Why Malthus Got His Forecast Wrong

Most of us have heard that Thomas Malthus made a forecast in 1798 that the world would run short of food. He expected that this would happen because in a world with limited agricultural land, food supply would fail to rise as rapidly as population. In fact, at the time of his writing, he believed that population was already in danger of outstripping food supply. As a result, he expected that a great famine would ensue.

Most of us don’t understand why he was wrong. A common misbelief is that the reason he was wrong is that he failed to anticipate improved technology. My analysis suggests that there were really two underlying factors which enabled the development and widespread use of technology. These were (1) the beginning of fossil fuel use, which ramped up immediately after his writing, and (2) a ramp up in non-governmental debt after World War II, which enabled the rapid uptake of new technology such as the sale of cars and trucks. Without fossil fuels, availability of  materials such as metal and glass (needed for most types of technology) would have been severely restricted. Without increased debt, common people would not have been able to afford the new types of high-tech products that businesses were able to produce.

This issue of why Malthus’s forecast was wrong is relevant today, as we grapple with the issues of world hunger and of oil consumption that is not growing as rapidly as consumers would like–certainly it is not keeping oil prices down at historic levels.

What Malthus Didn’t Anticipate

Malthus was writing immediately before fossil fuel use started to ramp up.

Figure 1. World Energy Consumption by Source, Based on Vaclav Smil estimates from Energy Transitions: History, Requirements and Prospects and together with BP Statistical Data on 1965 and subsequent

Figure 1. World Energy Consumption by Source, Based on Vaclav Smil estimates from Energy Transitions: History, Requirements and Prospects and together with BP Statistical Data on 1965 and subsequent

The availability of coal allowed more and better metal products (such as metal plows, barbed wire fences, and trains for long distance transport).  These and other inventions allowed the number of farmers to decrease at the same time the amount of food produced (per farmer and in total) rose. On a per capita basis, energy consumption rose (Figure 2) allowing farmers and others more efficient ways of growing crops and manufacturing goods.

Figure 2. Per capita world energy consumption, calculated by dividing world energy consumption (based on Vaclav Smil estimates from Energy Transitions: History, Requirements and Prospects together with BP Statistical Data for 1965 and subsequent) by population estimates, based on Angus Maddison data.

Figure 2. Per capita world energy consumption, calculated by dividing world energy consumption (based on Vaclav Smil estimates from Energy Transitions: History, Requirements and Prospects together with BP Statistical Data for 1965 and subsequent) by population estimates, based on Angus Maddison data.

If it hadn’t been for the fossil fuel ramp up, starting first with coal, Malthus might in fact have been right. As it was, population was able to ramp up quickly after the addition of fossil fuels.

Figure 3. World Population, based on Angus Maddison estimates, interpolated where necessary.

Figure 3. World Population, based on Angus Maddison estimates, interpolated where necessary.

A person can see that there was a particularly steep rise in population, right after World War II, in the 1950s and 1960s (Figure 3). This is when oil consumption mushroomed (Figure 2, above), and when oil enabled better transport of crops to market, use of tractors and other farm equipment, and medical advances such as antibiotics. The Green Revolution allowed agricultural production to expand greatly during this period. It used fossil fuels (particularly oil and natural gas) to enable the synthetic fertilizers, irrigation, hybrid seed, herbicides and pesticides, allowing increased food production.

It is likely that increased consumer and business debt following World War II (Figure 4) also played a role in the post-World War II ramp up.

Figure 4. US Debt excluding Federal Debt as Ratio to GDP, based on Z1 Debt data of the Federal Reserve and GDP from the US Bureau of Economic Analysis.

Figure 4. US Debt excluding Federal Debt as Ratio to GDP, based on Z1 Debt data of the Federal Reserve and GDP from the US Bureau of Economic Analysis.

The reason I say that debt likely played a role in this ramp is because at the end of World War II, people were, on average, pretty poor. The United States had recently been through the Depression. Many were soldiers coming back from war, without jobs. Without a ramp up in factory work and related employment, many would be unemployed. A ramp up in debt fixed several problems at once:

  • Allowed low-paid workers funds to buy new products, such as cars, that used oil
  • Allowed entrepreneurs funds to set up factories
  • Allowed pipelines to be built, and other support for ramped up oil extraction
  • Provided jobs for many coming home from the war effort

The debt ramp up, and the resulting increase in oil production, raised living standards. Figure 2 shows that the increase in per capita energy consumption was far greater in the 1950 to 1970 period when oil production was ramped up than in the coal ramp-up between 1840 and 1920. The long coal ramp-up period does not appear to have been accompanied by such a big ramp-up in non-governmental debt.

