Human Populations Chapter 9

Demography… the study of populations births, deaths, income, economics, incidence of disease, social structure,… 7 Billion – NatGeo DF&index=2http:// DF&index=2 – 3 min

Demographers group countries as.... DEVELOPED  high average incomes  slow population growth  industrial economies  good social systems  good health care DEVELOPING  low average incomes  fast population growth  agricultural economies  poor social systems  poor health care

The Human Population….  grew slowly for 1000’s of years  1800’s – population reached 1 billion  1800’s to today - rapid (EXPONENTIAL) growth  today – population over 7 billion

For most of our human existence our ancestors led precarious lives as hunter- gatherers (some people still live like this)… this kept our population under 1 billion

The Industrial Revolution (1760’s) brought about better living conditions and advancements in medicine, education, sanitation,…..our population has grown to over 7 billion

Graph Source: & 10,000 BC - about 1 million of us 1800’s AD - about 1 billion of us 10,000 BC 1800’s AD

Graph Source: & TODAY, we are “off the chart” with a population of OVER 7 billion Exponential Growth – J curve In just 213 years (1800’s to 2013) our population has grown from 1 billion to over 7 billion)

TODAY…the U.S. Census Bureau estimates the World population at… World Population 7,071,548,673 18:35 UTC (EST+5) Mar 11, 2013

What’s your number? World Population Counter hyperlink

World population reached…  1 billion in 1800’s  2 billion in 1927 (123 years later)  3 billion in 1960 (33 years)  4 billion in 1974 (13 years)  5 billion in 1987 (12 years)  6 billion in 1999 (12 years)  7 billion in 2011 (12 years)  8 billion in ?  9 billion in ? Do you see a pattern? TAKEN FROM…

What About The Future… The projected estimates for 2050 are….  10.7 billion (high)  8.9 billion (middle)  7.3 billion (low) the world is adding about 78 MILLION more people every year

Remember Carrying Capacity? What is the Earth’s carrying capacity?  estimates billion Why do these estimates vary?  difficult to determine  scientists use different methods to get estimates

Our impact is increasing. LANDSAT Images 1973, 2000, 2006 Las Vegas, Nevada

Human Impact on The Environment year 1700, 2002, (projected) 2032 Source: Hugo Ahlenius UNEP/GRID-Arendal. Global Environmental Outlook 3, Human Impact on the Environment, 1700Human Impact on the Environment, 2002Human Impact on the Environment, 2032

Forecasting/Projecting Population Size Demographers make predictions about populations using…  Age Structure  Survivorship  Fertility Rates  Migration

Age Structure  distribution of ages in a population at a certain time  can be graphed using a population pyramid (seen below) Sweden and US have slow growth while Mexico has rapid growth

Survivorship  percentage of individuals likely to survive to a given age Centre County, Pennsylvania What was survivorship in 1819? 1859? 1879?

Survivorship Curve Type I – most individuals live to an old age – developed nations Type II – similar death rates at all ages Type III – most individuals die at early age – many developing nations

Fertility Rate… Fertility Rate = # of babies born each year per 1,000 women Total Fertility Rate = average number of children a woman gives birth to during her lifetime Total Fertility Rate varies from…  1+ - Japan and Italy - developed nations  7 - Niger and Mali - developing nations  United States – developed nation

Total Fertility Rate Developed countries – average 1.6 children per woman Developing countries – average 3.1 children per woman Why is this number higher in developing countries? REPLACEMENT RATE - the rate at which a population neither grows nor shrinks 2.1 is generally regarded as the replacement rate in the developed world

Palestinian TerritoriesFertility Rate Africa Fertility Rate U.K. Total fertility rate Do you notice any trends? TOTAL – 2 min min

Total Fertility Rate = # of babies per woman

Migration MIGRATION = movement of individuals between areas o Immigration - movement into an area (or population) o Emigration – movement out of an area (or population) Map shows first migratory routes taken by humans, based on surveys of different types of the male Y chromosome. "Adam" represents the common ancestor from which all Y chromosomes descended. Research based on DNA testing of 10,000 people from indigenous populations around the world. Source: The Genographic Project

Other Factors Affecting Population Growth Declining Death Rates Life Expectancy Infant Mortality

Declining Death Rates…. have allowed human population to increase more people have access to…. adequate food clean water sewage disposal vaccines/immunizations and antibiotics

Life Expectancy… - is increasing throughout the world - average # of years individuals of a population are likely to live Because of…  antibiotics  immunization/vaccines  improved standards of living  adequate food  clean water  better sanitation Life Expectancy Worldwide 67+ years Developed Countries 80+ years

Life Expectancy

Life Expectancy is most affected by… Infant Mortality (rate) = death rate of infants less than a year old (per 1000 live births) Infant Mortality varies … as low as 3 - Singapore + Iceland as much as Sierra Leone + Afghanistan just over 6 – United States High infant mortality tends to result in higher fertility rates as families seek “insurance” for the loss of children.

Infant Mortality Infant Mortality (death) is DECLINING in most countries Infant Mortality is MOST AFFECTED by the parents access to…. education, adequate food, fuel, clean water Expensive medical care is not as important

Infant Mortality

Demographic Transition F model that describes how economic and social changes affect population growth

Women and Fertility… Decline in birth rates due to …  Increased education  Economic independence for women

Influences on Birth Rates Family planning programs Contraceptive technology Role of mass media Government Billboard, Indonesia

Rapid Population Growth BRINGS ENVIRONMENTAL PROBLEMS 2. USES RESOURCES AT AN INCREASED RATE 3. CAN OVERWHELM INFRASTRUCTURE

Environmental Problems I = P x A x T Impact = Population x Affluence x Technology Population-influenced environmental problems…. Global Warming Habitat Loss / Endangered Species Resource Depletion Food Shortages? Not globally, but regionally..

Use of Resources at an Increased Rate (Resource Consumption) vegetation, water, land - most affected resources In chapter 1 we talked about the 2 root causes of environmental problems. What are they?

Shortage of Fuel Wood Fuel Wood = firewood, charcoal, chips, sheets, pellets, sawdust  often it is the most available form of fuel – for cooking + heating

Unsafe Water Local water supply may be used for drinking, washing and sewage disposal

Barren Land loss of Arable Land ( land used to grow crops)

Much of the World’s Population is undergoing URBANIZATION  URBANIZATION = movement of people from rural areas to cities  URBAN = cities and towns  SUBURBAN = residential area outside an urban area  RURAL = outside cities and towns = “country” What are some problems associated with urbanization?

Infrastructure INFRASTRUCTURE = basic facilities and services that support a community  public water, sewer, power plants, roads, schools, hospitals,… Overcrowded Schools Inadequate Housing

What might limit the human population? F Lack of resources – food, water, shelter F Emerging Diseases – Ebola, Hanta Virus, Lassa Fever, SARS,….

Population Growth is Slowing Challenges to Population Control –manufacture/distribution expense –religion –low female status u fastest way to reduce fertility rate is to educate women –preference for male children –female Infanticide

Human Population Forecasts/Projections How many people will the planet eventually support? it is thought that … world population will level off somewhere between 9 and 11 billion people

Overpopulation When consumption of natural resources by people outstrips the ability of a natural region to replace those natural resources.