The United Nations’ population experts recently rocked the world by projecting the planet will be home to a larger-than-expected 10.1 billion people by 2100.
To some, the august body used statistical “magic” to arrive at this number. To others, the 10.1 billion figure is too low - a calamitous 15 billion people, they argue, is closer to the truth.
Welcome to the delicately calibrated and yet fractious world of long-term demography - where people draw fears of environmental and immigration catastrophes caused by too many babies or economic and cultural collapses caused by too few.
When the U.N. Population Department (UNPD) released its 2010 Revision of World Population Prospects early in May, media headlines screamed about the 10.1 billion-people-in-90-years projection. They then dropped the subject.
But the UNPD analysts arrived at the startling number by building a controversial assumption into their numbers - projecting that, sooner or later, all the women in the world would average 2.0 children.
Population watchers such as Steven W. Mosher say that a 10.1 billion population and global 2.0 fertility rate are ludicrous.
Childbearing trends “point downward,” said Mr. Mosher, president of the Population Research Institute.
Moreover, he said, several countries have proved that fertility rates can fall extremely low “and stay there for a long time,” which would make it amazing that someday, somehow, everyone will “magically self-regulate their reproduction” to precisely the level needed to maintain a global population.
The world’s population is expected to top 7 billion later this year.
On the other side of the population divide are people who are alarmed that the UNPD’s population projections are higher than ever.
Ten billion people is a “radical shift” from previous UNPD projections, which had world population peaking around 9 billion and then leveling off, husband-and-wife academics Martha Campbell and Malcolm Potts wrote recently in “The Myth of 9 Billion” in Foreign Policy magazine.
Even 10 billion people “could do irreversible damage to the planet. Its just too many people,” they said, adding that family planning and other incentives to reduce childbearing are needed more than ever.
So what are policymakers to think of these completely opposite scenarios? Is humanity destined to overrun itself? Or is it heading toward a world where children are rare but old people are everywhere?
Two babies per woman?