Published on July 14th, 2008 | by chrisschille


Overpopulation and Oil: What the Talking Heads Don’t Talk About

Oil Well at Sunset 

Sometime back on National Public Radio, a panel discussed the high cost of gasoline and what the next president should do about it. When asked if we should be concerned about running out of oil, a panelist quipped that “President Obama” will create appropriate tax incentives for photovoltaics and oil will become so much “useless sludge”. Am I alone in thinking that there is a general lack of understanding about what the future holds for all of us when petroleum runs out?

Yes, We Eat Oil

When nitrogen is allowed to infiltrate a suitable body of water, the normal population of algae grows explosively. It consumes available nutrients and oxygen, turns the water green, and kills most other species. The algae, unable to thrive under the conditions they themselves have created, begin to die. This is called an algae bloom.

Petroleum is humanity’s source of nitrogen. Increasingly, we’re aware that it doesn’t just heat our houses and propel our cars; we actually eat it. Through the twin miracles of modern agriculture and wet-milling, petroleum becomes nitrogen fertilizer, which becomes corn or soybeans, which become virtually every and any processed food product we know (including virtually all meat and farmed fish).[1] In Michael Pollan’s acclaimed book The Omnivore’s Dilemma, he documents that over sixty percent of the average American’s diet comes from (petroleum-derived) corn![2]

Why Do We Eat Oil?

It’s petroleum that allows one farmer to feed ten thousand people. After all this time, it still costs less than a dollar to pump a barrel of oil out of the ground. Cheap petroleum gave rise to an a sustained era of over-producing food, which led to an explosion in world population. With any luck, petroleum will run out before we complete our algae-like “bloom” cycle.

Too Many People on Earth

Global climate change, dwindling aquifers, the accelerated loss of species and habitat are symptoms of a bigger disease: human overpopulation. How do we know this? For one, simple arithmetic. If you take the entire area of the earth’s surface, subtract out oceans, deserts, and extreme latitudes, and divide the result by six billion people (our current population), you get about four acres of habitable land per human, of which approximately two are suitable for growing food. The debate, then, is about whether a few acres is enough to sustain each of us — that is, without petroleum.

Most people frame the issue in terms of carrying capacity.  Some estimates for the carrying capacity of our planet range between eight-hundred million and eight billion people. (Actually, estimates vary more widely because determining what humans need, want, and then actually use, is non-trivial.) The lower number reflects the notion that there is not just a physical carrying capacity, but a social carrying capacity for the planet, which takes into account issues of competition, free will, and so forth (“human nature”).

If you ask a person on the street, likely they’ll tell you that Earth’s carrying capacity is around, or somewhat above, our current population. In other words, most folks assume that there is always room for a few more of us.  I’d argue that we’ve already way overshot the mark.

Smallest Footprint Too Big

Is the lower number more realistic? I’ve met a number of people who’ve attempted self-sufficiency on ten, twenty, and even forty acre properties. Not for lack of ability or effort, but no one was successful: all were dependent on some amount of petroleum and petroleum-manufactured goods. Observation and personal experience has led me to believe that estimates for sustainable footprints are low, chiefly because they ignore a dependence on fossil fuel energy, which will have to be made up by wood and other sources of fuel.  These require additional acreage to produce. Consider that without access to oil or coal, the Romans denuded much of Italy’s forests making cement and smelting steel.

What About Solar?

Solar technologies (photovoltaic, wind, hydro, and solar-thermal) are vital.[3] However, they’re not a replacement for petroleum. If you think about it, petroleum is just another form of solar energy. Ignoring the time period and the process by which it was actually formed, petroleum represents stored solar energy equivalent to a significant fraction of all the sun’s energy that struck the Earth for hundreds of years. The trouble is that we’ve gone through virtually all this energy in the last few decades. (Ever had a cell phone that used more power than the battery charger could feed to it? Once dead, even plugged in, it will make no more calls for a while.)

Even with solar cells on every roof, we still can’t sustain our current population without petroleum. We can’t imagine what it will be like to run out of oil.

