An Urban's Rural View

Rethinking Malthus

Urban C Lehner
By  Urban C Lehner , Editor Emeritus
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Between 1900 and 2000, world population quadrupled but global grain production rose by five times and global industrial output by 40 times. This line of combines, harvesting a crop in Mato Grosso in Brazil, is an example of how much ag technology has changed. (DTN file photo by Chris Clayton)

Of history's great thinkers, the one most relevant to farmers and ranchers is probably the English demographer Thomas Robert Malthus. He's famous for doubting that farmers could increase food production fast enough to feed a rapidly rising population. He thought the resulting food shortages would beget famines, diseases and wars, which would eventually reduce population back to sustainable levels.

A lot has happened since Malthus first published "An Essay on the Principle of Population" in 1798 and much of it undermines his thesis. When Malthus wrote, 800 million people called planet earth home. Today 7.7 billion do. Most have enough to eat. Hunger has not been eliminated, to be sure, but that's arguably a distribution problem. Farmers produce enough to feed everyone, or close to enough; the world just doesn't get the food to everyone who needs it.

During the 15 years I've been inflicting my opinions on DTN readers, I've more than once taken a swipe at Malthus, or, to be more precise, at those who continue to advocate his theory, the neo-Malthusians. As recently as last February, I headlined a post, "Do Calls for Radical Diet Changes Repeat the Malthusian Mistake?" (…)

I don't apologize for this. I continue to think the neo-Malthusians underestimate the power of technology to keep up with the rapidly increasing demand for food, energy and other essentials of life. Nonetheless, I have come to a more nuanced view of Malthus thanks to a Teaching Company course titled "Big History: The Big Bang, Life on Earth and the Rise of Humanity." (…)

As a history major, I took a lot of history courses during my four years in Ann Arbor 50 years ago -- but never one quite like this. "Big History" is multidisciplinary. The lecturer, David Christian, is a historian but what he's teaching blends astronomy, physics, chemistry, biology, anthropology, archaeology and economics with traditional history. And talk about Big! The course begins with the universe's beginning 13 billion years ago and covers everything since in 48 lectures.

Christian changed my view of Malthus by the way he defined historical periods. What he calls the Agrarian Era began roughly 10,000 years ago with the rise of agriculture and ended in 1700. One of this period's key characteristics, Christian says, was the slow pace of technological change.

Because it was slow, the era was marked by repeated Malthusian cycles, which Christian defines as "Long cycles of economic, demographic, cultural and even political expansion, generally followed by periods of crisis; warfare; and demographic, cultural and political decline. These cycles, generally lasting several centuries, are apparent throughout the Agrarian era and were probably generated by the fact that, though there was innovation (which produced the upward swings), rates of innovation could not keep pace with rates of growth (which explains the eventual crashes)."

Christian backs this contention with population statistics showing a very long-term uptrend during the Agrarian Era but lots of crashes along the way.

By contrast, the distinguishing feature of Christian's Modern Era, the time since 1700, has been a sharp acceleration in the pace of innovation. According to Christian, between 1900 and 2000 world population quadrupled but global grain production rose by five times and global industrial output by 40 times.

By Christian's definition of the historical periods, Malthus was actually right as far as the Agrarian Era was concerned. What he failed to foresee was that in the Modern Era, which was just getting started when he wrote, the pace of technological innovation was accelerating. Not only accelerating, but accelerating so quickly that food supply would be able to keep up with population growth from 800 million to 7.7 billion.

Malthus did not live to see the sharp increase in the pace of technological innovation that took place in the 19th and 20th centuries. You have to wonder if he would have concocted his gloomy theory had he lived a century later.

It is possible, to be sure, that however fast the pace of innovation, population growth might yet eventually outpace it. This is why the neo-Malthusians haven't conceded the debate.

When the Big History course hit the market in 2008, the world's population was 6 billion something. It's already risen to 7.7 billion and some demographers think it will be 10 billion in 2050. Not only is population rising, but incomes are rising in China, India and other developing countries, generating demand for not only more food but more goods of all kinds.

"Each of the more than 6 billion humans on Earth today consumes approximately 60 times as much energy as humans of the Paleolithic era," Christian writes. "These figures suggest that the total energy consumption of our species has increased by about 60,000 times in 10,000 years."

To Christian, then, there's a "real threat" of a Malthusian crisis in our future. But there's also increasing awareness of the dangers and some encouraging trends. Population growth rates are actually slowing. Ecological awareness is increasing.

"And of course," he writes, "we should not forget 'collective learning.' The collective brain of modern humanity, magnified by billions of networked computers, is the most powerful problem-solving entity we know of. If there's a solution to the problems that face us and the biosphere, 6 billion networked humans are surely likely to find it."

Urban Lehner can be reached at



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