Key Issue # 2: Where has the world's population increased?

Answer:
Almost all of the world's natural increase is concentrated in the relatively poor countries.

Summary:
Population increases rapidly in places where many more people are born than die. It increases slowly in places where the number of births exceeds the number of deaths. It declines when the number of deaths outnumbers births.

Natural Increase:
Geographers measure population change as a whole through crude birth rate, and natural increase rate. Crude birth rate is the total number of live births in a year for every 1,000 people alive. Crude death rate is the number of deaths in a year for every 1,00 people alive. Natural increase rate is the percent by which a population grows in a year. Very small changes in the NIR dramatically affect the size of the population. The rate of NI affects the doubling time, which is the number of years needed to double a population with a constant rate of NI.

Crude Birth Rate

Crude Death Rate

Fertility:
Geographers also use the total fertility rate to measure the number of births in a society. The TFR is the average number of children a women will have. The TFR for the world is 2.7. In LDC's, it may exceed 6 while in MDC's, it may be 2 or less.

Mortality:
Two measures of mortality in addition to the CDR include the infant mortality rate and life expectancy. The infant mortality rate is the annual number of deaths of infants under 1 year of age compared to the total live births. Poorer countries have higher rates while wealthier countries have the lowest rates. In general, the IMR reflects a country's health-care system. Life expectancy at birth measures the average number of years a newborn can expect to live. NI, CBR, TFR, IMR, and LE all follow similar patterns. MDC's have lower rates of NI, CBR, TFR, IMR, and a higher life expectancy. LDC's have higher NI, CBR, TFR, IMR, and a lower life expectancy.

Article:
http://www.eoearth.org/article/Human_population_explosion

This article explains through many charts and graphics that the world population is increasing in less developed countries more than in more developed countries. Most LDC's are in stage 2 of the demographic transition, therefore they have rapidly declining death rates and very high birth rates. This leads to a ripidly growing population in these regions.