Population Dynamics- Past, Present and Future
- The world's population only grew to two billion in1930
- By 2011 it reached nearly seven billion
- The global growth rate peaked in the 1980s with over 80 million added each year
- It is predicted that by the 1940s the average increase in global population will be down to 30 million a year.
- DONT FORGET- the population is still growing even though the rate of growth may slow down.
Global population changes due to birth and death rates:
- Birth rate: is the number of children born per 1000 of the population in a year
- Death rate: is the number of people who die per 1000 of the population in a year
The natural increase of a population is the difference between the birth and death rates.
Example: if the birth rate is 40 per thousand and the death rate is 20 per thousand, the population is increasing at 20 per thousand or 2% every year.
The change in population should also include the migration rate (the number of people entering and leaving the country)
Ways of measuring Population:
- Life expectency: the average age at which people die
- Infant Mortality: the number of children under the age of one year who die per 1000 births in a year
- Fertility Rate: the number of children that women have in their life time. (Fewer than two means the population will eventually fall)
The study of population is known as demography. So if a question asks for 'demographic changes', these are changes in population.
Fertility rates are high in Africa. But infant mortality is high and life expectancy is low because of poor sanitation, diet and disease.
Fertility rates are low in many european countries due to economic uncertainty. In some countries the death rate has increased because the population is getting older because of rising health problems- alcohol, drugs and tobacco.