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What an 18th century treatise on population can teach us about energy resources

The views expressed are those of the author and are not necessarily those of Scientific American.

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A several hundred year old treatise on human population offers insight into understanding energy resources.

Thomas Malthus

In 1798, a fellow by the name of Thomas Malthus predicted what he believed to be impending doom for the human race. By his calculations, the human race was outpacing its ability to produce food for itself. Malthus, a British scholar and economist, figured that a single acre of cropland would only increase yields by some small percentage each year. Humans, on the other hand, would double their population every hundred years or so. In his treatise, “An Essay on the Principle of Population”, Malthus formalized his portent of cataclysmic famine by stating “the power of population, is so superior to the power of the earth to produce subsistence from man, that premature death must in some shape or other visit the human race.” This “premature death”, by Matlhus’ reasoning, would occur midway through the 1800s.

As we know, Malthus’ prediction didn’t come true. Human kind didn’t succumb to a massive famine. From the time of his writing in 1798 to the mid-1800s, the global planet gained 100 million people, bringing the total to well over a billion people. New croplands were cultivated in the newly explored United States, rich in land and nutrients, helping to feed a growing world population.

World population increased over sixfold from 1800 through 2000.

But then something happened midway through the 20th century: population exploded. The number of people passed the 3 billion mark sometime in the 1960s, and crossed the 6 billion mark at the turn of the millennium. The reason? A new technological advance revolutionized modern agriculture: fertilizers. By pulling nitrogen out of the air in seemingly unlimited quantities, farmers could overcome the natural nutrient limitations in crop land and produce more food. No longer bound to natural limitations of agriculture, more calories could be supplied, which in turn, resulted in more people.

There are strong parallels to the growth of modern agriculture to the story of modern energy resources. New scientific and engineering advancements are challenging previously held beliefs about the world’s energy supplies. Developments such as horizontal drilling and hydraulic fracturing are unlocking previously unattainable oil and natural gas resources, essentially “feeding” a growing planet.


In the 1950s, a geologist at Shell Oil Company named M. King Hubbert proposed that humankind would run up against natural limits in terms of available oil reserves. By Hubbert’s calculations, humankind was consuming oil at a rate faster than it was being replenished by natural processes. By doing so, a peak in oil production was inevitable: the early 1970s for U.S. production, around the year 2000 for global production.

Hubbert’s peak projected that global crude oil production would peak around the turn of the millennium. Courtesy of Cornell University.

To his credit, Hubbert was essentially spot on with his U.S. estimate, which expected U.S. oil production to peak in the early 1970s and decline in following decades (coincidentally, the same holds true for Texas oil production). His estimates for a global peak, however, have not come true.

While useful at the time, if anything, to reinforce the idea of rates, Hubbert’s peak has grossly underestimated the world’s recoverable oil resources. Like Malthus before him in the 18th century, Hubbert’s estimate leaves out advancements in extraction technologies that have led to record global oil production levels, among other considerations. According to data from British Petroleum’s 2012 Statistical Review, global oil production exceed 83 million barrels per day, fueled in large part by domestic U.S. production. Most estimates expect global energy demand to continue, along with oil production (at least through the middle of this century).

Global oil production has continued to increase, aided by high demand and technological advances such as horizontal drilling and hydraulic fracturing.

At some point, however, no addition of technological advances will result in more natural oil production because of the previously mentioned timescales (which is why biofuels are particularly interesting because we can essentially fast forward millions of years of heat and pressure). We will essentially reach the top of the “S curve” for oil production, and by that time, it’s reasonable to assume that a substitute for oil will be available, which poses far more interesting questions: what will the new resources be, and what will be the triggers that initiate a shift?

As we have learned with the modern food economy, natural limits of energy resources must ultimately be respected, but so must technological advances.

David Wogan About the Author: An engineer and policy researcher who writes about energy, technology, and policy - and everything in between. Based in Austin, Texas. Comments? Follow on Twitter @davidwogan.