Tentative Conclusion

A tentative conclusion might be that as long as we can keep ramping up availability of energy products and debt, Malthus’s views are not very relevant.

Of course, things aren’t looking as benign today. World oil production has been close to flat since about 2005 (Figure 5).

Figure 5. World crude oil production (including condensate) based primarily on US Energy Information Administration data, with trend lines fitted by the author.

Figure 5. World crude oil production (including condensate) based primarily on US Energy Information Administration data, with trend lines fitted by the author.

The world has been able to increase production of other fuels to compensate so far. Unfortunately, the big increase is in coal (Figures 1 and 2). This mostly relates to growth in the economies of Asian countries, which are large users of coal.

The cost of oil has more than tripled in the last ten years. The higher cost of oil is a problem, because it leads to recession, unemployment, and governmental debt problems in oil-importing countries. See my posts High-Priced Fuel SyndromeUnderstanding Our Oil-Related Fiscal Cliff, and The Close Tie Between Energy Consumption, Employment, and Recession.

Continued increase in debt now seems to be running into limits. Federal government debt is in the news every day, and non-government debt seems to be contracting relative to GDP, based on Figure 4.

Looking Ahead

I am not sure that we can conclude that we are headed for catastrophe the day after tomorrow, but the graphs give a person reason to pause to think about the situation.

The reason I write posts is to try to pull together the big picture. If we only look at the latest new item  forecasting huge increases in tight oil production or talking about 200 years of natural gas, it is easy to reach the conclusion that all of our problems are past. If we look at the big picture, they clearly are not.

Debt problems are closely related to high oil prices in recent years. Debt problems are today’s issue, and they are not being considered in the huge oil and gas forecasts we see everywhere. The new tight oil and the new shale gas resources likely will need to be financed by increasing amounts of debt, so there is a direct connection with debt. There is also an indirect connection, through governmental debt problems, higher taxes, and the likely resulting recession (leading to lower oil prices, perhaps too low to sustain the high cost of extraction).

Also, it is interesting that the supposedly huge increases in US oil supply don’t really translate to any discernible bump in world oil supply in Figure 5.

We know that the world is finite, and that in some way, at some point in the future, easily extractable supplies of many types of resources will run short. We also know that pollution (at least the way humans define pollution) can be expected to become an increasing problem, as an increasing number of humans inhabit the earth, and as we pull increasingly “dilute” resources from the ground.

Based on earth’s long-term history, and on the experience of other finite systems, it is clear that at some point, perhaps hundreds or thousands of years from now, the earth will cycle to a new state–a new climate with different dominant species.  It may turn out that these new species are plants, rather than animals. The new dominant species will likely be ones that can benefit from our waste. Humans would of course like to push this possibility back as long as we can.

At this point, my goal is to pull together a view of the big picture, in a way that other analysts usually miss. The picture may not be pretty, but we at least need to understand what the issues are. Is the shift in the cycle very close at hand? If so, what should our response be?

160 thoughts on “Why Malthus Got His Forecast Wrong

  1. I find it troubling that some of the more scholarly comments here suggest that population levels are stabilizing or decreasing. This assertion is not borne out by any research that I’m familiar with. For starters, anyone making claims about population growth should understand the term:


    ” A positive growth ratio (or rate) indicates that the population is increasing ” i.e. this means anything over 0.0 states that the population is growing.

    I really don’t care about theories regarding fertility rates, women’s education, immigration, etc. All that counts is the fact that global population is increasing as well as the population of the US. Please don’t argue with me – direct your complaints to https://www.cia.gov/library/publications/the-world-factbook/fields/2002.html

    US growth rate = 0.9% (this is over 0.0 and the math over time shows the problem)
    World = 1.096%

    Maybe a little simple math is in order: http://www.youtube.com/watch?v=hM1x4RljmnE

    Perhaps subscribing to the right organizations would help: http://www.populationconnection.org/site/PageServer

    Or, maybe look at the UN predictions: http://esa.un.org/wpp/other-information/faq.htm#q1 (10B in 2083)

    Perhaps reading something by a guy who has studied this all his adult life: http://www.amazon.com/The-Dominant-Animal-Evolution-Environment/dp/1597260975/ref=sr_1_1?ie=UTF8&qid=1355716646&sr=8-1&keywords=dominant+animal

    Then we have the totally insane idea that finding new sources of energy justifies having more humans on the planet. Ultimately, humans need more than energy supplies to have a decent existence. Apparently, we are too delusional to understand what the current high rate of other species extinction means to us; or the soil problem; or desertification; or ocean acidification; etc. All this before we even bother to mention GW. Our collective delusions seem to have convinced us that the role of planet earth is to provide for the absolute maximum number of humans.