What Does ‘Decimation’ Mean?

Does recorded history offer any examples of large human populations faced with this level of stress? “Lesser” examples abound right now: competition for limited resources in areas like Somalia, Zimbabwe, Ethiopia, Palestine, and Iraq, to name a few. (It’s said that all wars, directly or indirectly, are about competition for resources.) I don’t mean to trivialize the suffering and upheaval in this places, but consider: at a carrying capacity number of eight-hundred million for our planet, and if we grow to eight billion by the time we effectively run out of oil, today’s most pressing issue is that we need to reduce our population by ninety percent! The definition of ‘decimation’, by contrast, is only to reduce by one-tenth.

If we face anything like this “reduction”, it’s hard to imagine that civil government — and modern economies — wouldn’t collapse, along with all the good stuff that comes with them: the ability to preserve the natural world and its species; art, culture, technology, and wealth.

The Money’s Gone!

If a common concern for most humans is (monetary) wealth, then consider: virtually all wealth as we know it is directly or indirectly petroleum-derived. Even were that not the case, its still hard to imagine that currencies and other vital trappings of an economy can survive when a majority of the population doesn’t. Even economic theory seems to depend on stable, growing populations.

Birth Control?

Theoretically, we might be able to achieve drastic population reduction through less chaotic means, through some form of birth control. Call me a skeptic if you will, but I can’t see getting the consensus needed to make this happen.

Bottom Line

The fact that we are poisoning our planet and ourselves finally has everyone’s attention. What we address now may determine what, if anything, we leave our grandchildren. Nevertheless, the scarier problem facing all of us is this: if we are significantly above the planet’s carrying capacity, our population must, and will, shrink dramatically.

It seems that very few people believe population pressure poses such an urgent problem. If overpopulation doesn’t trump all the other problems facing us, I’d like to know why.


[1]Wet-milling refers to processing that breaks up cereal grains into all manner of industrial components much the way petroleum is “cracked” to produce everything from petroleum jelly to solvents.

[2]Carbon atoms from corn have a distinct signature that allow them to be tracked from corn plant to human and animal consumers.  A piece of human hair, for example, can be analyzed to determine the amount of corn in an individual’s diet.   Industrial-scale farming rotates soybeans and corn; industrial consumers use whichever is cheaper.  This is the meaning behind food labels like “contains corn and/or soybean oil”.  Both are feedstock for wet-milling, but only corn has a traceable carbon signature.

[3]The sun heating air creates wind.  Water is evaporated and mobilized by the sun to higher elevations; hydro-electric power generation harnesses this energy.

Related Articles

When Sex Isn’t Sexy…Environmental Implications of Another Baby Boom

Sources and Recommended Links

Film: Crude Awakening
Book: The Omnivore’s Dilemma, by Michael Pollan.

Photo Credit: Sasha Burkhard –

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  • one word: nanosolar

    solar power significantly cheaper than coal changes the whole equation – if you’re interested, I can write up roughly how, but the basics are here:

    Hi Vinay,
    Thanks for your comment. I worry about having the energy (in the future) to manufacture solar panels, cell phones, and the like. Right now, the energy to manufacture these devices comes from fossil fuel. It could be that we will discover how to create solar panels made from bamboo and chlorophyll. Personally, I think the low-embodied-energy devices to which we’ll be limited to in the future will incorporate some decidedly low-tech elements.

  • Mason Hamilton

    Topically your article is very much on target. The specifics (numbers) are lacking to make your content more impactful, which should be available. It doesn’t take much to figure out food production based on nitrogen fertilizer (95% made from petroleum) is going limit population one way or another. Solar and wind power (even if deployed successfully in time) will have little affect on this aspect of over population. Unfortunately, no one wants to hear or talk about over population or it being the primary driver for the energy and the food crisis. The only good news (that’s relative to starvation) is the Chinese model of dealing with population legislation and harshful enforcement did work. The bad news is that is that (as you point out) capitalism will not work on declining populations and markets. One way or another our world is going to change a lot in the near future.

