Population
According to the non-profit group
Population Connection (formerly ZPG)
there are 6,641,215,403 people in the
world, up from a figure of 6,603,567,010
the last time I taught this course (Spring
2007). We’ve added over 37.6 million
people in that time.
Since World War II, the rate of growth has shot up.
Since 1965, world population has more than doubled.
Neo-Malthusians or “Population Bombers” (e.g., Paul
Ehrlich, Lester Brown, Garret Hardin, and David Pimentel)
have long argued that we are in danger of exceeding
Earth’s carrying capacity.
Over the past few years, we have experienced the
slowest growth since the 1940s. Cornucopians or
“Population Optimists” (e.g., Julian Simon) believe that
population is not that big a problem and that economic
growth and technology will see us through.
Still others claim that our focus on human population
growth is misplaced. They view excessive growth as a
symptom of other bigger problems. People in this camp
are “Gender Equity” or “Equity” Advocates.
More on these perspectives later . . .
As environmental geographers, we are
interested in knowing . . .
What significant population patterns are out there
Why these patterns exist and persist
Where significant population growth is occurring today
Where populations have stopped growing (or at least
slowed down)
What the environmental impacts of population growth
are
World's 10 Most Populous Countries: 2007
Rank Country Population
1. China 1,321,851,888
2. India 1,129,866,154
3. U.S. 301,139,947
4. Indonesia 234,693,997
5. Brazil 190,010,647
6. Pakistan 169,270,617
7. Bangladesh 150,448,339
8. Russia 141,377,752
9. Nigeria 135,031,164
10. Japan 127,467,972
World's 10 Most Populous Countries: 2000
Rank Country Rank
Population (2007) Country Population (2000)
1. China 1.
1,321,851,888 China 1.265 billion
2. India 2.
1,129,866,154 India 1,002 billion
3. U.S. 3.
301,139,947 U.S. 281 million
4. Indonesia 4.
234,693,997 Indonesia 212 million
5. Brazil 5.
190,010,647 Brazil 170 million
6. Pakistan 6.
169,270,617 Pakistan 151 million
7. Bangladesh 7.
150,448,339 Russia 145 million
8. Russia 8.
141,377,752 Bangladesh 128 million
9. Nigeria 9.
135,031,164 Japan 127 million
10. Japan 10.
127,467,972 Nigeria 123 million
If one were to analyze a series of world population density
maps published over the past several decades, two
important points emerge:
1) Population is not distributed uniformly around the world.
Some areas support large populations (One out of every three
people in the world is from either India or China); other areas
are very sparsely populated.
2) Population patterns and rates of growth change over time.
With respect to growth rates, there are tremendous disparities
around the world. We live in “two very different demographic
worlds,” one relatively small, old, and wealthy (with very high
consumption rates per capita) and the other very large, young,
and poor (with relatively low consumption rates per capita).
Speaking of Consumption . . .
If everyone in
the world
consumed like
the average
U.S. citizen,
we would need
four more
planet Earths
to meet
everyone’s
needs!
Population Distribution
MDCs account for 20% of world population but consume
the lion’s share of resources. Some countries (e.g.,
Denmark, Sweden) have reached ZPG (births plus
immigration = deaths plus emigration); others have
negative growth rates (e.g., Italy, Germany, Hungary,
Japan).
LDCs account for 80% of world population. Some
countries (esp. in the Middle East and Africa south of the
Sahara) have very high growth rates. Nigeria - the most
populous country in Africa - had 33 million inhabitants in
1950. By 2050, it is projected to have 300 million.
By 2025, MDCs will account for only 16% of world
population. This is because over 90% of population
growth over the next 30 years will occur in LDCs (esp.
“hot spots” Africa and Middle East)
Demographic Momentum
In at least 68 countries, more than 40% of the population is under
the age of 15.
Afghanistan (42.9%), Benin (47.9), Cambodia (45.4), Ethiopia
(46.0), Haiti (42.6), Pakistan (41.8), Syria (46.1), Libya (48.3)
Over the next class period or two, we’ll
examine these and other issues more
closely, as well as explore different ways of
looking at population growth & distribution:
different types of maps
population pyramids
different perspectives
A couple of things to remember about
maps and numbers . . .
