Transcript Chapter 2
Chapter 2
Population
Key Issue 2
Key Issue 2
Where has the World’s
Population Increased?
Population increases QUICKLY in places
where….
More
people are born than die
Population
where….
increases SLOWLY in places
Number of births exceed number of deaths
by small margin
Population decreases in places where…
deaths outnumber births
Natural Increase
Geographers
use 3 measures to examine
population change
CBR:
total number of live births in a year
for every 1000 alive in society
CDR:
total number of deaths in a year for
every 1000 alive in society
Natural Increase
NIR:
Percentage by which population
grows in a year.
Convert CBR & CDR into percentages
CBR
of 20 = 2%, CDR of 5 is 0.5%
Subract CDR from CBR
2% - 0.5% = ______%
1.5%
NIR
Natural Increase
2000-2010:
World NIR was 1.2
Current population is over 7billion
What will the population be in 2 years?
Natural Increase
Small
percentage makes HUGE difference
2006 population:
6.6 billion x 1.2 NIR = 80 million people
(about 1/4 of US pop)
NIR affects doubling time = amount of time
it takes to double a population
At current NIR rate of 1.2, global
population will reach 24 billion by 2100
Natural Increase
Almost
100% of increased population is in
LDCs: Africa, Asia, Latin America, Mid East
Exceeds 2% in most LDCs
0% growth in Europe (negative #)
Natural Population is declining (does NOT
include migration)
NIR in LDCs
Natural Increase
Most
of world’s additional people live in
countries that CANNOT support them
Fertility
Highest
CBRs are in sub-Saharan Africa
(40), lowest in Europe (10)
TFR: total fertility rate measures average
number of children a woman will have in
her childbearing age (15-49)
Predicts
TFR
future behavior
in Sub-Saharan Africa = 6+
TFR in Europe = >2
Total Fertility Rate
Mortality
In
addition to CDR, IMR and life
expectancy are used to measure
mortality
IMR: annual number of deaths of infants
under 1yrs old, compared to live births
Highest IMR in sub-Saharan Africa, lowest
in W.Europe
Infant Mortality Rate
IMR
exceeds 100 in Africa
10%
of babies die before 1st bday
Reflects
a country’s health-care system
Low
IMRs have well-trained Drs, modern
hospitals, medicine
Why
does US have higher IMR than
Canada & Europe????
Minorities & poverty often cannot afford
good healthcare
Life Expectancy
Measures
average number of years a
newborn infant can expect to live
More favorable in wealthy countries (W
Europe), lower in poor countries (Africa)
Western Europe = 70s
Sub-Saharan Africa = 40s
MDCs vs LDCs
Natural
Increase Rate
Crude Birth Rate
Total Fertility
Infant Mortality
Life Expectancy
ALL follow similar trends!!!!
MDCs vs LDS
Crude Death Rate
Does
not follow familiar pattern
Which has higher CDR?
US or Mexico?
Denmark or Mongolia?
Populations
are at different states in the
Demographic Transition (Key Issue 3)
Key Issue 2 Summary
Virtually
all the world’s natural increase is
concentrated in the relatively poor
countries of Africa, Asia and Latin
America. In contrast, most European and
North American countries now have low
population growth rates and some are
experiencing population declines. The
difference in natural increase between
MDCs and LDCs is attributable to
differences in CBRs rather than in CDRs
What is crude birth rate?
Total
number of live births in a year for
every 1,000 people
With a partner…
Analyze
each map in Key Issue 2
Each of you comes up with a question
comparing the data.
Ask each other your questions to be
answered
What is crude death rate?
Total
number of deaths in a year for every
1,000 people alive in the society
What is NIR?
The
percentage by which a population
grows in a year
(subtract CDR from CBR)
What is the NIR today?
1.2
for the first decade of the 21st century
When did global NIR peak?
1963
with a peak of 2.2%
About how many people are
being added to the world’s
population each year?
About
80 million people
Define doubling time
Number
of years needed to double a
population
(assuming a constant rate of natural
increase)
In what world regions is most
growth occurring?
Clustered
in LDCs
Africa, Asia, Latin America & the Middle
East
NIR exceeds 2%
Negative NIR in Europe
Define total fertility rate
The
average number of children a
woman will have throughout her
childbearing years (roughly ages 15 to 49)
Define infant mortality rate
The
annual number of deaths of infants
under 1 year of age compared with total
live births
Define life expectancy
Measures
the average number of years a
newborn infant can expect to live at
current mortality levels