become economically developed then their birth and death rates begin to decline. In the past this was referred to as “first” and “third” world countries or “developed” and “developing”. Currently this process is described by the different stages according to population growth: Preindustrial stage shows little population growth due to high birth rate with high death rate. Transitional stage is where industrialization begins, death rates drops and birth rates remain high. Rapid population growth occurs. Industrial stage is birth rate dropping and approaching death rate. Population growth slowly declines. Postindustrial stage are birth rate and death rate become similar and population growth slows or declines.

12. Demographic Transition Generalized model of demographic transition shows that the total fertility of a society decreases as the society progresses through the demographic transition. Some developing countries may have difficulty making the demographic transition.

13. ‣ Age structure refers to the number of organisms of different ages. Populations can be broadly grouped into those individuals of: pre-reproductive age reproductive age post reproductive age Analysis of the age structure of populations can assist in their management because it can indicate where most population mortality occurs and whether or not reproductive individuals are being replaced. Age Structure Size/age classes in fish

14. Human Age Structure Human age structure varies from country to country. Number of people younger than age 15 is the major factor determining a country’s population growth. In developing countries age structure tends to be in favor of younger individuals with a large proportion being under 15 years. In developed nations, age structure is relatively even throughout the age groups. Age Structure in Human Populations Changes in distribution of a country’s age groups have long- lasting economic and social impacts.

15. Determining Population Growth The rate at which a population grows or declines depends on its age structure. Age structure diagrams show the distribution of different age groups. These groups are further broken into cohorts: Prereproductive age (0-14) are persons who are not mature enough to reproduce Reproductive age (15-44)are those persons that are capable of reproduction. Postreproductive age (45+) are those persons too old to reproduce.

16. Age Structure Diagrams: Histograms

17. Age Structure Since age structure diagrams are broken down by age, demographers can obtain: Birth rate Maturity rate Death rate of an entire population. These diagrams are usually broken down by country and divided into genders. 29% of the people in developing countries were under 15 years old in 2012 versus only 16% in developed countries.

18. Age Structure: United States Because of baby boom, the US has a bulge(yellow) in the pyramid with people in their 50’s-60’s. There are more women than men in the older group because of differences in longevity between sexes.

19. Rapid Growth Diagram ‣ Pyramid shaped histograms have a birth rate that exceeds the death rate. Lower cohorts have more males and females. ‣ Population growth is rapid in countries that have a pyramid shape. Current modern examples include Africa, Asia, and Latin America

20. Slow/Stable Growth Diagrams ‣ When the histogram shape is “box”-like, then stable or slow growth is represented. ‣ Birth rate is almost equal to death rate. Sometimes called Zero growth. Current examples of slow growth: USA, Australia, & Canada Current examples of stable growth: Denmark, Austria, & Italy

21. Negative Growth Diagrams ‣ If there is declining or negative growth, then the birth rate with be less than the death rate. ‣ Pyramids with declining populations tend to show larger numbers of older persons in their population. Current examples: Germany & Japan

22. Slow decline manageable Rapid decline causes severe economic and social problems. How do we pay for services for elderly? Fig. 6-15, p. 138 Some Problems 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

23. Developing vs. Developed Developing (Transitional, Third World): Higher infant mortality rate because of a shortage in prenatal and pediatric care. Thus, they have more children to ensure some survive. Agricultural societies need children to help in the labor force. Lower per capita income or poorer countries need children to provide an income and sometimes contraceptives are not affordable. Women lack education and job opportunities. Developed (Industrial, First World): Usually don’t have population problems but can be linked to poverty. Educated and working women tend to delay childbearing. Pension systems support people as they age. Family planning and the ability to control fertility. Higher cost of raising children causes people to have smaller families. Abortion is legal.

24. Where Population Growth Occurred, 1950-2010 Fig. 6-3, p. 123

25. Mortality and Fertility Infant mortality rate: The number of child and/or infant deaths. If a mother lives in an area with a high infant mortality rate she will tend to have a lot of children to ensure some will make it to adulthood. This ensures care for aging parents and a labor force. Infant mortality rate is higher in developing countries than in developed countries. Along with life expectancy, the infant mortality rate is a good indicator of the quality of life of a country Replacement-level fertility: the number of children a couple must bear to replace themselves. Slightly higher than two children per couple. (2.1 in developed countries and 2.5 in some developing countries.)

26. Total Fertility Rates Fertility rate – number of children born to a woman during her lifetime. Total fertility rate (TFR): the average number of children a woman has during reproductive years. In 2012, the average global Total Fertility Rate was 2.4 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). If fertility rate drops to replacement level fertility but the population continues to grow, this is called population momentum and can be seen in pyramid shaped age structure diagrams. Birth rates and fertility rates have been slowed or decreased because: Cultural/religious practices prohibited birth control. Cultural/religious practices favored large families. Education/Employment/Status of women is low

27. 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. Child care Marriage age. Religious beliefs, politics, and cultural norms Availability of contraception and abortion.

