Too many people? Too few? How about more imagination?

#182945762 / gettyimages.com

Painting on the Mexican side of the U.S. border wall.

While looking for something else, I just ran across some musings about a couple of books written by Elizabeth Kolbert last fall in the New Yorker. First up, she summarizes Alan Weisman's Countdown: Our Last, Best Hope for a Future on Earth? Weisman argues that the only hope for humanity is to find a way to reduce our numbers and hence our impact on natural systems.

The alternative to an orderly global “countdown” is, he warns, pretty dire. “Whether we accept it or not, this will likely be the century that determines what the optimal human population is for our planet,” he writes. “Either we decide to manage our own numbers, to avoid a collision of every line on civilization’s graph—or nature will do it for us.”

Getting there requires a Total Fertility Rate (TFR) that is less than replacement level. Replacement level is a little over 2. Europe more than achieves this as does China through the one child policy. Japan's TFR at 1.4 has led to population decline. The U.S. sits right about at the replacement threshold. But -- and this is stunning -- in much of Africa the TFR is over 5 and people see nothing but good in this. Nigeria at 5.3 TFR is expected to have more people than the United States in a couple of decades.

Weisman is, understandably, trying to figure out how we could have less people; Kolbert goes on to highlight a book by Steven Philip Kramer, from the National Defense University, The Other Population Crisis: What Governments Can Do About Falling Birth Rates. Modern developed countries have built social systems that won't work if the supply of young people does not keep pace with length of life.

Kramer argues that countries like Singapore and Italy, where the fertility rate has dropped below replacement levels, are in deep trouble. As their populations age and ultimately shrink, low-fertility countries will have fewer and fewer workers supporting more and more retirees. This will strain their social-welfare systems. To compound the problem, young people, Kramer says, tend “to be in the vanguard of technological innovation,” so aging countries may suffer from a sort of app gap.

There's lots more and it is more subtle than I've indicated -- read all of Kolbert's article here.

But first, ponder this for a moment: don't these two parallel laments suggest their own solution, at least in part? We have too many people for health of the planet but some people in less well off places keep making too many more people, presumably because more children help make life better for families that are poor. Meanwhile the rich places don't have enough young people to sustain our social arrangements.

Come on, think a minute. We live in a time when capital is global, when communication is global, when information goes everywhere -- maybe it is time for people also to be able to go everywhere? Maybe Europe and Japan need some of those Nigerians? The U.S. actually sustains its population growth in precisely this manner -- it is not the long time residents who are keeping us at about 2 TFR; it is the new immigrants.

Yes -- this solution presents all sorts of challenges of clashing lifestyles, histories and cultures. It is not how humans have typically behaved; we seem programmed to fight, not to share. But we already more and more know we're on the planet together. To go back to how Weisman speaks about this: maybe this is the century in which humanity will solve some of our problems by distributing the species more evenly across the globe? We may have to.