1) maps are generalizations, interpretive
tools - we need to read them carefully
2) population by political boundaries can be
deceiving
3) population numbers can be deceiving
On October 12, 1999, the UN announced
that world population had officially reached 6
billion people.
How accurate were the data upon which this
statement was made?
Some countries do not have reliable census
data. Some countries may wish to overstate
or understate their populations. Why?
World Population Concentrations
East Asia
South Asia
Southeast Asia
Western Europe
N.E. U.S./S.E. Canada
Axiom for the day . . . People live
where they can eat!
People tend to live in arable areas
People tend to live in areas that are
accessible (especially by water)
People tend to migrate to areas where
others have migrated
Historically, what has caused world
population to grow?
When we look at world population growth
over the past several thousand years, we
see that it has not grown evenly. There
have been spurts in growth.
Spurts in population growth (Three
Revolutions)
ca. 8000 B.C. - Agricultural Revolution (plant
and animal domestication)
ca. 1750 A.D. - Industrial Revolution
(agricultural mechanization, transport,
sanitation, health)
ca. 1950 A.D. - Medical Revolution (elimination
of many historical causes of death)
And it keeps on growing . . .
It took all of human
history to reach 1 billion
people in 1804. Then it
only took 150 years to
reach 3 billion by 1960.
And as I noted earlier,
world population has
doubled since 1965.
How do we measure population
changes?
Rate of Natural Increase - Percentage by which a
population grows in a year (birth rate minus death rate).
Does not take migration into account. Current rate is
about 1.3%.
Doubling time - Number of years needed to double a
population. Current doubling time is about 53 years for
the world (Calculated by dividing 70 by the natural
increase rate).
Recent evidence suggests . . .
that population growth is slowing down
that doubling time is increasing
Geographers also look at . . .
crude birth rate - total
number of live births
in a year per 1000
crude death rate -
total number of
deaths in a year per
1000
Geographers also look at . . .
total fertility rate - number of children a woman
will have during child-bearing years (ages 15-49)
Fertility Rates (Cont’d)
Some demographers argue that births per male is a
more effective measure.
Average fertility rate for the world is 2.7; 2.1 in the U.S.
Fertility rates across the globe have been on the decline
over the past 50 years - except in Africa. In Mexico, the
average family in 1975 had 7 children. In 2000, the
average was down to 2.5.
China introduced a policy known as “later, longer, fewer”
in 1971 followed by a 1 child per family policy since 1979
which has reduced the fertility rate. The rate has
dropped from 6.2 in 1949 to 1.6 in 2006. Negative side
effects - female infanticide and bride abduction.
Family planning Iran has also lowered fertility rates.
Geographers also look at . . .
infant mortality rate - number of infant deaths (<1 year)
per 1000 live births
95 percent of the estimated 529,000 maternal deaths in 2000
occurred in Africa and Asia.
life expectancy - number of years a newborn infant can
be expected to live
Even in the U.S. there are pockets where infant mortality is high
and life expectancy is low for some members of society (e.g.,
Native American Indians).
Why is population increasing at
different rates in different countries?
To answer this, we’ll talk about demographic
transition (demographer Frank Notestein ca.
1945) and then take a look at population
pyramids.
Nearly all the population growth is occurring in
poorer countries - those countries least able to
support the growth.
Demographic Transition - Process of
change in a society’s population
process with four stages (based on
European and North American
experiences)
every country in the world can be grouped
into one of four stages:
What lowers the death rate?
food security
improvements in water supply and sanitation
improvements in medicine
Why does birth rate drop after death rate?
decision to have fewer children is a cultural
one
fewer children needed in an industrial society
fewer children needed in an urban society
higher education and personal freedom for
women tend to lower birth rates
A couple of questions:
Do people base their decision on whether or not to have
children in purely economic terms?
Children are valued in different ways (e.g., Where there is
little opportunity for upward mobility, children offer status)
Is the DTM an accurate predictor of trends in LDCs?
Some LDCs stuck in Stage 2 (Birth rates have remained
high after urbanization and industrialization)
There may be a cultural preference in some countries to
have larger families
Population Pyramids
An analytical tool, a bar graph, that allows us to
examine the distribution of a country’s
population by age and gender.
Tells us something about dependency (young
and old).
