Prsentation PowerPoint

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Demography
The increase of the world population
Population histograms ranking/country
Population curves between Europe and Africa
Resources http//www.ined.fr/en/everything_about
_population/animations/world_population/
http//www.ined.fr/en/everything_about_population/
population_atlas/
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The increase of the world population
Introduction
In 1999, there were 6 billion people living on
Earth, and by 2011 or 2012, the population will
reach 7 billion. Why is the world population
increasing so fast ? And what will happen in the
future ?
Population growth today
World population history
The demographic transition
The future world population  explosion,
implosion, or equilibrium ?
Conclusion
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The increase of the world population
Population growth today
Every second, on average, four babies are born.
Every second, on average, two people
die. Every second, on average, the population
increased by two people. Two more people per
second means 200 000 more people per day, and 75
million more people per year. In other words, the
world population 6,5 billion in 2005 is
growing by 1,2 percent each year. At this 1,2
annual growth rate, the population doubles evrey
60 years. If the number of people on Earth
carried on increasing at this speed, the 6,5
billion in 2005 would become 13 billion in 2065,
26 billion in 2125 ans so on. But the population
does not grow at the same speed indefinitely. On
the contrary, the United Nations predict that the
world population will level off at around 9
billion people before the end of the century.
Why is that ?
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The increase of the world population
World population history
World population increase in the last two
thousand years
Billions of inhabitants
0 500 1000
1500
2000 years
Throughout most of human history, the number of
people on Earth could be counted in just hundreds
of thousands or in millions, and the population
increased very slowly. Two thousand yeras ago,
there were around 250 million people in the
world, and by the end of the 18th century the
total had reached one billion. At around that
time, the population started growing much faster.
From one billion in 1800, it rose to two billion
in 1927, 3 billion in 1960, 4 billion in 1974, 5
billion in 1987 and 6 billion in 1999. Whe
should reach 7 billion by around 2011 or 2012,
and growth will not stop there. So what will
happen next ? The United Nations are forecasting
that the world population will level off at a
mere  9 billion by around 2050. How did they
reach this figure ? And looking back in history,
why did the population grow so slowly up to the
eighteenth century ? Why did it start rising so
fast from then on ?
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The increase of the world population
The demographic transition
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The increase of the world population
The future world population  explosion,
implosion, or equilibrium ?
World population projections to 2300 scenario 1
Billions of inhabitants
1950 2000 2050
2100 2150
2200 2250 2300
years
In the demographic transition model, fertility
stabilizes at the remplacement level two
children per woman when mortality is low. The
United Nations have imagined a scenario in which
future families each have exactly two children on
average, in which case the world population would
level off after reaching 9 billion.
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The increase of the world population
The future world population  explosion,
implosion, or equilibrium ?
World population projections to 2300 scenario 2
Billions of inhabitants
1950 2000 2050
2100 2150
2200 2250 2300
years
But in many countries where the demographic
transition is complete, average fertility is well
below 2 children per woman. For example, it was
1,5 in the countries of the European Union in
2005, and 1,3 in Japan. If very small families
became a world-wide model over the long term, the
world population would peak at 9 billion then
start declining until human beings eventually
died out altogether.
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The increase of the world population
The future world population  explosion,
implosion, or equilibrium ?
World population projections to 2300 scenario 3
Billions of inhabitants
1950 2000 2050
2100 2150
2200 2250 2300
years
Fertility may also start increasing again in the
countries where it is currently very low,
stabilizing at 2,3 children worlwide. This would
result in continuous growth up to 37 billion in
2300 and here agaiun the ultimate disappearnce
of the human race, this time due to
overpopulation.
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The increase of the world population
The future world population  explosion,
implosion, or equilibrium ?
World population projections to 2300 scenario 4
Billions of inhabitants
1950 2000 2050
2100 2150
2200 2250 2300
years
Under the so-called  contant fertility 
scenario, in which fertility remains at its
current level for the next three centuries, the
population would reach 134 000 billion in the
year 2300 ! But this scenario is unrealistic,
since fertility is decreasing throughout the
world. It simply shows us how continuous growth
leads to explosion within a very short time.
These catastrophic scenarios, resulting in the
extinction of the human race through implosion or
explosion, are not the only alternatives. We need
to imagine a return to equilibrium over the long
term. The medium scenarios based on assumption
that achieve a long-term balance, such as
fertility of exactly two children per woman for
example. It is no more realistic than the high
or low scenarios, but simply shows what path
needs to be followed if we to survive beyond the
next few centuries.
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The increase of the world population
Conclusion
In 1999, Humankind is starting to control its
population growth. But to ensure a decent
standard of living for 9 billion people, we will
need to manage the planets resources more
efficiently and share them more equitably. Over
the long term, the survival of the human race
depends as much if not more upon our way of
life as upon our number.
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Population histograms ranking/country
1950
2000
2050
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Population histograms ranking/country
billions
billions
2
2
Population
1
1
1950 1975 2000
2025 2050
1950 1975 2000
2025 2050
8
8
Number of children per woman
4
4
1950 1975 2000
2025 2050
1950 1975 2000
2025 2050
millions
millions
220
220
Population aged 65 and above
110
110
1950 1975 2000
2025 2050
1950 1975 2000
2025 2050
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