    Thanks, Mason. I’d welcome any links to supporting (or refuting) data.

    I was thinking of the Chinese model for dealing with the population issue. I hate to even bring it up, though, for fear of the backlash it would cause here in U.S. (Ever read the book Cheaper by the Dozen?)

  • Great article. I agree that the role oil plays in food is too often overlooked when discussing energy future.

    I don’t know what the world’s carrying capacity is, but it certainly depends on technology. With current technology, food, energy, and people are all competing for land and water. New technologies for energy storage and transport may open up remote desert areas or the ocean for solar and wind harvesting in the future.

    If we don’t push technological development now, there will probably be a horrible “correction” in the global population. It’s a simple scenario. Closely packed, malnourished populations are just the way to jump start emerging diseases.

    What I find fascinating is that most developed countries are now worried that their populations are shrinking. Birthrates are well below the replacement value in most fully developed nations (except the US).

    While it is vexing to me that a bunch of us are worried about over population while others are trying to figure out how to raise birth rates, it is a promising development. Perhaps the population growth might correct itself before it’s too late.

    Again, what we need is technology. The technology to bring the “modern” world to the developing world without bringing the oil.

    You make great points. It’s ironic that some countries worry about declining birthrates, isn’t it? At some level, it may be an expression of competition.

    It’s a fact that if our population is too large and we don’t address it through birth control, and we somehow manage to avoid killing each other through war, as you said, we just set ourselves up to be destroyed by disease. It’s almost a shame the term “green-house effect” refers to heat and gas build-up; it’s a powerful metaphor for the vulnerability of extremely dense populations of a single species. (Another metaphor that comes to mind is fire suppression.)

  • GMoney

    Thank You for writing this. This has to find it’s way into mainstream conscience. I wrote about the peak oil crisis years ago, and I was dismissed as a loon, that gas would never go above 3 dollars a gallon. Now the government and the rich are telling people ” Don’t panic, solar will power everything before we run out of oil.”

    If I was rich, I would buy one of the missile silos in Kansas, build or enhance a 40 acre area around it(heavily fortified). I would stock (underground) 20,000 galllons of fuel, 2,000 bags of fertilizer and products for agriculture, 2,000 emergency MRE meals, and a god awful array of weaponry to fight off any onslaught. I would also have underground storage for 50,000 gallons of water, a couple small fuel efficient tractors, with spare parts to keep them running for 20 years. Windmill, generators, some solar panels, etc.

    I wouldn’t live there, it would just be the place I could run to in case you and I are right, and sooner than later. I think that we will start to taper off naturally, as people will not be able to afford 6 kids anymore. I heard Bush complain about China subsidizing fuel, we subsidize kids, with tax breaks up the yang, and welfare that increases with each kid, no penalty for 10-15 kids, just more tax refunds. Dismiss this if you wish, but just as the oil crisis was predicted and ignored, this will come to pass. Before oil was discovered, the earth could not support over 2 billion people, and soon we will have to get back below that number, or the earth will do it for us. Famines, war, disease, are the earths way of maintaining homeostasis. The algae bloom is a good analogy, a cancer is another. We are the earth’s cancer, consuming it until we kill all life on it. We will kill every living thing on this planet, then we will turn on each other. The truth isn’t pretty, but that doesn’t mean it isn’t the truth.

    I really wish I could disagree with any of your points. (I can’t.)

  • John Smith

    You should start the decimation by killing yourself.

  • Infogleaner

    My eye caught the algae bloom comment. I’m a big proponent of algae as a source of fuel. This sight is a good start:

    In it, they claim incredible yields:

    Yield of Various Plant Oils

    Crop Oil in Liters per hectare
    Castor 1413
    Sunflower 952
    Safflower 779
    Palm 5950
    Soy 446
    Coconut 2689
    Algae 100000

    If we can squeeze that much oil out of algae, we can afford to keep the die-off at a minimum for the human race.

    Bottom line, the poorest will get the worst(viz. parts of Africa), while the rich may suffer at most an inconvenience.

