1. Distribution of World Population Growth
Increases and Decreases
Natural Increase
Fertility
Mortality
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12. Fig. 2-7: The natural increase rate (NIR) is the percentage growth or decline in the
population of a country per year (not including net migration). Countries in
Africa and Southwest Asia have the highest current rates, while Russia and
some European countries have negative rates.
13. Fig. 2-8: The crude birth rate (CBR) is the total number of births in a country per 1000
population per year. The lowest rates are in Europe, and the highest rates are in
Africa and several Asian countries.
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15.
16. World Population Growth
1950 - 2005
Fig. 2-6: Total world population increased from 2.5 to over 6 billion in slightly over 50
years. The natural increase rate peaked in the early 1960s and has declined
since, but the number of people added each year did not peak until 1990.
17. Rates of Natural Increase
Crude Birth Rate (CBR)- Total # of live births per
year for every 1,000 people alive
CBR of 20 means that for every 1,000 people, 20 are
born over a one year period
Crude Death Rate (CDR)- Total # of deaths a year
for every 1,000 people alive
Natural Increase Rate (NIR) is the % by which a
population grows in a year
Subtract CDR% from CBR%
Population may still be increasing despite a decreasing
NIR
Does not take into account migration into a
18. Practice:
Country A
CBR of 45/1,000
CDR of 21/1,000
%NIR?
Country B
CBR of 13/1,000
CDR of 23/1,000
%NIR?
2.4% -1%
19. Natural Increase Rates
Fig. 2-7: The natural increase rate (NIR) is the percentage growth or decline in the
population of a country per year (not including net migration). Countries in
Africa and Southwest Asia have the highest current rates, while Russia and
some European countries have negative rates.
Impact of Small changes on the NIR - even a 1% change is
huge considering the base population (the difference between 1
and 2% could be the difference between adding 66 million or 132
million a year!
Doubling Time- how long it takes for the population to double
If we had continued at 2.2% world pop in 2100 would be 15 billion
20. Source: United Nations Population Division, World Population Prospects, The 2008 Revision.
World Population Growth, 1950–2050
21. Crude Birth Rates and Total Fertility Rates
(TFR)
Fig. 2-8: The crude birth rate (CBR) is the total number of births in a country per 1000
population per year. The lowest rates are in Europe, and the highest rates are in
Africa and several Asian countries.
Total fertility rate (TFR) refers to
the average number of children a
woman will have throughout her
child bearing years (15-49)
22. Infant Mortality Rates
Fig. 2-10: The infant mortality rate is the number of infant deaths per 1000 live births per
year. The highest infant mortality rates are found in some of the poorest
countries of Africa and Asia.
Infant mortality rate (IMR) is the annual
number of deaths of infants under 1 year of
age per 1,000 live births
23. Life Expectancy at birth
Fig. 2-11: Life expectancy at birth is the average number of years a newborn infant can
expect to live. The highest life expectancies are generally in the wealthiest
countries, and the lowest in the poorest countries.
World Life
Expectancies
Life Expectancy at birth measures the
average number of years a newborn infant
can expect to live at current mortality levels
24. Crude Death Rates
Fig. 2-12: The crude death rate (CDR) is the total number of deaths in a country per
1000 population per year. Because wealthy countries are in a late stage of
the Demographic Transition, they often have a higher CDR than poorer
countries.
Hinweis der Redaktion
Population
-increases in places where many more people are born than die
-increases slowly in places where the number of births exceeds the number of deaths by only a small margin
-declines in places where death outnumber births
It took over 3,011,800 years for the world to reach its first 1 billion people
- 130 years to add another 1 billion (1800-1930)
-30 years to add another 1 billion (1930-1960)
-App. 15 years to add another 1 billion (1960-1975)
-App. 12 years to add another 1 billion (1975-1987)
- IS beginning to slow overall- about 2.5 million added over the last 10 years (growth rate of about 1.3% which is a slower rate of natural increase than 1950-2000 which was about 2.2%)– about 80 million more each year
Present estimates are for the population to reach 8-12 billion before the end of the 21st century.
Small changes in the NIR% have a large impact – even a 1% change is huge considering the base population
Doubling time – how long it takes for the population to double
If we had continued at 2.2% world pop in 2100 would be 15 billion
100% of increase is in LDCs exceeds 2% in Asia, Africa, Middle East and Latin America but is negative in Europe
Highest crude birth rates are in subsaharan africa lowest in europe
Total fertility rate (TFR) number of births in a society avg # of children per woman
TFR is about 2.6
Recall from yesterday’s lecture the major concentration centers and how they play a larger role in the Natural Increase of the world’s population.
The percentage by which the population grew (NIR) declined during the late 20th century from its historic peak in the 1960s– the number of people added each year did not, however, decline.
Crude – concerned with the whole rather than individuals or groups
CBR - # of live births per year for every 1,000
CDR # of deaths per 1,000
Natural increase = cbr-cdr
Logically, as the pop base increases, the easier it becomes to increase overall pop
Small changes in the NIR% have a large impact – even a 1% change is huge considering the base population (the difference between 1 and 2% could be the difference between adding 66 million or 132 million a year!
Doubling time – how long it takes for the population to double
If we had continued at 2.2% world pop in 2100 would be 15 billion
Almost 100% of the natural increase of the world population is in LDCs
-NIR exceeds 2% in Asia, Africa, Middle East and Latin America but is negative in Europe… many African countries have CBRs over 40 where much of Europe average around 10
-U.S. currently around 1% NIR (1.10% in the 90s, project .5% by 2050)
-Regional differences in the NIRs mean that most of the world’s additional people live in countries that are least able to maintain them
Highest crude birth rates are in Sub-Saharan Africa lowest in Europe
Total fertility rate (TFR) refers to the average number of children will have throughout her child bearing years (15-49)
-TFR attempts to predict the future behavior of individual women depending on the degree of cultural change in a particular society
Infant mortality rate (IMR) is the annual number of deaths of infants under 1 year of age per 1,000 live births
- Highest rates are the poorest countries
-IMR in Africa exceeds 10% - reflects a country’s healthcare system (lowest rates in Western Europe)
- Lower IMRs = better doctors
- US IMR is on the rise as is the maternal death rate – subgroups – African Americans and other minorities (i.e. Mexican/Latin American immigrants) have twice as high IMR – comparable to levels in Latin America and Asia because of lack of equal access to healthcare
Life Expectancy at birth measures the average number of years a newborn infant can expect to live at current mortality levels
-Same regional differences as in other slides (i.e. africa, europe)
CDR does not fluctuate as much as the others. Lowest is 1/1,000 highest 19/1000, also doesn’t follow the usual pattern with many Asian countries having similar rates to the west – look at East Europe – Sub-Saharan Africa
That is because each of these countries are in different stages of the demographic transition (discussed tomorrow!)
