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So Many of Us!
Population growth dramatically
affects the relationship of a species with its surroundings.
In this section we offer some basic demographic data.
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countries have higher birth rates/Mauricio Ramos. |
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1 - Has human population grown over time?
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Yes.
The number of people on the planet has increased throughout
human history. Over thousands of years human population
grew very slowly, reaching 1 billion in 1800. By 1930
it had doubled; by 1975 it had doubled again. In mid-1990,
world population was estimated to be 5.3 billion; it
is expected that by 2025 world population will reach
8.6 billion.
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2 - Why has world population grown so rapidly over the last
200 years?
Population has grown because mortality
declined faster than fertility. Improved sanitation, health
care, medicines, shelter, and nutrition have led to dramatic
increases in life expectancy. Fertility, on the other hand,
began to decline more recently than mortality, and it declined
more slowly. The result has been population growth.
3 - How
do we measure fertility and mortality?
These
variables can be measured in a number of different ways. The
simplest are the birth and death rates, which measure the average
number of live births and the average number of deaths for every
1000 people in a single year. In 1990, for example, there was
an average of 26 live births and 9 deaths for every 1000 people
on the planet.
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- Has population growth occurred evenly throughout the world?
No.
After growing rapidly in the nineteenth and early twentieth
centuries, the population of the industrialized countries of
the world has stabilized. In the less developed regions of the
world rapid population growth began later but has not yet ceased.
As a result, the developing countries are home to an increasing
percentage of the world's population. In 1950, North America,
Europe and the USSR contained almost 30% of the world's people.
By 2025, they will contain only 14%. India, in contrast, will
be the home of 17% of the world's population in 2025. The vast
majority of population growth today is occurring in the poorer,
less developed regions of the world.
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Source:
Primer on Environmental Citizenship.
Copyright © 2000 Tierramérica.
Todos los Derechos Reservados
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