270 likes | 280 Vues
Learning Outcomes. CHAPTER 2 Population. You Will Learn : to describe the change in world population to describe the distribution and density of world population to explain the causes, consequences and responses to high and low rates of population growth.
E N D
Learning Outcomes CHAPTER 2Population You Will Learn: • to describe the change in world population • to describe the distribution and density of world population • to explain the causes, consequences and responses to high and low rates of population growth
Lead-in: Living in a Crowded World (Suggested Answers) The cartoon shows that the world population is increasing at a rapid rate. The cartoonist is probably trying to depict a pessimistic picture of the growing world population. He is trying to bring across the point that the world population is growing too rapidly and the earth might not be able to sustain such population increases due to increased demands on its natural resources.
Lead-in: Living in a Crowded World Extension Activity: Living in a Crowded City For years, major cities around the world have been facing increasing population growth. For instance, Tokyo city has a population of 8 163 573 while the second largest Japanese city Yokohama has a much smaller population of 3 220 331. This has led to overcrowding conditions due to limited space and resources. How are the lifestyles of people living, working and commuting in such cities affected? High-rise buildings are common in land-scarce Tokyo (see picture on right) as compared low-rise shop-houses found in remote Japanese towns and villages (see picture on left).
World Population Growth • Population growth refers to a change in population size. • This change can be positive, negative or none at all. When there is no change in population size, it is known as zero population growth. • A rapid increase in population is called a population explosion. The world population has been increasing at a rapid rate since 1950. The graph shows that population growth in the world has been increasing since 1750.
Factors Affecting World Population Growth Rate • A rise in birth rates and a fall in death rates can effect changes in the world population growth rate. • Birth rate refers to the number of live births per 1000 people per year while death rate refers to the number of deaths per 1000 people per year. • The rate of natural increase will determine the speed of population growth.
Factors Affecting World Population Growth Rate • Today, the world’s population is growing at a rapid rate because the birth rate generally exceeds the death rate. • People are also living longer because of better medical and health care, improvements to hygiene and increases in food supply due to advances in technology. Farmers are using technology to improve the quantity and quality of their produce. Advances in medical science have led to better medical and health care.
Population Distribution • The way in which people are spread out over an area of land is known as the population distribution. • The population distribution of the world is uneven with most of the world’s population concentrated in different parts of Asia, such as China, India and Indonesia (2005).
Factors Influencing Population Distribution Physical environment • People tend to live in areas with fertile soil and where the climate is not extreme. • People do not favour places with climates which are too hot, too cold or too dry because these conditions are not suitable for the cultivation of crops or settlement of human beings. River deltas are usually heavily populated because fertile sediments deposited by the river are favourable for growing crops. Harsh environments such as deserts are not attractive places to stay because of the hot and dry climate.
Factors Influencing Population Distribution Level of technology • Improvements in technology can enable people to convert environments which were previously unsuitable for living into suitable living environments. • For instance, water can be transported to various places through pipes and canals. This has allowed people to live in deserts. Despite Las Vegas’s dry climate, technological advances have allowed the city to support a large population and a vibrant entertainment industry.
Population Density • Population density is the number of people living in a unit area of land. • It is expressed in terms of the number of people per square kilometre of the land. A dense population would have more people per square kilometre compared to a sparse population. • For example, Singapore has a dense population of about 6 000 people per square kilometre, compared to Canada’s population density of 3 people per square kilometre. Total number of people Population density = Total land area
Population Density • People are not evenly distributed in a country and some regions are more crowded than others. • Cities generally have high population densities while areas such as countrysides and deserts usually have low population densities. Countrysides usually have low population densities with few people per square kilometre. Cities have high population densities with high number of people per square kilometre.
High Rate of Population Growth • Less developed countries with low levels of economic wealth and poor living conditions usually experience a high rate of population growth (e.g. countries found in Africa, South America and some parts of Asia). • A population pyramid can be used to show the pattern of population growth. It is a graph that provides information about the number or percentage of people in different age groups, and the proportion of males to females in a place. A triangular-shaped population pyramid with a broad base is characteristic of a country where the population is growing rapidly. There are many more young people than elderly people and few people are expected to live up to 80.
High Rate of Population Growth Causes of a high population growth • There must be a low death rate and a high birth rate to result in a rapid increase of a population. Factors that lead to a low death rate • Better medical and health care can result in improving the survival rate of babies beyond their first year and thus reducing the infant mortality rate. It can also lead to the increase in life expectancy of the elderly. • People are less prone to falling sick and contracting diseases with better hygiene and clean living conditions.
High Rate of Population Growth Factors that lead to a high birth rate • Lack of family planning can result in a couple having many children. This is especially so in less developed countries where people are less educated and aware of family planning methods. • Couples who enter into early marriages can increase the number of childbearing years for the women. This can result in couples having more children.
High Rate of Population Growth Factors that lead to a high birth rate • The preference for sons in some societies (e.g. China and India) has led to couples continuing to have children until they succeed in having sons. • The need for farm labour in less developed countries has resulted in people having large families to provide more hands to work in the fields.
