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Questions | Answers

1. 7.3 billion; 323 million (see for latest figures).

2. 1.2%

3. Exponential growth

4. Death rates went down due to better sanitation, medicine, nutrition, food production/distribution, but birth rates did not decrease as fast.

5. Definitions:

  • crude birth rate: births per 1000 in the population
  • crude death rate: deaths per 1000 in the population
  • rate of natural increase: the percent change in population size each year = crude birth rate - crude death rate, divide by 1000, multiply by 100.
  • age structure: a pyramid depicting percent (or #) of males and females in each age class.
  • total fertility rate: average number of children a woman has in her lifetime.
  • replacement level fertility rate: average number of children a couple must have to replace themselves.

6. About 2.1 in MDCs and about 2.5 in LDCs; it is higher in LDCs due to higher infant mortality rates.

7. People Overpopulation: Too many people for resources. LDCs that have 80% of the world's population (9 out of 10 children born now are born in LDCs)
Consumption Overpopulation: Too much consumption for resources. MDCs only have 20% of the population but use 80% of mineral and energy resources (and have 80% of the wealth).

8. The amount of time it takes a population to double in size = 70 divided by the population's percentage growth rate.
First figure out how many years it takes the population to double using the formula. Then figure out how many doubles it takes to reach the population of question and multiply the two. Example: A population with a growth rate of 10% takes 7 years (70/10) to double in size and 14 years to quadruple (7 times 2 doubles).

9. The maximum number of individuals an area can support forever. [Note every word is critical to the definition]
When populations exceed the carrying capacity of their environment, they are using up resources faster than they replenish and so are degrading their environment, reducing the carrying capacity, and heading toward a die-off (overshoot-crash phenomenon). Thou shalt not exceed the carrying capacity for long.

10. Cultural carrying capacity is the maximum number of people an area can support forever at a given standard of living. Look at your Ecological Footprint assignment to find out.

11. education, affluence, religious/cultural norms, role of women in society, urbanization, infant mortality rates, retirement system, availability of birth control.

12. They fall into two broad categories: voluntary and involuntary. There can be laws or economic incentives/deterrents. Within a country, migration policies affect population growth.