    Algae-derived biofuels stand a good chance of being a very important part of our future. As you point out, they have great yield potential, and it’s hard to beat oily hydrocarbons for fuel density. On the flip side, we still have to make biofuels, versus having hundreds or even thousands of years’ worth of production stockpiled for our use before we got here (in the case of petroleum). For this reason, I think they’ll a replacement for oil, but not _the_ replacement for oil. Good comment.

  • So, exactly which people do you want to have fewer children? Do YOU have too many children??? Western children are much more of a drain on resources than deep African kids are, so are your children the problem?

    The problem has nothing to do with population at all. The problem is GREED. Selfish dictators living like Gods while others starve, the rich over-lords burning out farmers who speak against them, and huge corporations deeply invested in GM seed production.

    Stop pointing the finger at every other ethnic or religious group for having too many children and start pointing the finger at the super greedy. They cause the hunger, they commit the waste, and they murder humans and anything else that gets in their way of profit.

  • Rockymtnway

    Excellent article, but as noted, most folks won’t read it or get it because it doesn’t end with “don’t worry, you don’t have to change anything; technology will save you.” I’ve worked in psychology for years and the fact is people don’t change behaviors without painful stimuli as motivation. Nobody wakes up when their life is going well and says, “my life is so great, I’m going to change everything.” We cling to the comfortable even when it kills us. The alcoholic won’t stop drinking until they hit rock bottom; the world won’t stop using oil until they can’t afford a drink at the tap anymore.

    The good news is that gas is finally $4.00+ per gallon in the US. If we taxed it to the actual expense for infrastructure, it would have been $8-10/gallon years ago like the Europeans have been paying. However, even that isn’t enough when we should also be taxing it appropriate to the environmental and climatalogical costs. But as you mention, that’s only part of the problem. Even if we all cut our fuel consumption by 75% in the next 20 years, there’s still just too many humans on this planet.

    Personally, I don’t see things going well in the next 20 years, but look at the bright side. Maybe $4.50/gallon is equal to an alcoholic’s DUI arrest. Following that logic, the economic collapse equivelent to the Great Depression yielding 25% or greater unemployment would be a tremendous curb to the consumption of natural resources would be the nasty divorce. The war over resources (first Iraq, then Iran, then China?) is like the first domestic violence arrest. Maybe at some point we’ll check into Oilhaulics Anonymous… or we’ll proceed to crash the car headlong into oncoming traffic and involuntarily kill all the passengers traveling with us (nuclear war). In any case, Mission Accomplished… we all knows what that means (fighting to continue until further notice).

    Listen, I’m not trying to be depressing, but sometimes an article like this gets me to wondering why we try? I know from my experience in psychology, no matter what, this isn’t going to end well for our species. I do my part not because I’m some great enviro, but because I think I can live well without a giant SUV, big house, or half-dozen rug-rats and find the simplicity improves rather than impedes my quality of life. However, who am I to tell my friend with the 12mpg SUV to stop now? I know that as a species, we won’t fix the problem until the pain of our ways exceeds our desire to cling to what has always given us comfort.

    A strong motivation for writing this article was to see what rational, thoughtful people had to say on this topic. The good news is that it worked; the bad news is that, apparently, I’m not alone with many conclusions. Thanks for a great comment.

  • joe_L

    Energy is a biggest problem and nobody is addressing it directly……….long term solutions are to late……..we need an immediate solution while the long term plans are working………the US is the largest agricultural producer in the world……..we need to place an export tax on all agricultural products and use the income to subsidize the price of gas at the pump………OPEC subsidizes the price of gas at the pump. Iraq pays Kuwait 5% of all oil revenues for war damages.We have been paying Iraq for the past 15 years for having troops there…..are our elected officials stupid………….Kuwait want us to pay 450 million for fuel we used while we were fighting to retake their country………We need to collect the monies owed us from WWI & WWII……..we have 29,000 troops in Korea when S Korea is trading with the north and S Korean tourist are going north……..what wrong here……….I could write for days on the military waste and lost money our elected officials don’t try to collect…………….

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