High Rate of Population Growth Consequences of a high rate of population growth • The demand for resources such as food and water increases with more people. Many less developed countries often suffer from the shortage of food due to insufficient production of food. The higher demand for housing has resulted in inadequate housing for growing populations in cities of less developed countries. Squatter settlements and make-shift houses have sprouted around the outskirts of cities of less developed countries due to the lack of proper housing.
High Rate of Population Growth Consequences of a high rate of population growth • There are times when rapid population growth can also lead to intense competition for limited number of jobs. Environmental problems may arise if there is a lack of proper waste disposal services to deal with the waste produced by people. Waste left unattended to can lead to pollution of the environment and the deterioration of living conditions.
High Rate of Population Growth Actions to control a high rate of population growth • Education and the inculcation of proper family planning methods can teach couples to control the size of their families. • Incentives and penalties can be used to control population growth. For instance, tax subsidies may be given to couples who have fewer children while those who have more may be penalised with higher taxes. • China’s ‘One Child Policy’ which was implemented in 1979 used such methods by fining couples who had more than one child while providing education and housing subsidies to those who complied with the policy.
Low Rate of Population Growth • Developed countries with high levels of economic wealth and living conditions usually experience a low rate of population growth (e.g. Japan and the United Kingdom). A beehive-shaped population pyramid is characteristic of a country where the population is growing very slowly. The number of youth and children are decreasing as people are having less children. Many people can expect to live up to 80 or longer.
Low Rate of Population Growth Causes of a low rate of population growth • Countries that experience a low rate of population growth usually experience a low death rate as well as a low birth rate. Factors that lead to a low death rate • People living in countries with high standards of hygiene are less prone to diseases associated with unhygienic living conditions (e.g. cholera). • People living in developed countries have higher levels of income and are able to afford better nutrition and do not suffer from food shortages. • People are able to enjoy longer and healthier lives with better medical and health care.
Low Rate of Population Growth Factors that lead to a low birth rate • Couples who enter into late marriages tend to have fewer children because they are left with fewer years to have babies. • As more people choose to remain single, fewer marriages can result in fewer families and a fall in birth rate. • There is an increasing trend of people in developed countries who prefer to have smaller families. This is attributed to the increase in cost of living and raising children. The difficulties of balancing between work and family life have led to couples preferring to have fewer children.
Low Rate of Population Growth Consequences of a low rate of population growth • Such countries will face an ageing population. The burden on the working population will increase as there are more elderly, and fewer youths joining the workforce. • A shrinking population will result in fewer people in the workforce. This will in turn lead to higher taxes on each working person to fund public amenities and projects. • There will be a smaller talent pool to lead and serve the country. This problem will be further worsened for countries which already have small populations (e.g. Singapore).
Low Rate of Population Growth Actions to manage a low rate of population growth • Encouraging marriage and childbearing can increase birth rates. For instance, the Singapore government gives incentives in the form of tax rebates to couples who have more children. • The needs of an ageing population, which is a consequence of a low rate of population growth, have to be met. These include building special facilities for the elderly and encouraging their families to care for them. • There is an increased need to build special facilities such as specialised hospitals to treat illnesses associated with the elderly and homes catering to the elderly.
Low Rate of Population Growth Actions to manage a low rate of population growth • The elderly need to be kept healthy and active. In Singapore, there are exercise classes and courses for lifelong learning at community centres available. To reduce the burden on the working population to support the elderly, the retirement age can be raised to extend the working life. • There is also a need to encourage financial planning. This is a form of early planning to ensure people have enough financial resources when they retire to meet their life’s goals.
Skills Builder: Suggested Answers The issue in the article describes a fall in the population growth in Japan due to a higher death rate than birth rate. Cause: There is an increase of young people who have decided against starting families and having children. This is because they feel it is a burden to their career and lifestyles.Consequence: This social trend has resulted in a drop in the birth rate and a fall in population growth. If this persists in the long run, there will be an increasing burden on a smaller workforce that would have to support a mass of pensioners. As such, the ageing population would have serious impacts on the economy.
Skills Builder: Suggested Answers Actions taken: The Japanese government has tried to encourage people to have more children by making special arrangements. These include promoting work- life balance by making it easier for parents to take time off work to care for their newborns, and building more day-care centres. Singapore’s issue of low rate of population is similar to that of Japan. Cause: We are also facing a low birth rate because Singaporeans feel that families are a burden to their careers and lifestyles. The increased cost of living and raising children have added to this perceived burden.
Skills Builder: Suggested Answers Consequence: Similar to Japan, Singapore is also facing a shrinking talent pool and an increasing burden on the workforce to support the ageing population. Action taken: The government in Singapore has also embarked on campaigns to encourage family life and provides monetary incentives in the form of tax subsidies for couples who have more children.On the other hand, Singapore has been more open to immigration as opposed to Japan and has engaged in vigorous efforts to attract foreign talent to work and reside in Singapore.