Human Populations

1. Human Populations

2. History of Human Population Early Hunter Gatherers • Nomadic, With a Strong Sense of the Earth • Practiced Intentional Birth Control Rise of Agriculture • Necessary for Survival • Animals became extinct via hunting and altered habitat • Cultivation of own food

3. History of Human Population Cont… Agriculture Gives Rise to Cities • Food Produced in Country, Consumed in City • Less productive soil • Waste of Populations Concentrated in Cities • Population Control in Medieval Societies • Disease • Famine • Wars

4. History of Human Population Cont.. Industrialization • Early Phases: Child labor • Cheap source of income and cheap labor • Exponential growth of populations • By 1900s, Birth Rate in Industrialized World Dropped • Why?

5. Human Population Growth

8. Current World Population Global population ? • The global population grows by: • Nearly 2.3persons per seconds • Nearly 8,343 persons per hour • Over 200,234 persons per day • Over 73 million persons per year

9. Rate of Global Population Changeuse: International Data Base http://www.census.gov/ipc/www/idbnew.html, • CBR (crude birth rate) = # births / 1000 population 1990: 24 now: 20.6 • CDR (crude death rate) = # deaths / 1000 population 1990: 9 now: 8.8 • Growth Rate = (b + i) – (d + e) 1990: 1.5% now: 1.19% • growth rates have come down

10. Crude Birth Rates

11. Crude Death Rates

12. Doubling Time • Doubling Time of a population: • 70/annual percentage growth rate. Doubling time for the Human Population • 800 million in 1700 • 1.6 billion in 1900 • 3.2 billion in 1965 • 6.4 billion in 2005 • J shaped curve

14. LIMITS TO GROWTH • Thomas Malthus-excess population growth is the cause of many social and environmental problems • Disease, famine and population control is only way to stabilize • Karl Marx- oppression and exploitation are the real causes of poverty and environmental degradation • Population growth is a symptom or result of other problems, not the source

15. HUMAN DEMOGRAPHY • Demography - vital statistics about people • 2 demographic worlds • First is poor, young, and rapidly growing. • Less-developed countries contain 80% of world population • Second is wealthy, old, and mostly shrinking. • Western Europe, Japan.

16. Human Population Density

17. Factors affecting birth rates and fertility rates • Age of woman at time of marriage • Availability and affordability of birth control and abortion • Children needed in the workforce • Costs of raising and educating children • Culture, religion, tradition • Government programs • Infant mortality

18. Factors affecting death rates • Availability and affordability of health care, food and better nutrition • Safer water supplies • Improvements in sanitation and pollution control • Improvements in medical and public health

19. Indicators of overall health of people in a country • Life expectancy • Infant mortality rate-number of babies out of every 1000 born who die before age 1

20. Human Population Dynamics 3 sources of change in population size — • Migration • Fertility • Mortality

21. Curbing Population Growth • Family Planning • Reduce births and abortions • reduces children's social services needs • reduces risk of childbearing deaths • Effectiveness depends on program design and funding

22. Rewards and Penalties to Reduce Births • What might work: • Encourage people to have fewer children • Reinforce existing customs and trends toward smaller families • Don’t penalize for already existing larger families • Increase poor family’s economic status

23. Case Study-India • Family planning efforts began in 1952; fertility rate declined from 5.3 to 3.4 but population growth is still exponential • Disappointing results due to: • poor planning • bureaucratic inefficiency • low status of women • extreme poverty • lack of administrative & financial support

24. Curbing Population Growth • Provide economic incentives for having less children • Empower and educate women • Access to education and paying jobs outside home • Society doesn’t suppress women’s rights • Government family planning services • Reduce poverty and economic development

25. Case Study-China • Family planning efforts began in 1970 • Population control program is extensive, intrusive and strict: • postpone childbearing • only one child/family -->benefits • Free education and health care • Increased personal and family incomes • Preferential housing and retirement income • effective because China is dictatorship; limited resources would have mean disaster

26. Age Structure • Bar graph that shows the age and gender composition of a region • horizontal axis: gender • male: left-hand female: right-hand • absolute number of people or % • vertical axis: age • 5-year or 10-year age groups

27. Age Structure

28. 4 Stages of the Demographic Transition • Birth rates, death rates and growth rates change through time as societies change: • modernize, urbanize • gain access to technology

29. Stage 1: Pre-Industrial • High birth rates, high (at time erratic) death rates, low growth rates • Stage for much of human history, traditional societies • Living conditions severe

30. Stage 2: Transitional • High birth rates, declining death rates, rising growth rates • Improvements in sanitation (water) and medicine • Ex. Europe at the start of Industrial Revolution • developing countries since the 50s/60s • much of Africa today, some countries of Asia (Afghanistan, Nepal, etc.)

31. Stage 3: Industrial • Continued decline of death rates, declining birth rates, growth rates decline from high to lower levels • Lower death rate, in particular infant mortality rates • Economic change: urbanization (incentive to have fewer children) • Better jobs • Education for women • Mexico today

32. Stage 4 Post-Industrial • Stage 4: birth rates are less than mortality rates • Zero population growth or declining population growth • Standard of living is high • Ex. Japan, many European countries