The views expressed are those of the author and are not necessarily those of Scientific American.

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  1. 1. ronwagn 9:44 pm 03/26/2013

    Don’t forget about natural gas, which has far more potential than oil ever did. Think methane hydrates which have an estimated ten times all land based natural gas.

    Natural gas is the future of energy. It is replacing dirty old coal plants, and dangerous expensive nuclear plants. It will fuel cars, trucks, vans, buses, locomotives, aircraft, ships, tractors, engines of all kinds. It costs far less. It will help keep us out of more useless wars, where we shed our blood and money. It is used to make many products. It will bring jobs and boost our economy. It lowers CO2 emissions, and pollution. Over 5,800 select natural gas story links on my free blog. An annotated and illustrated bibliography of live links, updated daily. The worldwide picture of natural gas. Read in 77 nations. ronwagnersrants . blogspot . com

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  2. 2. M Tucker 4:03 pm 03/27/2013

    US oil production does not take in account the unconventional tar sand oil from Canada and the heavy oil from Venezuela. Most estimates I have seen indicate reserves to easily last through this century. BUT, that oil is not cheap. It carries a high economic and energy cost to recover (besides the environmental cost). Food and oil will be much more expensive this century.

    “…premature death must in some shape or other visit the human race.” For Malthus that also meant illness. Well starvation and illness has been with the human race from the beginning and it has been with us from the 18th century straight through to this very day. The human race has so far survived them all while steadily increasing population. Certainly many more will be added to the list of the poor and starving, certainly it may become harder to afford food in wealthy countries, it may even become impossible to afford gasoline from conventional and unconventional oil, certainly science promises that we will again see a pandemic like the 1918-1919 influenza, but it will take something amazingly unprecedented to cause world population to actually fall. None of the pandemics and famines the world has seen since Malthus made his prediction has caused world population to fall. Maybe an increase in average global temperature above 2 deg C sparking multi-year droughts and repeated 100 year, 500 year, and 1000 years weather catastrophes coming every 3 to 5 years? Maybe that will do it?

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  3. 3. Germanicus 8:24 am 03/29/2013

    Optimism is justified only if major terms in the equation retain their values…if not, calamity swift & sure… absent drastic decarbonization, demographic collapse seems ineluctable…no disembodied cosmic force or deus ex machina can save us.

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  4. 4. Sneemaster 2:11 pm 03/30/2013

    Good Ol’ Malthus. Proven wrong for quite some time now, yet his treatise offers us additional valuable insights.
    OK now.

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  5. 5. N a g n o s t i c 2:17 pm 03/30/2013

    I do know valuable insights can be had from a great number of past intellects, great and small. Much of their work is ignored by many at any given time, unfortunately.

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  6. 6. N a g n o s t i c 2:19 pm 03/30/2013

    I have no clue how my post referring to “Good Ol’ Malthus” got tagged “Sneemaster”.

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  7. 7. sault 5:53 pm 04/1/2013


    Quit copying and pasting from your unprofessional blog. You are not adding anything to these discussions except for gas company propaganda.

    While advances like nitrogen fertilizer and horizontal “fracking” can extend the lifetime of unsustainable practices for a short while, they do not alter the underlying, fundamental forces at work, so these processes eventually come crashing to a halt. And since every time we move farther and farther away from natural processes to get stuff we need, it takes more energy and effort to produce those things, these processes become ever more expensive and inefficient on their way towards that crash. Just like fracking takes more energy to extract a barrel of oil or a cubic meter of gas, trying to maintain these nonrenewable processes will goble up more and more of our energy and wealth on our way down the Hubbert Curve.

    Regardless of what the fossil fuel companies would like you to believe (and copy / paste onto as many comment boards as possible apparently…), their business model is increasingly becoming outdated, both by the depleting resources they extract and the clean energy alternatives that offer a better future for humanity. And to stave off the worst effects of climate change, we will need to leave most of the world’s remaining fossil fuel reserves in the ground. It IS the cheapest form of carbon sequestration after all.

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