HUMAN POPULATION
Growth and Control

Demography



The study of populations, specifically human population
Demographers study the size and makeup and compare countries and make predictions of the future
Divided into 2 groups

Developed – higher income, slow growth, strong social support

Developing – lower incomes, agricultural based economy, fast growing

Human Population Over Time

Human population has grown exponentially over time beginning in the 1800s...why?

Forecasting Population Size: Age
Structure
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Age Structure – the spread of ages in a specific population at a certain time
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3 types of population pyramids

Rapid Growth

Countries with more young people

Example: Nigeria

Slow Growth

Countries with fewer young people

Example: USA

Zero or Negative Growth

Countries that have much fewer births

Example: Germany

Forecasting Population Size:
Survivorship

Survivorship –percentage of members of a group that are likely to survive to a given age
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3 types of survivorship curves

Type I

Death late in life

Type II

Death steady throughout life

Type III

Death early in life

Forecasting Population Size: Fertility
Rates

Fertility rate - the number of babies born each year per 1000 women

Total fertility rate – average number of children a woman gives birth to in her lifetime

Currently – 2.1

Forecasting Population Size: Migration

Migration – movement of individuals between areas

Immigration – into an area

Emigration – out of an area

Declining Death Rates

Why are deaths decreasing?

Improved medicine

Better access to education
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Better food

Cleaner water

Safe sewage disposal

Changing Population Trends

CHANGING POPULATION
TRENDS

Infrastructure

The basic facilities and services that support a community, such as

Water supplies

Sewage lines

Power plants
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Roads
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Subways
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Schools
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Hospitals

Problems of Rapid Growth

Use resources faster than the environment can renew them unless they come from somewhere else

What resources do you think are most critically affected by rapid growth?

Vegetation

Water

Land

A Shortage of Fuelwood

In areas where trees don’t drop dead branches to use as fuel, people begin to cut down trees reducing the number of trees left each year to use, ruining vegetation.

A supply of fuel allows people to do what?

Boil water to drink

Cook

Unsafe Water

Results in...

Bad drinking water
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Dirty water to wash with
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No sewage disposal

Many countries cant expand their water systems as fast as they are growing

Impacts on Land

Growing populations have a shortage of arable land, which is land that can be used to grow crops

Much of the world’s population is undergoing urbanization, building and living in urban areas instead of rural