It seems obvious that the world is headed for a food and energy crisis because of the world's large and growing human population.

In the past 100 years, the global population has gone from about 1.6 billion to approximately 6.6 billion. Given the sheer numbers, and given how much of the planet humans already use to live and eat, it's just plain common sense to see that the world can't possibly take on more and more people.

But often, what seems obvious is what you have to scrutinize the most.

Poor track record

Today's prophets of overpopulation might very well be right. But the track record of their predecessors is not that good. Take this article excerpt I found on the web site for the Committee for a Constructive Tomorrow:

In the Fifth Century, B.C., Han Fei-Tzu said the idea of
having five sons apiece was disastrous because he feared it meant
dividing limited wealth among more people.

In the Second Century, A.D., Christian theologian Tertullian
lamented about what he termed the world's "teeming" population
and concluded with certainty that "our numbers are burdensome to
the world, which can hardly support us."

St. Jerome, some 200 years later, affirmed with great
conviction, "the world is already full, and the population is too
large for the soil."

By the Eighteenth Century, English Reverend Thomas Robert
Malthus was so concerned about overpopulation that he wrote a
now-famous essay predicting imminent and catastrophic food
shortages.

And in 1968, Paul Ehrlich wrote in The Population Bomb that
the battle to feed humanity was over and predicted 65 million
Americans would die of starvation by the mid-1980's.

Not. Good.

According to some demographers, the common assumption that we are headed for a population catastrophe is based on false premises.

According to Nicholas Eberstadt's article "Population Sense and Nonsense", there are four major assumptions made by those see population growth as a looming catastrophe:

The first holds that we are self-evidently in the midst of a world population crisis...The second premise is that current rates of world population growth are not only unsustainable over the long term, but are having direct and immediate adverse repercussions on living standards, resource availability, and political stability. The third premise implicit in the agenda of "stabilizing human population" is that reduced birth rates constitute the solution to the population problems...The fourth premise bolstering this agenda is the presumption that well-placed decision-makers can effectively and expeditiously engineer the desired changes in worldwide population patterns...All of these premises are highly problematic. None of them is self-evidently true. Indeed, to the extent that any of these are testable, it would appear that they are demonstrably false.

Eberstadt also argues that population crash prophets have always underestimated the capacity for human innovation. For example, Thomas Malthus, writing in the late 18th century, couldn't have predicted the advances in agriculture that have made crop yields much more substantial than they were in his time.

Again, Eberstadt:

In a physical sense, the natural resources of the planet are clearly finite and therefore limited. But the planet is now experiencing a monumental expansion of human resources. And unlike natural resources, human resources are in practice renewable and in theory inexhaustible--indeed, it is not at all evident that there are any "natural" limits to the buildup of such potentially productive human-based capabilities.

It is in ignoring these very human resources that so many contemporary surveyors of the global prospect have so signally misjudged the demographic and environmental constraints upon development today--and equally misjudged the possibilities for tomorrow.

A Complex Equation

This isn't to say we shouldn't listen carefully to those worried about overpopulation. Today we are clearly using far -- far -- more resources on a global scale than we ever have before. We also have more advanced tools to understand our impact on the world then we did in the time of Malthus, or even when Paul Ehrlich was writing The Population Bomb in the 1960s.

And while the boy who cried wolf was shown to be wrong again and again, eventually a wolf did show up and destroy the flock.

But what we cannot do is assume that a looming population crisis is self-evident. People have confidently made that assumption in the past and were clearly wrong.

The relationship between population and the environment is a complex one involving a number of variables.

We do have to be concerned about a growing human population's effect on the planet. But we must never lose sight of the complexity of the issue. And we must never take dire predictions of population catastrophe at face value.