Tells us something about the future as well
(demographic momentum).
The shape of a pyramid is determined by the
crude birth rate.
Population Projections
for Nigeria (2000, 2025,
2050)
Population Projections
for Hungary (2000,
2025, 2050)
Population Projections
for U.S. (2000, 2025,
2050)
Population Projections
for Chile (2000, 2025,
2050)
“Because labor was scarce and land plentiful, a low
person/land ratio existed. Hence, each family had to
reproduce its own labor force, and population grew rapidly
during the seventeenth and eighteenth centuries.
Industrialization ultimately helped to bring about a
demographic transition to smaller families, as children
ceased to become an economic asset. In Sturbridge,
Massachusetts, for instance, women marrying between
1730 and 1759 bore an average of 8.8 children, whereas
those marrying between 1820 and 1839 bore an average of
5.3 children. Nationwide, women who married in 1800
bore an average of 6.4 children, but in 1849 the figure was
4.9 children and in 1879 it was 2.8 children.”
- Carolyn Merchant
Overpopulation?
What does overpopulation mean? Population exceeds
carrying capacity.
What does carrying capacity mean? The maximum
population that the environment can support indefinitely.
Is there an overpopulation problem in the world today?
In the U.S.? This is a debate that has been unfolding for
centuries.
Overpopulation?
Today the debate is carried on by . . .
Neo-Malthusians (a group named for English
economist Thomas Malthus)
Gender-Equity and Equity advocates (who trace
their roots to the writings of Karl Marx), and
Cornucopians (best represented by the work of the
late economist and statistician Julian Simon)
Overpopulation?
Thomas Malthus (1766 - 1834) was an English essayist and
minister whose 1798 treatise on population got the ball
rolling. It contained three key points:
food supply grows arithmetically while population grows
geometrically
passion between the sexes is constant and necessary
(Indeed, he had several illegitimate children!)
resources are limited
Overpopulation?
His conclusion? Collapse in the future.
His predictions have not come true – he
did not foresee technological advances,
especially where agricultural output is
concerned.
Must understand what was happening in
London at the time he was writing.
Overpopulation?
Neo-Malthusians (e.g., Paul Ehrlich, Garrett Hardin, Lester
Brown, David Pimentel) have revived some of his ideas.
Namely:
Population is an important issue because the planet is
already overpopulated.
Population growth puts unsustainable pressure on the
earth and its limited resources.
One of these days, we will overstep the Earth’s ability to
support us. We need to control population soon.
Overpopulation?
Karl Marx vehemently opposed Malthus’s positions,
arguing that population growth is a symptom rather than a
root cause of poverty, resource depletion, racism,
classism, and other problems.
Today, people like Betsy Hartmann and Paul Harrison have
picked up on this “equity” argument. They state that most
environmental problems have been caused by “first world”
countries and poverty in “third world” countries.
We need to raise standards of living, address the low
status of women, expand services, education, reproductive
rights.
They argue that the DTM works!
Overpopulation?
Then there are the Cornucopians. According to Julian
Simon, population may or may not be the cause of
environmental problems. He maintains that the quality
of life by a variety of measures is improving in many
places around the world.
To Simon, population growth is a good thing - people
are the “ultimate resource” and the more people on
earth, the more minds we will have working on our
problems.
The solution lies in economic policies that promote
economic growth.
He too argues that the DTM works!
In conclusion
Who is right? Each camp makes some good points.
Without a doubt, explosive and unchecked population
growth will have negative effects on the earth.
Without a doubt, resources and amenities are not
distributed equitably around the globe and poverty is at
the root of many of the world’s problems.
Family planning and education have done much to
reduce fertility rates around the world. We are better off
now in terms of reducing growth than we were 30 years
ago.
In conclusion
Can we concentrate our efforts on reducing fertility rates
in LDCs without addressing the consumption problems in
MDCs? No! Consumption rates in MDCs pose even
greater risks to the planet.
Although population growth is difficult to predict and
there are a variety of different viewpoints when it comes
to future projections, it is likely that world population will
level off around 8-10 billion sometime this century.
According to the U.N. Population Division, medium-range
population estimates for 2050 are down from 9.4 billion
to 8.9 billion. The U.N. estimates population might
stabilize at 9 billion by 2300.