World population has grown exponentially (rapidly). Not only does population increase but the rate of increase becomes greater. Population is now expected to peak in 2150 at 10 million people followed by a period of zero growth or even decrease.
Natural change is the difference between birth rate and death rate. Until recently all countries had been in a state of natural increase (growing population) except for times of epidemic, famine or war. Today some countries birth rates have decreased so much they are in a state of natural decrease where less babies are born than people dying and population is declining.
Birth rate shows a better picture of development than death rate because death rate is generally low in all countries now.
Demographic Transition Model
The model explains birth and death rate patterns across the world. The diagram is divided into 5 stages. It allows us to compare and see what the future may hold for developing countries. When it was first created only 4 stages were needed but as countries in Europe have began to show natural decrease another stage was added.
It simplifies changes in birth and death rates to make patterns clearer and easier to understand.
Each stage shows different changes which you know and should be able to explain why these changes might occur.
1- Rainforest Tribes, 2- Afganistan, 3- Brazil, 4- USA or UK, 5- Germany or Japan
Major factors effecting population growth
Agricultural change- technology improves yields and saves labour freeing a workforce for industry and rapid economic growth.
Urbanisation- people migrate from the rural areas into the cities looking for better job oppotunities or better education for children who can then become skilled workers.
Education- As Education levels increase bringing improved standards of living, children become an economic disadvantage. Fewer children means more money to spend on each one.
Status of women- As economy develops more workers are needed and higher levels of equality lead to woman working outside the home with the men. This leads to smaller families as woman don't want to give up work for too long.
Population pyramids are a type of bar graph used to show the age and gender structure of a population. From a population pyramid you can learn about death rates, birth rates and life expectancy and the stage of the DTM the area is in.
Stage one pyramids are concave and look like more like a pyramid but moving toward stage five the pyramid becomes move convex and doesn't look so much like a pyramid in shape.
You can predict future changes using population pyramids.
You can also see the effects of war in population pyramids. Generally the number of males in an age group will have been reduce and you also can see baby boom where lots of children are born around the same time. e.g the end of WW2.
People move for many different reasons as the result of push-pull factors.
Impacts of migration can be both positive and negative on both the countries of origin and the destination. Migrant workers often sent money home which is an advantage but it disadvantages the host countries.Migration brings labour and skills and often migrant workers will do jobs that UK citizens don't want to do but immigrants can be a burned by using our services such as schools and by wanting housing that UK citizens need.
Within the EU emigration is freely allowed and you can move to any other EU country. Some migration is only temporary like Polish to the UK and most immigrants pay tax so that the host country does not lose out too much. Europe needs immigrants because of falling birth rates.
Refugees are people who have moved because of persecution, war or famine.