Human Population DynamicsChapter 8

AP College BoardObjectives (10 – 15%)

1. Human Population dynamics – historical population sizes; distribution; fertility rates; growth rates and doubling times; demographic transition; age-structure diagrams

2. Population size – Strategies for sustainability; cases studies; national policies

3. Impacts of population growth – hunger; disease; economic effects; resource use; habitat destruction

Population Basics

Population: all the individuals of a species that live together in an area

Density: measurement of population per unit area or unit volume

Formula: Dp= N

Population Density = # of individuals ÷ unit of space

Factors that Affect Density

Density-independent factors- Abiotic factors in the environment that affect populations regardless of their density

  Ex. temperature

storms

habitat destruction

drought

Factors that Affect Density

Density-dependent factors- Biotic factors in the environment that have an increasing effect as population size increases

  Ex. disease

competition

parasites

Population Density and Distribution

How is Population Data Gathered?

Natural Increase Immigration and Emigration

Births minus Deaths

1,345 – 645= 700 Age structure Diagrams

o

Demography: A social science that applies the principles of population ecology to the study of statistical change in human populations

Population Pop Quiz

https://www.populationeducation.org/sites/default/files/pop_quiz_0.pdf

Population Basics Define the following vocabulary

a. Total fertility rate b. Replacement level fertility c. Infant mortality rate

d. Doubling time e. Mortality f. Natality

g. Life expectancyh. Immigration i. emigration

Immigration

Emigration

Natality MortalityPopulation+

+

-

-

Factors That Affect Future Population Growth

Human Population Growthhttp://www.populationconnection.org/site/PageServer

?pagename=issues_main

Human Population Growth

Our World at 7 BillionTo travel 7 billion miles in your car you’d need to

make 29, 000 trips to the Moon!Global population grows by over 80 million

people each year.We add 2.6 people to the planet every secondPopulation growth momentum: The continued

growth of a population after fertility rates have declined, as a result of a population's young age structure

http://www.npr.org/2011/10/31/141816460/visualizing-how-a-population-grows-to-7-billion?_sm_au_=iVVRHJkHQnPNnp16

 

How Did We Get to 7 Billion So Fast???

Almost 1 in 5 people in the world are Chinese…More than 1 of every 6 lives in India.

Predicting world Population Growth

Is Population Growth a Problem?

Human Population Growth

Thomas Malthus

British economist (1766-1834)

Argued that unless population growth were controlled by laws or other social strictures the number of people would eventually out grow the available food supply.

An Essay on the Principle of Population (1798)

“If society did not limit births then rising death rates would reduce the population through war, disease, and starvation.”

Human Population Growth

Paul Ehrlich

Biologist at Stanford University “neo-Malthusians”

The Population Bomb (1968)

Predicted that population growth would unleash famine and conflict that would consume civilization by the end of the 20th century

I = P x A x T

IPAT Model Paul Ehrlich and John Holdren* (1974)

*Holdren is a Harvard University environmental scientist. He is also President Obama’s science advisor;

Increased Population = more individuals take up space, use resources and generate waste.Increased Affluence = greater per capita resource consumptions that accompanies enhance wealth.Technology= exploitation of minerals, fossil fuels, old-growth forest and fisheries BUT ….Technology= reduces smokestack emissions, harnesses renewable energy, improves manufacturing efficiency

Mapping Our Population’s Environmental Impact

NPP = the net amount of energy stored in plant matter as a result of photosynthesis.Overuse of NPP diminishes resources for other species; alters habitats, communities, and ecosystems; and threatens our future ability to derive ecosystem services.

Read The Science behind the Story on pages 202-203. 1.How did scientist conduct the study?2.What data did the scientist collect?3.What were the results of their study?4.What can scientist conclude from the study?

What is Cultural Carrying Capacity?

Are you willing to have less space in which to live?

Less food to eat --- Less material wealth?

Growth RateWhat is the formula

for finding natural increase (growth rate)?r = b – d

r = 26/1000 - 5/1000r = 0.026 – 0.005 = 0.021

0.021 X 100 = 2.1% per year

OR (the easy way)

r = 26/10 - 5/10 r = 2.6 - .5 = 2.1 or 2.1% per year

Doubling TimeRule of 70 – determines the number of years

it will take a country’s population to double.

Doubling time = 70/%growth rate Growth rate = 70/doubling time

Let’s practice: A country’s growth rate is 1.5%. How many

years will it take that country’s population to double?

70/1.5 = 46.7 years

Calculate the annual growth rate and the doubling time for the following countries:

Country CBR CDR % increaseDoubling time (yrs)

Australia 15 7 Bangladesh 37 13 United States 13 8 Botswana 36 9 Canada 14 7 Germany 10 11 Haiti 42 19 India 29 10 Russia 11 12

Calculate the annual growth rate and the doubling time for the following countries:

Country CBR CDR % increaseDoubling time (yrs)

Australia 15 7 2.14 32.7 Bangladesh 37 13 2.5 24.6 United States 13 8 1.6 44 Botswana 36 9 4 17.5 Canada 14 7 2 35 Germany 10 11 .9 78 Haiti 42 19 2.2 31.8 India 29 10 2.9 24 Russia 11 12 .92 76

Demographic Facts of LifeGrim Reaper’s Revenge

As devastating as wars, natural disasters, accidents, diseases, etc. are, they often have little impact on overall population growth worldwide.

We are currently adding 228,000 people to the planet

each day = to 1 Hong Kong a month!. At

today’s present rate of growth, let’s

determine how many days it would take

to replace those lost.

How do population pyramids help us learn

about population?

PRE-REPRODUCTIVE

REPRODUCTIVE

POST-REPRODUCTIVE

Population pyramids are used to show information about the age and gender of people in a specific country.

Male Female

Population in millions

In this country

there is a high Birth

Rate

There is also a high

Death Rate.

This population pyramid is typical of countries in poorer parts of the

world (LEDCs.)

In some LEDCs the government is

encouraging couples to have smaller

families. This means the birth rate has

fallen.

Male Female

Population in millions

In this country the number of people in each age group is

about the same.

The largest category of

people were born about 40

years ago.

In this country there is a low Birth Rate and a low Death Rate.

This population pyramid is typical of countries in the richer parts of the

world (MEDCs.)

Population in millions

Male Female

In this country the birth rate is decreasing.

In the future the elderly people will

make up the largest section of the

population in this country.

This is happening more and more in

many of the world’s richer

countries.

Male Female

Population in thousands

This country has a large number of temporary

workers. These are people who migrate here

especially to find a job.

Population pyramid for Mozambique.

Population pyramid for Iceland.

What happens next?

What is going to happen to Japan’s population in the future?

Why does this matter?

?

?

?

You decide!

What is the Demographic Transition?

The shift from highhigh to low mortality and fertility

A sign of socio-economic progress?

Demographic Transition

Read pages 210-211What is the definition of demographic

transition?Identify the characteristics of each stage.

Stage DescriptionFirst Stage – Pre IndustrialSecond Stage -- TransitionalThird Stage -- IndustrialFourth Stage – Post Industrial