NAME:______
Demographics Facts of Life: Doubling Time
Birth and death rates determine the rate of population growth. If the birth and death rates are similar, a population experiences little or no growth. However, when the birth rate far exceeds the death rate, the population soars. These rates are expressed as the number of births for every 1,000 people in a given year. For instance, in 1998 the world’s birth rate was 23 per 1,000 and the death rate was 9 per 1,000. Using the formulas below, we can determine the world’s annual growth rate and number of years it will take the population to double if the growth rate remains constant.
1. % annual natural increase = (Birth Rate-Death Rate)/10
Example: % annual natural increase (1998) = (23-9)/10 = 1.4%
2. Doubling Time (in Years) = 70/% annual natural rate of increase
Example: Doubling Time = 70/1.4% = 50 Years
Directions: Fill in the table below and answer the questions that follow.
Country / Birth Rate in 1998 (per 1000 people) / Death Rate in 1998 (per 1000 people) / % Annual Natural Increase / Doubling Time (in years)China / 17 / 7
India / 29 / 10
Iraq / 38 / 10
Italy / 9 / 9
Japan / 10 / 7
Kenya / 38 / 12
Mexico / 27 / 5
Russia / 9 / 14
South Africa / 27 / 12
United Kingdom / 13 / 11
United States / 15 / 9
Discussion Questions:
1. What figures differ most greatly between countries, the birth rates or death rates?
2. Which three countries are doubling the fastest?
3. How are these countries similar? (in beliefs, technology, medical supplies etc.)
4. Which three countries are doubling the slowest?
5. How are these countries similar? (in beliefs, technology, medical supplies etc.)
6. Use your answers for questions 1-4 to explain why you think some countries are doubling much more rapidly than others?
7. What do you think has allowed some countries, such as Italy to reach almost zero or negative population growth?
8. If you were a national leader in Italy, would you be concerned that your country has reached zero population growth? Why or why not?
9. The population in the US is actually growing faster than its rate of natural increase. Where is the addition population growth coming from?
Demographic Facts of Life: Devastating Tragedies NAME:______
Below is a listing of some of the world’s worst disasters, along with an approximate death toll. At today’s present growth rate, determine how many days, weeks, or months (depending on which time frame is the most appropriate) it would take to replace those lost. Round off to whole numbers. Currently, we are adding 84 million people (net growth)to the world each year or 229,000 people each day.
______People/Year ______People/Day ______People/Hour
Past Disasters (some) / Approximate # of Deaths / The present world population growth will replace this # in ______(days, weeks years).All U.S. Accidental Deaths (1995) / 93,300
Bangladeshi Cyclone / 140,000
Great Flow, Hwang Ho River / 900,000
Total U.S. Automobile Deaths through 1995 / 2,600,000
India Famine / 3,000,000
Total AIDs Death Toll through 1996 / 6,400,000
China Famine / 9,500,000
Use the space below to show your work:
a. All U.S. Accidental Deaths (1995)
b. Bangladeshi Cyclone
c. Great Flow, Hwang Ho River
d. Total U.S. Automobile Deaths through 1995
e. India Famine
f. Total AIDs Death Toll through 1996
g. China Famine
h. Overall, what conclusion can you draw from the table above?