# Where has the world’s population increased?

## Presentation on theme: "Where has the world’s population increased?"— Presentation transcript:

Where has the world’s population increased?
Ch. 2 Key Issue 2 Where has the world’s population increased?

Distribution of World Population Growth—How do we measure it?
Natural Increase (NIR) Fertility (CBR and TFR) Mortality (CDR, IMR, and Life Expectancy)

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.

Crude Birth Rate (CBR) The total # of live births in a year for every 1,000 people alive in a society CBR of 20 means that for every 1,000 people in a country, 20 babies are born over a 1 years period.

Crude Birth Rates 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.

Crude Death Rate (CDR) The total # of deaths a year for every 1,000 people alive in a society Annual # of deaths per 1,000

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.

Natural Increase Rate The percentage by which a population grows in a year. CBR-CDR=NIR You have to convert CBR and CDR to percentages CBR 20 and CDR 5 2-.5=1.5NIR

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.

Doubling Time The number of years needed to double a population, assuming a constant NIR If the current NIR continues, the global population would reach 24 BILLION by 2100

Total Fertility Rate (TFR)
Used to measure the number of births in a society It is the average # of children a woman will have throughout her childbearing years (about 15 through 49 yrs) The CBR provides a picture of a society as a whole in a given year TFR attempts to predict the future behavior of individual women

Total Fertility Rates Fig. 2-9: The Total fertility rate (TFR) is the number of children an average woman in a society will have through her childbearing years. The lowest rates are in Europe, and the highest are in Africa and parts of the Middle East.

Infant Mortality Rate (IMR)
The annual # of deaths of infants under 1 year of age, compared with total live births Expressed as the number of deaths among infants per 1,000 births rather then a percentage

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.

Life Expectancy Life expectancy at birth measure the average number of years a newborn infant can expect to live at current mortality levels Most favorable in wealthy countries Late 70s in western Europe Only 40s in most sub-Saharan African countries

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.

ANY PATTERNS? These all have repetitious patterns
More developed countries of the world have lower levels of natural increase, total fertility, and infant mortality, and higher levels of life expectancy Whereas, higher natural increase, crude birth, total fertility, and IMRs, and lower life expectancy are found in less developed countries.