Population density is the measure of the number per unit area. It is commonly represented as people per square mile. which is derived simply by dividing... total area population / land area in square miles
World and Country Population Totals Distribution and Structure: 3/4 of people live on 5% of earth's surface! Total: 6.9 billion on planet as of September 27, 2011 Five most populous regions and countries REGIONPOPULATION COUNTRY POPULATION F East Asia1.6 billion China1.3 billion F South Asia1.5 billion India1.1 billion F Europe1 billion U.S. 300 million F SE Asia600 million Indonesia 250 million F Canada 275 million Brazil188 million
Human Population Growth How many people will the planet eventually support? The U.S. Census Bureau and the United Nations Statistics Division both agree that world population will level off somewhere between 9 and 11 billion people and then start to fall.
Doubling Time How long will it take for a population of a given area to double in size? Doubling time assumes the population will grow at a given annual rate Approximated by dividing the annual rate of population increase into 70 World = 50 U.S. = 35 MDC = 550 LDC = 40 Honduras = 22 Denmark = 700 Russia = never? Example: Bangladesh 70 / R.N.I. => 70/2.09 = 33.5 years Bangladesh with a population of 144.3 million people in 2005 will have approximately 288.6 million people in 2038, if the population continues to grow at current rates. Source: National Geographic Magazine
Infant Mortality Rate – the number of deaths of children under the age of one per thousand live births. The rate ranges from as low as 3 (Singapore, Iceland) to as much as 150 (Sierra Leone, Afghanistan). The U.S. rate is just over 6. High infant mortality tends to result in higher fertility rates as families seek “insurance” for the loss of children.
World Death Rates F Epidemiological Transition is the shift from infectious to degenerative diseases that occurs with development. F Infectious diseases (developing world) –HIV/AIDS –SARS –Malaria –Cholera F Degenerative diseases (developed countries) –Obesity –Tobacco use
Life Expectancy F Rapid increase throughout world F Infant mortality rate declining in most countries F Antibiotics/immunization F Increasing standards of living
Demographic Transition Model - was highly predictive for most countries
Demographic Transition Model F Stage one (preindustrial/pre-agricultural) –Crude birth/death rate high –Fragile, but stable, population F Stage two (improved agriculture and medicine) –Lower death rates –Infant mortality rate falls –Natural increase very high F Stage three (attitudes change) –Indicative of richer developed countries –Higher standards of living/education –Crude birth rate finally falls F Stage four –Crude birth/death rates low –Population stable –Populations aging
Population pyramids are used to show information about the age and gender of people in a specific country. MaleFemale Population in millions In this country there is a high Birth Rate There is also a high Death Rate. This population pyramid is typical of countries in poorer parts of the world (LEDCs.)
In some LEDCs the government is encouraging couples to have smaller families. This means the birth rate has fallen.
MaleFemale Population in millions In this country the number of people in each age group is about the same. The largest category of people were born about 40 years ago. In this country there is a low Birth Rate and a low Death Rate. This population pyramid is typical of countries in the richer parts of the world (MEDCs.)
Population in millions MaleFemale In this country the birth rate is decreasing. In the future the elderly people will make up the largest section of the population in this country. This is happening more and more in many of the world’s richer countries.
Male Female Population in thousands This country has a large number of temporary workers. These are people who migrate here especially to find a job.
Population pyramid for Mozambique. Population pyramid for Iceland.
Technology, Energy Consumption, and Environmental Impact There has been a dramatic increase in: individual energy use over time: 3,000 kcal/person - 300,000 kcal/person the power of technology to change the environment: think stone axe versus bulldozer versus atomic bomb. The scope and severity of environmental impacts.
Demographics characteristics of human populations and population segments
WHY DO WE MOVE? PUSH FACTORS (things that would push us to leave the area) Weather and Climate- Texas in August Cost of living – a house in Cali costs $450,000 Personal Safety – WAR, plague, famine Environmental Catastrophes – tsunami, earthquakes, hurricanes Emigration/Emigrant
PULL FACTORS (things that would pull us want to an area) availability of jobs religious or political freedom Safety Immigration/Immigrant