The human population

Population Explosion population explosion The study of populations is known as demography Study previous trends to create future predictions Study economy and social status

Human population is increasing due to 1. Increase in food production 2. Technology advancements 3. Industrial + scientific revolutions 4. Hygiene 5. Medication

Tools to help… Age Structure Categorization of population by age groups Age pyramid Plot of births within a pop High birth rate = more young than old Slow growth = equal distribution

Fertility Rate The number of babies born per year per 1000 women TOTAL FERTILITY RATE- Avg # of children given birth to per woman in her lifetime REPLACEMENT LEVEL- Avg # of children needed per couple to replace themselves ~ = first time in US history birth rate was below replacement level.

Survivorship Curve Type I- most individuals live to very old age then rapidly die Type II- Similar death at any age Type III- many offspring die to reach a certain age then slow die off Survivorship = % of members of a group likely to survive to a given age

Other factors leading to population changes Migration - movement of individuals between areas Immigration = movement into an area Leads to increase in population size Emigration = movement out of an area Leads to a decrease in population size

DECLINING DEATH RATE Led to increased life expectancy LIFE EXPECTANCY = avg # of years a person is predicted to live. Most impacted by infant mortality Based on parents access to education, food, fuel, and clean water 2009 US life expectancy = 78.2 years Japan has longest life expectancy at 82.6 World life expectancy = 67.2

Women + Fertility Women have the largest impact on the decrease in birthrate… in areas with low birthrates you will notice… Women are more independent Aware of better family planning practices Higher education Children become more of a financial burden because women are no longer home

As growth rate rises so do problems 1. Shortage of fuelwood 2. Unsafe drinking water 3. Negative land impacts

1. Shortage of Fuel wood Wood is the main fuel source in many poor countries. As populations rise more and more trees begin to be cut and are depleting resources.

2. Unsafe drinking water Water is breeding ground for disease-causing organisms. >1.2 billion people had no access to safe water and over > 3million deaths/yr Fuel wood is used to boil water to kill bacteria + make palatable. Water needed for drinking, bathing, washing, sewage.

3. Land Impacts Arable land needed for growing of crops to support a population. Should land be used for agriculture, housing, or natural habitat? Urbanization- more people moving towards cities which leads to suburban sprawl. Leads to increase traffic due to infrastructure overuse, overcrowding of schools, hospitals, etc. Decrease in land because of building More dense population

Demographic Transition Pattern of demographic change from high birth and death rate to low BR and DR.

Stages of the transition 1. Preindustrial 1. High BR + DR 2. Stable population 2. Transitional 1. Population explosion 2. Drop in DR due to hygiene, education 3. Industrial 1. Slow pop growth bc drop in BR 2. Stabilization when BR and DR become close 4. Post-industrial 1. BR below replacement level 2. Decrease in pop size

Not all countries follow the transition Least developed countries Very little sign of development High death and high birth rates Afghanistan, Bangledesh, Cambodia Developed countries Low birth rate and low death rate Developing countries High birth rate and low death rate.

1994 ICPD International conference on Population and development. 1. Reduce infant mortality to <35/1000 births 2. Reduce mortality of <5yr olds 3. Close gap in maternal mortality 4. Increase life expectancy to 75 in dvped and 70 in developing. 5. Create universal access to completion of primary education. 6. Create access to education to women