Worldwide Population Growth Population Geography World Geography and Cultures Chapter 4
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Population Geography World Geography and Cultures Chapter 4 Worldwide Population Growth At the dawn of the 1st century CE the world’s population was a measly 200 million The population of the US is just under 300 million Today, the global population is over 6 billion Factors leading to rapid population growth More food production Improved sanitation As population increased – so did (naturally) the number of women of childbearing ages z They - predictably – had children Total number of children meant the number of women who would be of childbearing ages also increased Population geographers study Birth and death rates Distribution of population Density of population 1 Millions vs. Billions Money: $1,000,000 z 11 cm (4.3 in) high stack of $1,000 bills. $1,000,000,000 z 109 meters (357 ft) of $1,000 bills Time 1 million seconds = 11.6 days 1 billion seconds = 31.7 years Speed The Concorde could circle the globe in 18.5 hours going 1340 mph z 31 days to go 1,000,000 miles z 85 years to go 1,000,000,000 miles Birth and Death Rates There are several ways to study the ways population grows and how healthy a population is Birth rates z Number of live births per 1000 population This number includes males & females Fertility rates z Average number of children a woman of childbearing years would have in her lifetime, if she had children at the current rate for her country Replacement rate is 2.1 Current world fertility rate is 3.0 2 Birth and Death Rates Geographers study population decline Mortality rate = death rate z z Number of deaths per 1000 people This number can be misleading when a healthy population begins to age Western Europe Infant mortality rate z Number of deaths among infants under 1 year per 1000 live births As technology, sanitation, and medical knowledge improve – the number of children who survive infancy also increases 1800s – worldwide rate was 200-300 Today the highest number is 110 Lowest numbers are: US (7.0), UK (5.7) and Sweden (3.5) Natural increase or population growth rate z The difference between the mortality rate and the birthrate Population Pyramids! (not that kind…) Graphic devices which show age & sex distribution of an entire population They help us examine how events in a society (war, famine, epidemics, baby booms) can affect the population of a country or region 3 World Population Cartogram This cartogram displays countries by the size of their population rather than their land area. (Only countries with 50 million or more people are named.) 4 Demographers assume that world population will stabilize at about 10.7 billion just after the year 2200 with over 95% of the growth occurring in countries now considered “developing.” Population Distribution 90% of the world’s population live in the Northern Hemisphere 2/3 of the population live between 20° and 60° N. Latitude 50% of the world’s population live in South Asia and East Asia Factors determining distribution Climate Altitude Access to water Most populations are concentrated along coastal regions and river valleys 5 Urban-rural distribution More than ½ the world’s population lives in rural areas z z Urban areas are built-up (cities) Rural areas are agriculturally based Urban migration People are moving to the cities from rural areas (especially into cities which already have 1 million +) Megalopolis Huge cities with more than 10 million Currently 26 in the world today z Largest are Mexico City and Tokyo (+ 28 million) 6 Population Migration Reasons for migration are referred to as push-pull factors Push factors z Those reasons which will drive an individual or group out of one area Environmental, political/religious Pull factors z Those reasons which will entice, draw, or pull an individual or group into an area Economic opportunities, political/religious freedom, climate Dorthea Lange “Migrant Mother” 1936 Population Density Density is measured by the average number of people who live in a measurable area Persons per sq. mile (or kilometer) This number can be misleading when looking at an entire nation 1990 the US’s population density was 70.3 z z Alaska = 1/sq mile New Jersey = 1,098/sq mile Carrying capacity The number of organisms a piece of land can support Factors influencing population density and carrying capacity Fertility of land (arable) Level of technology Economic activities 7
