1. World Population Dynamics

2. The Population Explosion

3. The Population Explosion

4. Population Explosion—a recent event
Last 200 years or less for MDCs
Industrial Revolution
Improvement in sanitation and medicine
Last 50 years or less for LDCs
Transfer of technology, i.e. medical, agricultural (Green Revolution)

5. Frequency of Vital Events: The Population Clock
Vital Events (per time unit)
The global population reached 6 billion in fall of 1999
The global population is reached 7 billion in October 2011
billion

6. Rates of Global Pop. Change use: International Data Base http://www
Rates of Global Pop. Change use: International Data Base then Online Demographic Aggregation
CBR (crude birth rate) = number of births per 1000 population
1990: 24 Today: 19.4
CDR (crude death rate) = number of deaths per 1000 population
1990: 9 Today: 7.89
growth rate = birth rate - death rate (often in %)
1990: 1.5% Today: 1.2%
growth rates have come down

7. Special Kinds of Fertility and Mortality Rates
TFR (total fertility rate) =
number of children born to a woman during her reproductive years (or life time)
1990: : 2.36
IMR (infant mortality rate) =
infant deaths per 1000 live births (infant < 1 yr)
1990: : (1900: 200)

8. Population, population change, growth rates
Population: number of persons
Population change: increase in the number of persons (per year)
Growth rates: rate of change (per year)

12. Doubling Time
Number of years in which a population reaches twice its size
doubling time can be approximated using growth rates
doubling time = 69 : growth rate
rate: 1.4 doubling time: 49
rate: 2.0 doubling time: 34.5
rate: 0.5 doubling time: 138
rate: -0.5 doubling time: ????

13. Population Pyramids Graphic device: bar graph
shows the age and gender composition of a region
horizontal axis: gender
male: left-hand female: right-hand
absolute number of people or %
vertical axis: age
5-year or 10-year age groups

14. The Demographic Transition

15. Five Stages of the Demographic Transition
birth rates, death rates and growth rates systematically change through time as societies change:
modernize, urbanize
gain access to technology

16. Stage 1
high birth rates, high (at time erratic) death rates, low growth rates
stage for much of human history, traditional societies
practically no country today

17. Stage 2 high birth rates, declining death rates, rising growth rates
improvements in sanitation (water) and medicine
in Europe during Industrial Revolution
in developing countries since the 50s/60s
much of Africa today, some countries of Asia (Afghanistan, Nepal, etc.)

18. Stage 3
continued decline of death rates, declining birth rates, growth rates decline from high to lower levels
change in behavior: adaptation to lower death rate, in particular infant mortality rate
economic change: urbanization (incentive to have fewer children)
Mexico today

19. Stage 4 & 5
Stage 4: low birth rates, low death rates, low growth rates
United States today
Stage 5: low birth rates, rising death rates, declining growth rates (if birth rates drop below death rates: negative growth rates)
Western Europe, Japan

20. Population Pyramid with young cohorts

21. Population Pyramids Population Pyramids on the Web

22. Population Pyramids and Demographic Stages
characteristics shapes of ‘pyramids’
wide base (true pyramid)
wide middle (bulge), somewhat wider base
urn- or bottle-shaped
reversed pyramid
different shapes--different dynamics

23. Population Pyramid and Demographic Transition
Stage 2: wide base

24. Population Pyramid and Demographic Transition
stage 3: wide middle

25. Population Pyramid and Demographic Transition
stage 4: slender

26. Population Pyramid and Demographic Transition
stage 5: narrow base

27. Demographic Transitions in China

30. China Population Pyramid 2005

33. Why does this matter?

34. Why does this matter?
In 1900, Europe accounted for 20 percent of the world's population. Today, this figure is down to 12 percent. By 2050 it will drop to 7, by the end of the 21st century to 4 percent.
Today, India and China together account for 37 % of the world’s population.

35. Population and Energy
China: : 8 % of Global oil consumption but 27 % of growth in global consumption.
World’s second largest consumer and third largest producer of primary energy. Meets 90% of needs with domestic supplies, mostly coal.
India: World’s 5th largest consumer. By 2030 expected to become 3rd largest, overtaking Japan and Russia.
India has only 0.4 % of the world’s proven oil reserves and is expected to run out of coal