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Even though there are signs of improvement in many peripheral, less-developed countries, unabated population growth continues. Do high fertility rates in one part of the world somehow counteract low fertility rates in others so that over-population no longer endangers the health of the planet?
Or will the fact that in the coming decades there might be half as many people in Europe, and twice as many people in Africa, create its own set of unique problems?
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11 Billion People
Live Science recently completed a weeklong series on the potential impact of a global population of 11 billion people. Why 11 billion? A recent report by the United Nations suggested that the Earth might be home to 11 billion people by the end of the century.
Most population projections don’t reach that far into the future with good reason. While populations change slowly, and trends in population are fairly easy to predict in shorter time frames, the further you try to predict into the future, the more assumptions you have to make and the less accurate your predictions are.
But whether it’s seven billion, 11 billion or 20 billion, one thing remains clear – it’s the distribution of people, and their economic situation, that will determine their impact on the planet, and how fiercely they will feel the pressure of resources stretched thin.
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Food, Water and Health Issues
When scholars discuss issues relating to over-population they typically focus on either threats to human welfare such as food and water security, poverty, health problems, and lack of sanitation, or they highlight environmental consequences such as loss of biodiversity and human impact on the climate.
According to Live Science, while experts agree that the planet can produce enough food for 11 billion people, food security in the future is “not a simple matter of producing more food.” Food security depends on a number of factors, including price, sustainable production, and appropriate use (food versus fuel).
In terms of water security, billions of people are already in trouble. Legal and/or physical conflicts over water occur regularly throughout both the developed and less-developed world. Even where water is less scarce, water quality is frequently an issue. Industrial and urban pollution, coupled with a widespread lack of sanitary facilities has led to human waste disposal problems and public health issues.
Human health is also at risk from infectious diseases, spread by too many people, crowded into ever-smaller spaces, and from our increasingly-globalized world where trade and travel quickly connect people and places around the globe. In terms of biodiversity loss, most ecologists agree that habitat loss is the number one driver of species extinction on earth. As human populations increase, habitat is either lost outright, or fragmented to the point where it can no longer support the plant and animal life it traditionally supported.
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But it’s not as simple as high population - bad, low population - good. In countries where a reduction in the fertility rate has led to a decline in the population – in Europe, Australia, and the United States – the structure of the population may change too quickly, or too severely, for existing infrastructure.
A rapidly aging population and a shortage of workers can lead to social and economic turmoil. And while fertility rates are slowly starting to fall in traditionally high rate areas, such as Africa, there is no guarantee that cultural, political or economic attitudes will continue to support the decline.
Other social challenges arise from changes in mortality rates. Mortality rates may increase, or decrease, based on the transmission of disease, development of successful treatment, and accessibility to health care. In politically unstable areas with high populations and no food security, mortality rates may prove a more powerful predictor of future population trends than fertility rates. What may turn out to be the most significant factor to consider in the over-population debate is whether a society is prepared to deal with whatever the future size, growth rates or composition of the population turn out to be.
As if to prove what some researchers have suggested – that any predictions past 2030 are little more than guesses – the United Nations estimates “the number of humans populating the planet in 2100 will range from as few as 6.2 billion (almost a billion less than today) to as many as 15.8 billion on the high end.”
Another guess? The International Institute for Applied Systems Analysis stated “if the world stabilizes at a fertility rate comparable to that of many European nations today (roughly 1.5), the global human population will be only half of what it is today by the year 2200, and only one-seventh by 2300.”
- "What 11 Billion People Mean For ...", LiveScience, http://www.livescience.com/41308-11-billion-people.html
- "Oh, the Humanity: Is the Threat of Overpopulation Still a Big Deal?", Scientific American, http://www.scientificamerican.com/article.cfm?id=human-overpopulation-still-an-issue-of-concern
- World Population to 2300, United Nations Department of Economic and Social Affairs/ Population Division, http://www.un.org/esa/population/publications/longrange2/longrange2.htm