1. World Population Social Studies 11

2. World Population The world population is the population of humans on the planet Earth In 2009, the United Nations estimated the population to reach 7,000,000,000 in 2011 - Current estimates by the United States Census Bureau put the population at

3. Demography Demography is the statistical study of human populations. Studying demography helps us to understand the causes and consequences of population change Help us to understand population pressure on the natural environment All levels of government need accurate population figures so to plan for future infrastructure Census is a way of gathering population information

6. Why is population distributed in this way? In what locations is population greater? What are the reasons for greater populations in certain areas and not in others?

7. Population Distribution Population distribution refers to the way people are spread over the Earth’s surface. Approx. 35% of the world’s land is not good for settlement Two-thirds of people live within 500km of the ocean

8. Population Density Population density is the number of people in a given area Rural and urban densities differ dramatically in most countries There are different explanations for the different population densities found in countries  Human and physical factors

9. Population Growth Components of Population Change: - How many people are born - How man people die - How many move in or out of an area Crude birth rate is calculated by dividing the number of births in one year by the population and then multiplying the result by 1000  Crude death rate is calculated with the same method  Natural increase = Crude death rates – Crude birth rates

10. Population Growth Continued Rule of Seventy  a way to express exponential population growth  Doubling time is approx. equal to seventy divided by the rate of growth per year  70 divided by 1.5 (per cent growth per year) = 46.7 years

11. Life Expectancy Life Expectancy is the average number of years that an individual is expected to live Disease, poor medical care, poor nutrition, and unsanitary living conditions contribute to one life expectancy The development of a country’s infrastructure can also influence one’s life expectancy  Ex. Hospitals, Water Treatment, Government, Education

12. The Demographic Transition Model Dramatic changes followed first the Agricultural Revolution some 8,000 years ago, and later the Industrial Revolution 250 years ago, when improvements in food supply and changes in health and hygiene triggered unprecedented population growth. In the 1930s and 1940s, demographers proposed a model to explain the demographic changes observed in Western Europe between the late 18th and early 20th centuries.

13. The Demographic Transition Model Continued The Demographic Transition Model shows changes over a period of time in three elements: birth rates, death rates, and trends in overall population The model assumes that in any country will shift from high birth rates and high death rates to low birth rates and high death rates The model is based on what has happened in developed countries Assumes that all country’s will pass through period of industrialization and urbanization

15. Population Pyramids Population Pyramids are graphs that show the age and sex structure of a population They are back to back bar graphs that compare male and female populations every 5 years ie. cohorts They are useful in comparing the population structure of different countries

16. I Can… Define dependency ratio Clearly explain how dependency can effect society

17. Read Titles & Headings, they are a good indicator of what you will be reading Read Topic Sentences, they are a good indicator of what you will read in the paragraph Read for important points and supporting evidence

18. Dependency Ratio Dependency Ratio is the proportion of the population that is being supported by the working population Children and Older people are considered dependents and are provided:  Medical, education, housing, and other services The age structure of the world’s population is changing There has never been so many people in the dependent category, where are the jobs going to be? At the same time, country populations are aging, who is going to look after them? Country’s are going to face different challenges