Population GrowthAndreus: DreamstimeUniversity of Maryland professor of geography and environmental systems Erle Ellis published a splendidly lucid op/ed, "Overpopulation Is Not The Problem," in Saturday's New York Times. Neo-Malthusian pronouncements have been a staple of ideological environmentalism for more than 40 years.

Back in 1968, Stanford University biologist Paul Ehrlich flatly predicted in his doomy screed The Population Bomb that the “battle to feed humanity is over. In the 1970s, the world will undergo famines. Hundreds of millions of people are going to starve to death in spite of any crash programs embarked upon now.” Just back in January of this year famed nature documentarian Sir David Attenborough declared, “We are a plague upon the earth. ... Either we limit our population growth or the natural world will do it for us.”

Yet population doom has stubbornly failed to arrive as predicted. In his op/ed Ellis explains why so many biologists and environmentalists have gotten everything so wrong:

MANY scientists believe that by transforming the earth’s natural landscapes, we are undermining the very life support systems that sustain us. Like bacteria in a petri dish, our exploding numbers are reaching the limits of a finite planet, with dire consequences. Disaster looms as humans exceed the earth’s natural carrying capacity. Clearly, this could not be sustainable.

This is nonsense. Even today, I hear some of my scientific colleagues repeat these and similar claims — often unchallenged. And once, I too believed them. Yet these claims demonstrate a profound misunderstanding of the ecology of human systems. The conditions that sustain humanity are not natural and never have been. Since prehistory, human populations have used technologies and engineered ecosystems to sustain populations well beyond the capabilities of unaltered “natural” ecosystems.

Ellis explains something that has long been clear to those not steeped in the simplistic verities of population biology: People confronted with scarcities don't just lay there and die; they make more resources, i.e., they expand carrying capacity.

Elllis continues:

The world population is now estimated at 7.2 billion. But with current industrial technologies, the Food and Agriculture Organization of the United Nations has estimated that the more than nine billion people expected by 2050 as the population nears its peak could be supported as long as necessary investments in infrastructure and conducive trade, anti-poverty and food security policies are in place. Who knows what will be possible with the technologies of the future? The important message from these rough numbers should be clear. There really is no such thing as a human carrying capacity. We are nothing at all like bacteria in a petri dish.

Why is it that highly trained natural scientists don’t understand this? My experience is likely to be illustrative. Trained as a biologist, I learned the classic mathematics of population growth — that populations must have their limits and must ultimately reach a balance with their environments. Not to think so would be to misunderstand physics: there is only one earth, of course!

It was only after years of research into the ecology of agriculture in China that I reached the point where my observations forced me to see beyond my biologists’s blinders. Unable to explain how populations grew for millenniums while increasing the productivity of the same land, I discovered the agricultural economist Ester Boserup, the antidote to the demographer and economist Thomas Malthus and his theory that population growth tends to outrun the food supply. Her theories of population growth as a driver of land productivity explained the data I was gathering in ways that Malthus could never do. While remaining an ecologist, I became a fellow traveler with those who directly study long-term human-environment relationships — archaeologists, geographers, environmental historians and agricultural economists.

The science of human sustenance is inherently a social science. Neither physics nor chemistry nor even biology is adequate to understand how it has been possible for one species to reshape both its own future and the destiny of an entire planet. This is the science of the Anthropocene. The idea that humans must live within the natural environmental limits of our planet denies the realities of our entire history, and most likely the future. Humans are niche creators. We transform ecosystems to sustain ourselves. This is what we do and have always done. Our planet’s human-carrying capacity emerges from the capabilities of our social systems and our technologies more than from any environmental limits.

Actually, as I argued in my column, "Free Markets = Sustainable Development," the social science behind increasing human sustenance is the rise and expansion of free markets, strong property rights, and the rule of law.

The Ellis op/ed is well your time. Perhaps the tide of Neo-Malthusian thinking will finally ebb.