Tuesday, November 1, 2011

A Whole Lot of People

A couple of days ago, the seven billionth human was born. The likelihood is that he or she is from Tamil Nadu, as this Indian state has one of the most explosive population growth in the world, but it’s equally likely that this new tiny earthling might be Chinese, French, or Texan.

We are a fertile breed. According to the Population Reference Bureau, “For the last 50 years, world population multiplied more rapidly than ever before, and more rapidly than it is projected to grow in the future. In 1950, the world had 2.5 billion people; and in 2005, the world had 6.5 billion people. By 2050, this number could rise to more than 9 billion 

“Anthropologists believe the human species dates back at least 3 million years. For most of our history, these distant ancestors lived a precarious existence as hunters and gatherers. This way of life kept their total numbers small, probably less than 10 million. However, as agriculture was introduced, communities evolved that could support more people.

“World population expanded to about 300 million by A.D. 1 and continued to grow at a moderate rate. But after the start of the Industrial Revolution in the 18th century, living standards rose and widespread famines and epidemics diminished in some regions. Population growth accelerated. The population climbed to about 760 million in 1750 and reached 1 billion around 1800.”

The PRB continues, “In 1800, the vast majority of the world's population (85 percent) resided in Asia and Europe, with 65 percent in Asia alone. By 1900, Europe's share of world population had risen to 25 percent, fueled by the population increase that accompanied the Industrial Revolution. Some of this growth spilled over to the Americas, increasing their share of the world total.

“…A billion people were added between 1960 and 1975; another billion were added between 1975 and 1987. Throughout the 20th century each additional billion has been achieved in a shorter period of time. Human population entered the 20th century with 1.6 billion people and left the century with 6.1 billion.”
In the late 18th century, Thomas Malthus studied the nature of population growth in Europe and claimed that population was increasing faster than food production. He feared eventual global starvation. Of course he could not foresee how modern technology would expand food production, but his observations about how populations increase were important. Population grows geometrically (1, 2, 4, 8 …), rather than arithmetically (1, 2, 3, 4 …), which is why the numbers can increase so quickly.

The PRB states that, “If a country's population begins with 1 million and grows at a steady 3 percent annually, it will add 30,000 persons the first year, almost 31,000 the second year, and 40,000 by the 10th year. At a 3 percent growth rate, its doubling time — or the number of years to double in size — is 23 years. The growth rate of 1.2 percent between 2000 and 2005, when applied to the world's 6.5 billion population in 2005, yields an annual increase of about 78 million people. Because of the large and increasing population size, the number of people added to the global population will remain high for several decades, even as growth rates continue to decline.”

We’re living longer, though not necessarily better, throughout the world.

And here’s something else that’s interesting. If we agree with the United Nation’s belief that 50,000 BC is the approximate beginning of the human race, when the world population was two, a possible total count of all humans who have ever lived will near 108 billion.  That’s a whole lot of people.

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