1. 6.9 billion; 310 million (see http://www.census.gov/main/www/popclock.html for latest figures).

2. 1.15% (see http://www.census.gov/cgi-bin/ipc/pcwe for world vital events. Take annual natural increase divided by world population to calculate % annual growth).

3. Types of population growth

• Linear: the population increases by some fixed amount (e.g., 1000) each year ( / curve).
• Exponential: the population increases by some percentage (e.g., 10%) each year (J curve).
• Logistic: as the population increases beyond some point, the rate of population growth progressively slows to 0 (S curve).

4. Biotic potential: the maximum possible growth rate of a population.
Environmental resistance: internal and external factors that operate on a population to reduce the actual growth rate of the population to below the population's biotic potential.

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

6. The amount of time it takes a population to double in size = 70 divided by the population's percentage growth rate.
A population with a growth rate of 10% takes 7 years (70/10) to double in size and 14 years to quadruple (70/10 times 2).

7. 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.

8. Cultural carrying capacity is the maximum number of people an area can support forever at a given standard of living.

9. See http://www.census.gov/ipc/www/idbsum.html for current data by country. For example, compare U.S. to Afghanistan. In general MDCs have lower birth rates, lower death rates, lower total fertility rate, lower infant death rate, higher annual rate of growth, and higher life expectancy. LDCs tend to have more pyramidal age structures (higher percentage of the population below reproductive age thus more future growth potential and momentum).

10. 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).

11. crude birth rate and death rate: number of births and deaths per 1000 population.
total fertility rate: average number of children a woman will have in her lifetime
replacement level fertility rate: average number of kids a couple must have to replace themselves

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

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

14. 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.