- Created by: foxofr
- Created on: 25-02-15 12:29
Population and resources
Optimist – Plenty of food, the issue is distribution. People are healthy and living longer than before. Efforts should be devoted to helping economies in the south become more like the north.
Pessimist - Neomalthusian – we are all doomed, hunger affects 1 in 7.
Water scarcity and soil degradation – hard to produce food.
20% of people who live in the developed world are to account for 80% of global pollution and resource use.
75 million people added each year with 95% of growth in developing countries.
The worlds changing population since 1950
Different spatial scales give different patterns of change.
Strong positive relationship between population size and time since 1950’s.
Population growth is spatially different.
Africa and the Caribbean have the most rapid population growth.
Europe negative population growth, 1950 21.7% of the world lived in Europe, now only 7%.
1950 world life expectancy was 46, by 2020 – 70.5.
MEDC 1950 – 65.8 2020 – 77.2
LEDC 1950 – 41.1 2020 – 69.5
in 1950 there was a gap of 24 years between MEDC and LEDC, by 1950 the gap is only 7.7, decreased rapidly and overall life expectancy has increased.
Fertility and mortality
Significant fertility rate = 2.1 this is too maintain population. Replacement level = 2.1
World fertility rate 1950 – 4.9 2020 – 2.4
Huge variation between MEDC fertility rate and LEDC fertility rate.
MEDC 1950 – 2.8 2020 - 2.4
LEDC 1950 – 6.1 2020 – 2.4
Large spatial variations between MEDC and LEDCs.
MEDC fertility rate decreased until 1980 from 2.8 to 2.0 after which there was no change until 2010 where rose to 2.1 is.
LEDC fertility rate began declining in 1970 from 6.1 to 2.4 in 2020.
Rate of increase in births is expected to be less than the rate of decrease in death between 1980 and 2020. Large number of persons born in previous years is getting older and the number of children in future years is not expected to increase as rapidly. Trend causes the median age in MEDC to increase from 28 in 1950 to 38 in 2020.
Total fertility rate – the average number of children that would be born to a woman over her lifetime if she experienced the exact current age specific fertility rates and she survived from birth to the end of her reproductive life.
Infant mortality rate – the death of a child less than 1 year old, is the number of deaths of the children/1000 live births.
Age specific mortality – total number of deaths/yr./1000 people of a given age
Child birth rate – Gives the average number of births during a year/1000 people in the population midyear.
Natural population change – Difference between birth rate and death rate of a country
Doubling time – Period of time required for a quantity to double in size or value
Dependency ratio – The number of dependents aged 0-14 and over 64 to the population aged 15-64