    I believe that a species that is capable of putting robots on Mars, can understand the simple math of “overshoot”. Also, large groups of people have done extraordinary things in the past when confronted with impending catastrophe. Clearly, in our current predicament, the central problem for human survival is our reproductive behavior; clearly we should have a goal of cutting our current population level in half over the next century by the most humane means possible; clearly, the solution is to only have one child per group of people (not one child per woman) – do the math. And yet, this line of thought is inconceivable in our current public discourse. Obviously, there are reasons why we can’t allow ourselves to think in this fashion.

    • You have no doubt seen my graph:

      World population by area

      The people who look at birth rates forget immigration. There are very few places that are net negative on population–mostly areas of the Former Soviet Union and Japan. If I remember correctly, Italy as well, because of tight immigration laws.

      We are not making much progress, because much of the world population is so young. Even if they have only 2.1 children per woman, the world’s population will continue to rise.

      • I think you are right. And also, people tend to forget that just stopping immigration is not an automatic fix for a growing population. The US has lots of immigrants performing tasks that we seem to want performed. It is not clear that removing the immigrants will lead to population stabilization or decrease. Perhaps we will breed our own workers for those tasks – who knows? Very hard to predict what indirect factors will change population growth patterns without actually addressing the problem itself.

  2. Gail, if you have not seen Hayao Miyazaki’s ‘Nausicaä of the Valley of the Wind’, you might really enjoy it, as it depicts a future world where plants, fungi and insects are the dominant species, feeding on pollutants created by humans. You might appreciate a reference to a nice research paper a bit more than an anime film, but i think art can expand our minds a bit and perhaps help us prepare for the strange twists and turns the future may take.
    Thank you for this nice post, by the way. Every year i think that this just can’t go on, and it does, and i feel a bit Malthian. Anylysing where he went a little amiss is a good exercise.

  3. Pingback: Véspera de nada » Blog Archive » O erro de Malthus

  4. Here is a little more information on soil minerals which serve as plant nutrients, organic matter in the soil, weathering, losses to leaching, etc. I will give you a few excerpts from Toby Hemenway’s book Gaia’s Garden. If you go to Amazon, you can use the ‘look inside’ feature and search for ‘Bringing the Soil to Life’. They will let you look at about 4 pages, which isn’t the whole story, but will give you a good flavor for what is going on.

    ‘Once these nutrients have been chiseled out of the stone, in a natural ecosystem they are husbanded with great care. Life is the great recycler, scrupulous in not letting go of any useful substance. An example from a typical northern forest illustrates this. Researchers found that the plants and soil of 1 hectare of forest contained 365 kilograms of calcium. Of this, only about 8 kilograms (2 percent) was lost each year in runoff. Most of the forest’s calcium–98 percent–was being decomposed and held by soil life and transferred back to plant roots for another round. The washed-away 8 kilograms of calcium could easily be acquired by the forest each year: More than half that much splashed down as dissolved calcium in rainwater. The remainder of the lost calcium could be weathered from the rocks by roots and soil life.’

    ‘How does life do such an incredible job of recycling, and how can we duplicate this economy in our gardens? To work toward an answer, let’s look at the fate of a falling leaf as it composts into nutrients and is readied for a return to life.’

    And then if you follow along on the next half dozen pages, you will learn exactly how Mother Nature accomplishes the feat, how The Green Revolution destroys the ability of Mother Nature to do her work, how the agriculture practiced before the Green Revolution destroyed the ability of Mother Nature to do her work, and what we need to be doing instead.

    I warn you that I am not a farm consultant for soils. But my guess is that if you are starting with seriously degraded soils with mineral imbalances, you may very well need to make mineral amendments to your soil. If years of abuse have depleted the calcium, you may have to purchase calcium and add it. If you have the good fortune to inherit a healthy piece of soil, then you can just go into maintenance mode and you won’t have to buy much of anything if you recycle everything.

