Chapter Nine: The Human Population

Section One: Studying Human Populations Demography: the study of populations The Human Population Over Time Underwent exponential growth in the 1800’s Unlikely the world can sustain this growth in the future

Section One: Studying Human Populations Forecasting Population Size Age structure: the distribution of ages in a specific population at a certain time Graphed in population pyramid More young people= more population growth Survivorship: the percentage of members of a group that are likely to survive to any given age Graphed in a survivorship curve Type of curve based on whether the country is developed

Section One: Studying Human Populations

Section One: Studying Human Populations

Section One: Studying Human Populations Forecasting Population Size Fertility Rates: the number of babies born each year per 1000 women in a population Total fertility rate: the average number of children a woman gives birth to in her lifetime Replacement level: the average number of children each parent must have to “replace” themselves in the population Migration: the movement of individuals between areas Immigration: movement into an area Emigration: movement out of an area

Section One: Studying Human Populations

Section One: Studying Human Populations Declining Death Rates More people have access to food, clean water, and safe sewage disposal Life expectancy: the average number of years the members of a population are likely to live Affected by infant mortality rate Infant mortality rate: the death rate of infants less than one year old

Section One: Studying Human Populations

Section One: Studying Human Populations The Demographic Transition The model that describes how economic and social changes affect population growth rates 4 stages of transition

Section One: Studying Human Populations

Section One: Studying Human Populations Women and Fertility Increasing education and economic independence has led to a decline in birth rate Total fertility rate in developing countries= 3.1 children Total fertility rate in developed countries= 1.6 children

Section Two: Changing Population Trends Problems of Rapid Growth Infrastructure: the basic facilities and services that support a community Ex: water supplies, sewer lines, roads, schools, hospitals Rapidly growing populations use resources faster

Section Two: Changing Population Trends Problems of Rapid Growth Shortage of Fuelwood Rapid growth lead to more wood being used and trees being cut down Wood is a main source of fuel in many countries Used for cooking food, boiling water, and keeping warm Unsafe Water Water may be used for drinking and sewage disposal Unclean water serves as a breeding ground for diseases Ex: typhoid, cholera, dysentery

Section Two: Changing Population Trends Problems of Rapid Growth Impacts on Land Arable land: land that can be used to grow crops Growing populations make trade-offs between competing uses for land such as agriculture and housing Urbanization: the movement of people from rural areas to cities

Section Two: Changing Population Trends A Demographically Diverse World Demographers use the terms more developed and less developed Least developed countries: show few signs of development and in some cases have increasing death rates, while birth rates remain high. May be given priority for foreign aid

Section Two: Changing Population Trends Managing Development and Population Growth Many countries such as China and India have tried to reduce birth rates through public advertising, family planning, economic incentives, or legal punishments

Section Two: Changing Population Trends Growth is Slowing Current human population= 7.3 billion Fertility rates are declining Projections for 2050 World population of about 9 billion by 2050