• dams for clean water;
• vitamins for pregnant women;
• hand-washing for midwives;
• oral rehydration salts for babies;
• vaccines;
• antibiotics.

2. List at least two factors that has contributed to the reduction in world population estimates from 12 billions down to 9 billions by year 2050?

In essence the 3 billion individuals were never born (relative to prediction) because of there were never conceived at the first place. Birth rate dropped around the world in essence because women's life improved and the need to give birth the a large number of offspring decreased because:

• improve children survival (see above);
• changing role of women in society from housewife and child bearing and up-bringing responsibilities to pursuing education and entering the work force, which delayed first child birth and limited family size;
• women's gain in controling of their own reproductive rights;
• urbanization makes it less necessary to have large families; kids are very helpful when you live as a farmer in the country side, but in cities kids are not as helpful to the maintenance and growth of a household. 

3. Predict at least two consequences of the fact that population growth in no longer a global issue, but rather a regional issue, with rapidly increasing population in some parts of the world and declining population in others.

Half of the world population growth is taking place in five countries: India, Pakistan, Nigeria, Indonesia, Bangladesh and China. Thus there is high pressure and competition within these countries for natural resources, high demand for food, and a need for economic growth. In contrast aging population in countries where birth rates are now below maintenance level face problems of their own, such as great need for health care, retirement and pension. Thus the disparity in population growth around the globe will result in greater cross-border flow of migrant workers (from "poor" to "rich" countries), cross-border flow of capital (from "rich" to "poor" countries), and cross-border flow of goods and services (in either direction).

4. The “A Greener Globe, May be” article argues that urbanization may help the environment. Explain the pluses and the minuses of having more people living in urban areas on the “global environment".

Most of the greenhouse gases produced in many countries is associated with transportation. Public transportations found in cities (particularly subways and buses) are less environmentally harmful per person transported compared with long-distance driving by a single person in his/her individual vehicle. Also, as argued in "A Greener Globe, Maybe", city dwellers have less direct impact on untrammeled landscape like forest. On the minus side and as argued in the same article, people who were born and raised in cities may not appreciate to the same extent as rural inhabitants the importance of preserving watersheds, agricultural lands and wildlife areas. Thus city dwellers who do not understand how their livelihood depends upon what happens in the broader (rural) world are at risk of not understanding the need to provide for sustainable rural development, the maintenance of pristine natural environment, and for preservation of wildlife habitats for example.       

5. What are the advantages and disadvantages of letting “young” people from “poor” countries emigrate to “older and richer” countries to fill in the increasing gap in the labor force?

One advantage of such policy is the mutually beneficial relation between employers of rich countries seeking a population of laborer willing to take relatively low paying jobs. This situation is particularly relevant for the construction, tourism, and food services industries. Many migrant sent a good portion of their salaries to family members "back home".  These remittances, as they are called, can contribute substantially to economic welfare among family members who did not migrate. One disadvantage of this system is the social pressure it creates a class of "second-class" or even better "invisible-second-class" individuals who are vulnerable to abuse, injustice and lack opportunity for advancement (especially if migration is taking place in flagrant disregard for the law).    

6. Explain how the increase living standards for women throughout the 20th century has contributed indirectly to the increase in life expectancy in "developed" nations.

See some of the bullet points of question 1 above. Women's gains in education have translated into economic independence and more control over their reproductive rights. They are having children by choice rather than by necessity or by "tradition."  All together these factors have caused a substantial decrease in infant and child mortality all over the world (although the "crusade" goes on in many parts of the world). 

7. Dr. Ehrlich (professor of population studies and biology at Stanford) argues that the "optimal" population size is two billion. In what ways would a 2 billion world population be more "sustainable" than the current 7 billion?

As indicated in the reading, the future of the sustainability of our planet depends more on the behavior of individuals rather than the sheer number of humans living at a given time. It would be interesting to explore assumptions made by Dr. Ehrlich to determine that 2 billion is about as much human beings the planet can sustain sustainably.  What level of lifestyle did he used as a "reference point"?