    It is also quite possible that extreme environments such as the wet side of the Cascades, which get an awful lot of rain in the winter when soil life is mostly dormant, may be particularly prone to the leaching of nutrients. It may be that these environments are simply not suitable for growing annual crops. Steve Solomon, who lived there, claims that if you dig down below the forest duff, you quickly run into nutrient depleted soils.

    Don Stewart

  5. Dear Gail, Even though I commented earlier I still like reading your post. You have many.many responses and have actually either felt the public pulse or hit a nerve. I’m not sure if poeple realize that you’re not claiming to be an expert. You just reporting your facts and observations as you personally crest the horizon. It’s obvious that you are leaning things from your readers and that is very good.

    So here’s what i think again. If you keep stirring the pot…….i’ll keep adding the salt and pepper. Keep Blogging. Keep Writing.

  6. Dear Gail
    My interpretation of your experiences in Russia is pretty grim: a country that collapsed and is still getting worse. Then I read Dmitry Orlovs report from St. Petersburg today and it is all sweetness and light. Ugo Bardi chimes in and agrees that everything is getting better over there. Since I have no desire to spend a year touring around Russia trying to decide for myself, I can’t come to any conclusion.

    I have similarly been looking into the interesting questions that you, in part, raised about soil fertility and the end of fossil fuels, and the need for mined minerals. I find diametrically opposite conclusions. Some people find, with evidence, that just adding organic matter to the soil is all that is needed. Others find, with evidence, that the addition of very specific mined minerals is essential to restore nutritional balance.

    In short, I am just not smart enough to sort out all the conflicting evidence. Do you have any suggestions? Am I just too stupid to figure it out?

    Thanks…Don Stewart

    • I don’t think you are stupid. I think we live in a world similar to that in which people each described an elephant very differently, depending on which part of the elephant they were looking at (legs, trunk, tail, side). The reports we get are all skewed by the perspective of the authors. Somehow, we have to keep trying to dig through, and see what the big picture is saying.

      These are my takes on the two questions you mentioned:

      I think in Russia, there is a big difference between the major cities (St. Petersburg and Moscow) and the rest of Russia. I know Dmitry makes this distinction as well. There is also a distinction between things that can be helped by private investment (more cars, more restaurants, etc) and things that require government upgrades (roads, pipelines, etc.) The private investment part is doing well. The public part is doing less well. There are many indicators that things are not going all that well. In 2010, the life expectancy for males was only 63.0 years. This is far lower than for other developed countries. You need to somehow wade through different trends. The country is terribly dependent on oil and gas exports for tax revenue. A report by Mark Lewis of Deutsche Bank indicated that Russia needs a price of $115.90 to meet its budget (Slide 26 of this presentation).

      With soil, I think that there are long term and short term issues. The way nature has arranged things, base rock erodes at a rate of about 1″ per 1,000 years. It provides the micronutrients we need, and is the major source of new top soil. As far as I can see, the only truly long-term sustainable course of action is the one nature provides. Nature also has a system of predators, insects and microbes. For now, humans have taken over the role of top predator. I don’t think the current system, with humans as top predator, can last. Eventually, the natural system will cycle to a new equilibrium, with new top species–not humans.

      The sustainability actions are about providing fixes, nearly always temporary (in geologic time) and not quite complete, for our long-term problems. If we define success in terms of 50 years, or 100 years, or even 500 years, some of them may well be successful. It probably doesn’t hurt to find out.

      The sustainability fixes nearly always have a fossil fuel component to them, so that “embedded energy” is part of the solution. This works for now, but we can’t count on replicating them for the long term. For example, forest gardens assume that we have a fossil fuel system that allows us to find plants from other areas, and move them to the desired location. We have educated people who can study the related needs of plants, and try to figure out which plants are complementary. Over time (perhaps very long–say 500 years, but it could be shorter), nature is almost certain to undo our work, through changing climate, or mutations of plants, or diseases, or something. The result is likely to be a somewhat changed system that produces somewhat less food for humans (“reversion to the mean”). Without education, and access to plants at a distance that we might substitute for ones that are going downhill, it will be difficult to keep up the system for the long term.

      Nature has provided its own system which works very well, although it doesn’t produce as much human food as we would like. We can try to imitate it, and can come up with a mix of plants that provides a greater mix of food and no degradation of the soil. It is hard to do as good a job as nature, though, and it will be very difficult to maintain for the long-term. Also, the share of the food that humans get from these gardens is likely to be skewed in current analyses with what we are capable of now, when we have tools such as ladders and shovels and ways of shielding plants from predators. If we lose these, we will go back to a situation closer to hunter-gatherers.

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