Subway stations post stern warnings about getting near the tracks not only because one might get run over, but also because those tracks often include an exposed, electrified third rail that powers the subway trains. That fact has given birth to a common metaphor in the United States where it is often said that the U. S. Social Security system is the third rail of American politics; touch it and you die. Politically, that is.

But there is another broader issue that seems to have become the third rail for world politics: overpopulation. This week in an astounding piece in USA Today, the newspaper told us that U. S. fertility rates had returned to the replacement value of 2.1 (that is, 2.1 births per woman on average) after being below replacement since 1971. This was deemed good because “[a] high fertility rate is important to industrialized nations. When birthrates are low, there are fewer people to fill jobs and support the elderly.” Ergo, the low fertility rates of Italy, Germany, Japan, Russia, and South Korea (all mentioned in the article) must be bad. These countries were said to be “struggling with low birthrates and aging populations.” In fact, some of these low fertility countries are now providing government incentives for larger families.

Within the narrow measures of economic competitiveness and public pension support for the elderly the labels of good and bad might be applicable. But what about the environmental degradation and resource depletion that are resulting from overpopulation in these very same countries? Not a single word!

Is there any explanation for this glaring omission? Probably, there are many. But one explanation is sticking in my mind. The explanation comes courtesy of Albert Barlett, the retired University of Colorado physics professor who has spent his retirement warning the world about the dangers of exponential growth. Barlett reminds us in a recently published essay included in an anthology entitled The Future of Sustainability that carrying capacity can be imported from other countries. That means that the damage resulting from overpopulation in the countries mentioned in the article is not always visible within those countries. Only Russia, for example, is self-sufficient in energy. And, Russia, Japan and South Korea must import considerable amounts of food. Much of the raw material for the factories in all the countries mentioned is imported from other countries, mostly so-called developing countries, from their mines, their fields, their fisheries and their forests.

So it is no wonder that the reporters at USA Today didn’t notice the deleterious effects of overpopulation on these so-called industrialized nations. As those countries import carrying capacity, they also export environmental degradation and resource depletion. Everything looks fine to most people in the importing nations. For example, while Japanese consumers are helping to strip the world of its remaining forests, the country preserves its own forests and enjoys a forest cover of around 67 percent.

The damage does, however, show up on the evening news as a conflict in some distant, dusty country where forests are being leveled and rivers are being drained. The conflict is usually put down to some ethnic or religious rivalry. Often a quick recap of the last few centuries of history in such places is provided for the sole purpose of proving that “these people have never gotten along.”

Even if some politicians, policymakers and reporters in wealthy countries can see beyond the daily mirage of plenty to the overpopulation problem, they do not want to touch it. Those who advocate for measures to reduce population often find themselves accused of one or more of the following motivations: 1) a desire to kill the old and the infirm, 2) a desire to force people to have abortions, 3) a desire to prevent poor countries from achieving political and military power, 4) a genocidal mania aimed at reducing the population of certain minorities, and 5) a pathological attachment to animals and nature coupled with a desire to preserve the world for nonhumans. I can tell you from personal experience that it doesn’t really matter how many times you say the word “voluntary” in front of the words “family planning,” you will still be under suspicion.

Of course, those wishing to avoid all taint of unsavory or paranoid accusations will simply call you “anti-growth.” This automatically makes you an enemy of the poor who will have no hope of bettering themselves under your plan for population reduction. If you answer this charge by suggesting that perhaps we should redistribute the world’s wealth more equitably while simultaneously reducing population, they will call you a “socialist” if they are trying to be polite or a “communist” if aren’t.

One thing you can be sure of. No defensible ecological argument will be made to refute you.

It is not obvious to me how to change the discourse on population. I usually avoid it in my initial discussions with people about our ecological predicament. If someone asks about population during a question and answer session, I respond as well as I can. Sometimes a well-informed questioner surmises that I simply must understand the connection between overpopulation and our environmental and resource problems. Such a questioner will phrase his or her query this way: “How come you didn’t talk about overpopulation? That’s at the root of all our problems.”

Well, now I can refer those questioners to this piece.