By Jacob Mcilvaine
Recently I saw a video by Swedish doctor and statistician Hans Rosling about human population growth. It peaked my interest because I remember there being a lot of discussion in the news about the human population growing out of control when we reached 7 billion people back in 2012. Many pundits on television were talking about the day when the Earth would not be able to sustain our population and that we needed to start enforcing population control measures, extremists to say the least. I remember wondering if the population would ever stop growing. While our population is still growing it is not out of control, as those pundits thought. In fact, the rate at which the human species has been growing is slowing down.
The enormous growth of the human population in the 20th century is the most significant development in the past one million years. No other event, geological or biological, has posed a threat to earthly life comparable to that of human overpopulation. However, the human population growth rate peaked in the early 1970s at 2.2% and has been decreasing ever since. The growth rate is simply the difference between the birth rate and the death rate. Birth and death rates are calculated as the number of births or deaths per 1,000 people per year. The current growth rate of the entire world is about 1.14%. Although this seems like a small number, if the growth rate does not change, the human population will double in size roughly every 70 years. That means the human population would reach 14 billion people in 2084 and 28 billion people in 2154. However, according to Hans Rosling, the human population will reach its peak of 11 billion people by the end of this century. So why will the population stop growing?
Because the number of children in the world aged 0 to 15 has stopped growing. There are 2 billion children in the world right now. If you divide the world up by age spans of 15 years then you have five groups: 0 to 15, 16 to 30, 31 to 45, 46 to 60, and 61 and over. As of now, the first two groups each contain 2 billion people while the other three only contain 1 billion. The reason the older three age groups are missing 1 billion people is because they were never born. As time passes, the younger groups will age and replace the older groups, and 2 billion new children will replace the younger groups. This will continue until each group contains 2 billion people. That’s only 10 billion though, where will the last 1 billion come from? As healthcare advances people will start to live longer, adding an extra 1 billion people to the oldest group. This addition of 4 billion people is called “the big fill up.”
Another factor to consider is the distribution of the human population, and human population growth. They are not distributed evenly among the six inhabited continents, neither are they distributed evenly among the countries in those continents. As of now, the human population is distributed as follows: 1 billion people in the Americas, 1 billion people in Europe, 1 billion people in Africa, and 4 billion people in Asia. Just as the human population is not evenly distributed, neither is the growth rate. For example, many countries in Africa and Asia have growth rates over 2%, while countries in North America and Europe have growth rates under 1%. Some countries in Europe such as Germany and Russia even have negative growth rates, meaning that their populations are decreasing. Because the growth rates are much higher in African and Asian countries, “the big fill up” will happen entirely in those two continents. By the end of this century, 9 of the 11 billion people will be living in either Africa or Asia. Although the human population is still growing, it is not out of control.
Nadakavukaren, A. (2011). Our global environment: A health perspective. Prospect
Heights, IL: Waveland Press, Inc
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