Q: Birth rates are dropping all over the world. Isn't
the "population bomb" really a dud?
Birth rates have dropped to nearly half of what they were in 1950: from an
average of 5 offspring to 2.6. Our growth rate has also fallen significantly,
as this chart from the US Census Bureau
shows.
Annual population increase likewise has improved from a high of 87 million
in 1989 to around 74 million in 2005.
However, before we pop a cork to celebrate the fizzle of our population
explosion, there's one more chart -- one most often ignored.
Q: With birth rates, fertility rates, and growth rates all falling, how can our population keep on steadily rising?
Momentum.
Although couples are creating fewer of us, there are more couples creating
those new people, which makes more of us. For example, China's 1.5 TFR is way
below "replacement level fertility," and yet their natural increase is 10
million per year.
This serves as an ominous warning. If cutting fertility rates in half hasn't
stopped our increase, what will it take? How much better can we expect birth
rates to get? Many regions have reached a plateau and aren't likely to go any
lower unless conditions change.
Q: If we only produce two children, doesn't that just replace ourselves?
"Stop at two" may have been a radical proclamation when Zero Population Growth* was founded in 1968, but it was barely adequate even then. So-called replacement level fertility of 2.1 offspring per couple wouldn't bring about true zero population growth until the middle of this century, due to momentum.
Today the message is only slightly revised: "Consider having none or one, and be sure to stop after two."
The notion that producing two descendants simply replaces a couple and creates no increased impact is specious. We aren't salmon - we don't spawn and die. Most of us will be around to see our progeny beget, and those begotten beget to boot.
When a couple of us "replaces" ourselves, our environmental impact doubles - assuming our offsprings' lifestyles are as environmentally friendly as ours, and that they won't reproduce themselves.
The "stop at two" message actually encourages reproduction by "qualified" couples. Although a wanted child is better than unwanted, intelligent (whatever that is) better than stupid, and well-cared-for better than neglected, each of us in the over-industrialized world has a huge impact on Nature, regardless of these factors.
For example, in terms of energy consumption, when a North American couple stops at two it's about the same as an average East Indian couple stopping at 30, or a Bangaledesh couple stopping at 97. Per capita energy consumption by country.
Two is better than four, and one is twice as good as two, but to purposely set out to create even one more of us today is the moral equivalent of selling berths on a sinking ship.
Regardless of how many progeny we have or haven't produced, rather than stop at two, we must stop at once.
*Zero Population Growth - Population Connection
Population projection with a Total Fertility Rate of 1.0 starting nowGlossary of demographic terms from The Population Reference Bureau.
