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population - démographie
As population increases considerably, it is going to be an increasing burden on the planet. Demography takes thus an ecological dimension. This matter is the object of numerous debates on this subject.

In 1800, the planet had a little less than one billion inhabitants between 1800 and 1925, the population doubled, due notably to advances in medicine and sanitation over the course of this period (decrease of infant mortality and increase of life expectancy). The world population then increased from 4 billion in 1975 to 6 billion in 1999 then to 6.6 billion in 2008 [see debate].

Sustainable slowdown ?

Population growth reached its highest level in the 1990s with the increase of 82 million individuals per year. The numbers report an annual growth of 70 million in 2007 (Lester R. Brown, Plan B). The average number of children passed from 6 per woman in 1960 to about 3 today. It could reach two children per woman in the coming decades, just at the level of population renewal. According to the predictions of the United Nations, the world population will reach about 9 billion by the year 2050 then will stabilize.

Contrasting situations

Population situations can be very different from one geographic area to the next. Western countries have passed through their “population transition”, meaning that mortality has been considerably decreased because of medicine; on the other hand, the birth rate has also sometimes gone down below the renewal threshold. Their population ages and decreases sometimes even in a absolute number, even when counting new inhabitants resulting from immigration.

Conversely, a large part of the world has still seen strong population growth. In the coming decades, 96% of this growth will take place in developing countries. According to the FNUAP (Fonds des Nations unies pour la population), the population of the 49 least advanced countries is going to triple. [see debate]

Today, the average age in the world is 28 years old and it can go up to 38 years old in 2050 because of the increase in life expectancy.

The role of women

A drop in fertility is mainly controlled by women. On the other hand, their fertility drops significantly with urbanisation because of access to better education, birth control methods (family planning), a career, and an environment that, far from encouraging large families, discourages them.

However, in countries where little boys are preferred to girls, as in India or China, and where ultrasounds are available to determine the children’s sex before their birth, parents give preference to male babies and abort girls. There would today a deficit of several tens of millions of women in these countries. [see debate]

The obvious differences in standard of living leads to a significant number of people trying to immigrate to richer countries—in Western Europe and the United States, through difficult journeys. Some leave their lives, most are the prey of human being traffickers. A growing portion of migrations occur today between the different “souths.”

In the 1960s, numerous ecologist intellectuals thought that the growing population would lead humanity to disaster. The most famous of them all, Paul R. Ehrlich, an American entomologist, published a book in 1968 with big success: “The Population bomb”. It predicted namely that hundreds of millions of people were going to die of hunger very soon in the greatest famines in the history of man. These didn’t come, in particular because agricultural production increased considerably.

Ecological footprint and depletion of resources

Even if predicted famines don’t occur, the increase in population implies the increase in needs for food and everyday goods. The world population exerts a growing pressure on the environment and on resources. When man’s ecological footprint is measured, it is realized that it exceeds the size of our planet: our lifestyle on global level is no longer sustainable [see ecological footprint]. However, there are big differences between populations. An Australian or an Etasunian consumes much more than a person from Burkina Faso: the impact of the first ones is 10 times higher than the last one.

Faced with this crisis, most ecologists strongly advise to drastically decrease the average man’s ecological footprint—and mainly reducing that of Western countries. Others defend a Malthusian sometimes misanthropic point of view: they think that it is necessary to reduce the size of the world population and think that one shouldn’t have children (even if their ideas don’t always agree with their actions).

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