The study of human populations Demography The study of human populations

Demography: study of human populations with respect to their size, structure and development. Why do we need to know about changes in human population? To help plan for present and future needs of a population

Terms and Definitions Birth rate (BR): number of live births per year per 1000 people Death Rate (DR): number of deaths per year per 1000 people Infant Mortality Rate (IMR): number of deaths of children below one year of age per 1000 people Rate of Natural Increase (RNI): excess of births over deaths per 1000 persons also referred to growth rate

Terms and Definitions Population Density: number of people per sq. km of an area Total Fertility Rate (TFR): average number of children each woman would bear during her childbearing years Replacement Fertility Level: level of fertility at which a given population is replacing itself.This is usually calculated at 2.1 children per woman Zero Population Growth: When the BR is the same as the DR.

History of the Global Population Until about 200 years ago, population growth was slow. Since then, there has been an enormous increase which has been called the Population Explosion.

Human Population Growth Year Population 10,000 BCE 5-10 MILLION 1 CE 170 MILLION 1800 1 BILLION 1930 2 BILLION 1960 3 BILLION 1975 4 BILLION 1987 5 BILLION 1999 6 BILLION 2010 6.8 BILLION

It is important to note that it took all of human evolution (about 3 million years) for human population to reach 3 million in 1960 This just so happens to be the year Mrs. Walsh was born It has only taken 47 years for the world’s population to reach 7 billion. Most geographers believe that the world’s population will eventually even out at somewhere between 9- 11 billion in the next 25-50 years.

World Population Growth Doubling time time it takes population to double its size 10 million to 20 million 100 million to 200 million 6 billion to 12 billion This is calculated using the Rule of 70 70 divided by the % rate increase = doubling time 3% increase = 23 yr doubling time (70/3 = 23.3)

World Population Growth: Population Increase

Population Pyramids Population Pyramids give detailed information about a given pop. at a given time but can also be used to predict future trends. They show: Age Young at the bottom; elderly on top; Gender females on one side, males on the other

Building Population Pyramids

Building Population Pyramids

Building Population Pyramids If we were to display these graphs horizontally, make a mirror image of the one for women, and then join them together, we would have a population pyramid—exactly as seen on the next slide. The ages are divided into 5 year groups called cohorts.

http://www.statcan.ca/english/kits/animat/pyca.htm http://www12.statcan.ca/english/census01/products/analytic/companion/age/cda01pymd.cfm Better one!!!

http://www.census.gov/ipc/www/idbpyr.html

World Population Growth This shape indicates EXPANDING POPULATION because there are so many young people who will be old enough to have children in the next 20 years.

World Population Growth This pattern shows SLOW GROWTH, the sides are more or less even until the thirties.

World Population Growth This represents NEGATIVE GROWTH or pop. decline – notice the small numbers under age 15.

FUTURE World Population Growth New Developments Fertility is decreasing Decreases found even in countries that are not experiencing economic development Reasons for decreased fertility Family planning programs Modern contraceptive technology Mass media and the “information revolution” Urbanization

World Population Growth However there are still powerful factors against population control Cost Religion Low status of women Preference for male children Lack of education

Reasons the World Population may decrease Increases in death rates Wars and natural disasters Increase of known diseases: malaria, influenza New diseases- HIV/AIDS More smoking in developing countries Chemical pollution of humans

Demographics and Canada Between 1994 and 2004 Canada's population growth was close to 1% HOWEVER our Rate of Natural Increase was only 0.39% and the TFR was 1.5 per woman (far below the 2.1 required to maintain population) If we are to maintain or increase our population it will have to come from international immigration.

Even today immigration is the only reason why our population is increasing. This is a real concern giver the huge numbers of baby boomers who are going to retire in the nest 25 years. They will be relying on pensions paid by the government/ taxpayers for money