28. Factors Affecting Death Rates Death rates have declined because of: Increased food supplies, better nutrition due to Green Revolution Advances in medicine. (Antibiotics and vaccines) Improvement in prenatal or neonatal care Improved sanitation, safer water supplies and personal hygiene due to Industrial Revolution. U.S. infant mortality is higher than it could be (ranked 49 th world-wide by CIA and 30 th by Save the Childeren) due to: Inadequate pre- and post-natal care for poor. Drug addiction. High teenage birth rate. More children live past childbirth Fertilizers and pesticides increased crop yields

29. Fig. 6-10, p. 129 Infant Mortality Rates, 1950-2010

30. Populations Can Decline from a Rising Death Rate: The AIDS Tragedy 30 million killed: 1981-2012 Many young adults die: loss of most productive workers Sharp drop in life expectancy International community Reduce the spread of HIV through education and health care Financial assistance and volunteers Fig. 6-15, p. 134

31. Demographics in the USA The baby bust that followed the baby boom was largely due to delayed marriage, contraception, and abortion. Now becoming senior citizens (Graying of America) In 2012, the total fertility rate in the United States was slightly > 2.0

32. Demographics in the USA Nearly 2.3 million people were added to the U.S. in 2012: 70% occurred because of births outnumbering deaths 30% came from illegal and legal immigration. Population increase in recent years has been because of immigration TFR in U.S. dropped Rate of population growth has slowed. Current US Population: 320,367,731

33. Fig. 6-11, p. 135 Legal Immigration to the U.S. between 1820 and 2006

34. Fig. 6-7, p. 132 20 th Century Lifestyle Changes in the U.S.

35. Developed Countries High rates of resource use because of the availability of resources, production, and waste. Result in high levels of pollution and environmental degradation per person because of control methods, clean up, and education. The measure of a country’s economic growth is the Gross National Product (GNP) or the Gross Domestic Product (GDP). The Human Development Index is also commonly used to determine development. Most developed countries have a GDP that is high and a population growth rate that is low.

36. Developing Countries China, the largest, has taken drastic population control methods. By 2050, India is predicted to pass China. Pakistan is projected to become 3 rd (the US is 3 rd now.) Russia is losing 600,000 people a year, after being the 4 th largest country in 1950 due to pollution, crime, corruption, hyperinflation, disease, and despair. Environmentalists are concerned about resource use because developing countries are increasing their standard of living.

37. ‣ India has tried population control methods with modest success. Poor planning, bureaucratic inefficiency, low status of women and lack of support have led to low success. The family planning method calls for: Education of women including basic literacy. Encouraged education of contraception use among women & birth spacing. ‣ Possible problems include: Cultural/Social issues. Cost of programs. India’s Population Control

38. ‣ China has used a government-enforced program, “One-Child Policy”, to reduce the fertility rate. The One-Child Policy includes: Paid leave to women for fertility operations. Monthly Subsidy to one-child families. Tuition and job priorities for only children. Housing preferences. Additional food rations. Monetary compensation. ‣ Problems include: Preference toward gender Increase in orphans Consequences or punishment for multiple births China’s Population Control

39. Core Case Study: Slowing Population Growth in China: A Success Story 1.35 billion people Currently, China’s TFR is 1.5 children per women. China has moved 300 million people out of poverty. China’s policy penalizes couples who have more than one or two children by: Raising their taxes, charging other fees, eliminating income tax deductions for a couple’s third child, and loss of health-care benefits, food allotments and job options

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

41. 1994 Global (Cairo) Conference: Population & Development The summit at Cairo, Egypt, encouraged action to stabilized the world’s population at 7.8 billion by 2050, instead of the projected 11-12.5 billion. Provide universal access to family-planning services Improve the health care of infants, children & pregnant women and improve the status of women by expanding education & job opportunities Encourage development of national population policies Increase men’s involvement in child-rearing responsibility & family planning and increase access to education for girls Take steps to eradicate poverty

42. INFLUENCING POPULATION SIZE The best way to slow population growth is: Investing in family planning(has reduced number of births and abortions throughout world). Reducing poverty. Education Elevating the status of women by not suppressing their human rights and having paying job outside of home. Family planning in less-developed countries Responsible for a 55% drop in TFRs Financial benefits: money spent on family planning saves far more in health, education costs

43. Global Contraceptive Usage Two problems 1. 42% pregnancies unplanned, 26% end with abortion 2. Many couples do not have access to family planning

44. Problems with a Growing Population Reasons for World Hunger Issues Unequal distribution of available food Loss of arable land Increasing population growth rate Increasing poverty in developing countries Strategies for ensuring adequate nutrition for a growing population: Increase the number of new food crops from a diversity of plant species Distribute food more equitably Increase land are that is dedicated to grain production rather than meat production Assist developing countries in efficient crop irrigation systems.

45. Environmental Impact Deforestation destroys habitats and reduces biodiversity: Farming and the creation of monocultures, housing or development projects that cause urbanization, fuel from wood, and fossil fuel recovery from mining. Fossil fuel burning releases CO 2 : Results in climate change, change in temperature and precipitation patterns changing habitats. Intensive fishing and fish farming: Spreads disease to native fish and causes unsustainable fish populations. Diversion and damming of water: For agricultural, municipal, and industrial use reduces water supplies. Building landfills: To accommodate increased amounts of trash.