1. Human Population : AP Environmental Science

2. Human Population Dynamics There are just three sources of change in population size: 1.Fertility 2.Mortality A."natural decrease" refers to population decline resulting from more deaths than births 3.Migration –Net migration is the number of immigrants minus emigrants

3. Rates of Global Pop. Change Rates of Global Pop. Change use: International Data Base http://www.census.gov/ipc/www/idbnew.html, then Online Demographic Aggregationhttp://www.census.gov/ipc/www/idbnew.html CBR (crude birth rate) = # births / 1000 population per year 1990: 24now: 20.6 CDR (crude death rate) = # deaths / 1000 population per year 1990: 9now: 8.8 Growth Rate = (b + i) – (d + e) 1990: 1.5%now: 1.19% –growth rates have come down

4. Focus: What parts of the world have the highest birth rates? Why do you think that is?

5. Focus: What parts of the world have the highest death rates? Why do you think that is?

6. Human Population Dynamics Total fertility rate (TFR) –The average number of children born to a woman –Average in developed countries = 1.5 –Average in developing countries = 3.8 –Worldwide 1990: 3.1now: 2.76 Replacement fertility rate (RFR) –The number of children a couple must have to replace themselves –A TFR of 2.1 for developed countries with low infant and child mortality rates –Africa RFR = 2.5

7. Focus: What parts of the world have the highest birth rates? Why do you think that is?

8. Human Population Dynamics infant mortality rate IMR infant deaths per 1000 live births (infant < 1 yr) –1990: 62now: 52.4 (normal in 1900: 200)

9. http://www.povertymap.net/pub/mipwa/sections/w-global/health-sanit/infant-mortality- 2.htm Focus: Why are infant mortality rates highest in Africa?

10. www.tte-online.com/.../table-of-contents/ chem-enc-1.html Life Expectancy: the average period that a person may expect to live

11. Migration Net migration is the number of immigrants minus emigrants Immigrants: move into a new country Emigrants: move out of a country Helpful Hint: “I” in immigrants stands for “into” a country; “E” in “emigrants” stands for “exit” a country

13. Overall, the world population is growing at a rate of about 1.7 per cent; if this rate continues, the population will double in 42 years. But, the growth rate is decreasing Focus: What factors are helping the growth rate decrease?