How and why has population changed?

Global population has changed because of wars, conflict and due to natural desasters.

Population increase - The change of population in a country is the difference between the number of babies born and the number of people who die. If this is a

Population numbers change over time, influenced by births, deaths and migration into or out of the area. Global population levels, having grown slowly for most of human history, are now rising. Births and deaths are natural causes of population change. The difference between the birth rate and the death rate of a country or place is called the natural increase. The natural increase is calculated by subtracting the death rate from the birth rate. 

As populations move through the stages of the model, the gap between birth rate and death rate first widens, then narrows. In stage 1 the two rates are balanced. In stage 2 they diverge, as the death rate falls relative to the birth rate. In stage 3 theyconverge again, as the birth rate falls relative to the death rate. Finally in stage 4 the death and birth rates are balanced again but at a much lower level.

It refers to the transition from high birth and death rates to low birth and death rates as a country develops from a pre-industrial to an industrialized economic system. The demographic graph shows population change over time. It studies how birth rate and death rate affect the total population of a country.

Somalia is a country with a youthful population which means there are more younger people then older people. Somalia has a population of around 10 million. Birth rate - 40.45 births/1,000 population Death rate - 13.62 deaths/1,000 population Net migration - -8.49 migrant(s)/1,000 population 5.99 Fertility rate - children born/woman Child labour -total number: 1,148,265 Life expectancy -total population: 51.96 years.Degree of risk:very high. ACivil war ended a 21-year dictatorship in 1991, and Somalia has been without a national government since that time. UN efforts from 1992 to 1995 to stop clan fighting failed, and UN and U.S. forces left after suffering high casualties.

Italy has an ageing population which means there are more elderly dependants then youthful dependants. Population: total population:82.12 years Net migration rate: 4.1 migrant(s)/1,000 population. Reasons for Italys ageing population: 1) Education for women. 2) Women get jobs. 3) Women get married later so they have less children. 4)The role of women increased. 5) Women have more opportunities. 

Different countries face varying problems when attempting to manage population change. LEDCs have to manage rapid population growth. MEDC shave to manage slow or negative growth and an ageing population.

Causes of population growth in LEDCs Limited access to family planning services and education about contraception. Contraception and other methods of family planning may not be culturally or religiously acceptable.Children are a valuable source of labour and income for a family. They can work on the land from a young age and as they get older they can earn money in other jobs.Children can help to care for younger children and elderly family members.High rates of infant mortality (infant deaths) mean that women need to have many children in order to ensure that some survive through to adulthood.It may be traditional or culturally important to have a large family.

LEDCs have a high population-growth rate which means that they have many young dependants. Governments in LEDCs and international bodies and charities are working to reduce birth rates and slow down rates of population growth.

Population a group of people within an area. Distribution the spatial property of being scattered about over an area or volume. Densely an area with lots of people living in it. Sparsley an area that has a few people living in it. Birth rate number of births in a year per 1,000 population. Death rate number of deaths in a year per 1,000 population. Infant mortality the number of babies out of every thousand that dies before the age of one. Demographics the statistics of a population e.g. age, income, education Demographic transition model the transition of high birth rates and death rates to low birth rates and death rates that occurs as part of the economic development of a country from a pre industrial to a post industrial economy Migration the movement of persons from one country or locality to another Push factors things that make people want to leave an area Pull factors things that encourage a person to an area Immigrant a person who leaves one country to permanently settle in another Migrant a person who leaves his/her country of origin to seek residence in another country. Immigrate when a person leaves there country of origin to settle in another country. Migrate when a person moves from one country to another and settles there. Refugee a person who has been forced to leave his/her home because of fear of persecution Dependency ration the ration of people who defined as dependant (under 15 years old and above 64 years old) Population pyramid a bar graph showing the population divided into males and females in different age groups Census the process of obtaining information from every member of a population Policy  a plan of action adopted by a individual or a social groups Aging population occurs when the average age of a population is getting older Life expectancy the average number of years a person is expected to live Replacement rate the total fertility that exactly balances births and deaths, so the population growth is zero Exponential growth  a change in population that is proportional to the size of the population

People migrate for many different reasons. These reasons can be classified as economic, social, political or environmental: economic migration - moving to find work or follow a particular career path. social migration - moving somewhere for a better quality of life or to be closer to family or friends. political migration - moving to escape political persecution or war. environmental causes of migration include natural disasters such as flooding. Some people choose to migrate, eg someone who moves to another country to enhance their career opportunities. Some people are forced to migrate, eg someone who moves due to war or famine. Push factors are the reasons why people leave an area. They include: lack of services lack of safety high crime crop failure drought flooding poverty war.  Pull factors are the reasons why people move to a particular area. They include:higher employment more wealth better services good climate safer less crime political stability more fertile land lower risk from natural hazards. 

Migration policies

The number of migrants a country receives is influenced by the countries migration policy. Countries such as the UK operate a points based system. People are awarded points depending on their skills, previous income, and age. This has system gives some people visas to allow them entry into the UK for work - especially where there is a shortage of labour in that sector. Migration laws are complex, and change in different countries, even within the EU. Open door - This type of policy allows anyone to come to live in a country. The country will often run campaigns abroad, usually targeting specific groups, to try and encourage people to go and live in that country. For example, there is an open-door policy for migration between EU countries. Quotas - This restricts the number of people allowed into a country per year. The country may decide on different things to restrict, e.g.: total number allowed, a total number from a particular area or a particular type of person. Skills Test - Potential migrants have to pass a 'skills test'. This ensures that all the migrants a country receives are skilled and qualified. It may also involve a points system where you have to have skills in certain areas to get enough points to qualify to be admitted.

Why encourage immigration Tensions

• Can help address underpopulation
• Helps address labour shortages - immigrants often do jobs that native people would rather not do
• Meets specific skills shortages: doctors, teachers, engineers
• Working-aged immigrants pay taxes which help pay for services
• Immigrants add to a country's talent and culture.
• For economical, environmental, sociocultural or political reasons.
• Upon return, migrants bring new skills to the country such as the ability to speak foreign languages.These new skills can help to improve the economy in the country of origin.

• Pressures on housing, health care and education caused by immigration
• Fear by native population that immigrants are 'taking their jobs'.
• Discrimination / abuse of immigrants
• Perception that immigrants take advantage of state benefits
• Can alienate 'native' population
• Quotas or skills tests may cause problems for people who want to bring family to live with them.
• Places will become over crowded. 
• Migrants send money home to their families in 

Drought - In 2000, Ethiopia and Eritrea suffered their most severe drought since 1984. The countries continue to suffer from severe drought conditions, which have drastically increased the number of people relying on food aid, so a lot of people migrated from the countries.

Infectious Disease Outbreak - The cholera epidemic which broke out in August 2008 in Zimbabwe continues today having spread to over 98,000 cases and nearly 5,000 deaths. Because of this a lot of people migrated from the country so they wouldn't get the disease. 

When Poland and seven other Eastern European countries joined the EU in 2004, the UK received many economic migrants. There were 500,000 workers from Eastern Europe in 2009. The pull factors included wages five times greater than they could get at home. Some come for seasonal jobs, such as vegetable and fruit picking. More qualified migrants may look for medical or education jobs. The Eastern European migrants are not evenly spread across the UK