Human Population Decline? Not Fast Enough

According to David Reher, a population historian at the Universidad Complutense de Madrid, "historically, a 'large and well-nourished population' has always been considered the sign of a successful society and a successful economy. The very idea of decline and of population shortage is largely foreign to our society, mostly because for several centuries there has been no experience of shrinking population."

But, he says, there are several signs that global human population is heading into decline, after two hundred years of unstoppable growth. National fertility rates are dropping nearly everywhere in the world. Women's roles are changing. The processes of modernization have tipped the cost-benefit ratio of having large families, making them uneconomic, especially in urban settings.



"Times of flux are not times that are conducive to optimism about the future," Reher says. "Having children is ultimately an expression of confidence in the future; in the security of the life you can expect your children to be able to lead."

"For our children, and especially our grandchildren, persistent population decline — and possibly lower living standards — will likely be the only reality they will ever experience and the times of runaway population growth so prevalent in the nineteenth and twentieth centuries will be but a distant memory of the past."

"Periods of decline," Reher explains, "have been equated to decadence and to societies that were somehow unable to function properly." He goes on to say that this is "a time of deepening concern about the sustainability of society as we know it."

But global population decline isn't happening fast enough to make a difference in our negative impact on the planet.

In 1989, Jean Bourgeois-Pichat, a renowned French demographer, suggested that "… l’humanité part de zéro, il y a quelque 600 000 ans, et y retourne vers l’an 2400" (humanity started from nothing 600,000 years ago, and will return to nothing around the year 2400). Perhaps Bourgeois-Pichat was factoring global warming into his population projections?

It will be sooner now, however, with the latest climate change research added in. If global overheating is left unchecked (because we don't make the necessary transition to a renewable energy economy fast enough), by 2100 most species on Earth will be condemned to eventual extinction — homo sapiens being no exception.


[Reher's paper, Long-term population decline, past and future, was presented at the 2005 International Union for the Scientific Study of Population Conference in Tours, France.