What's for dinner? (Part 1)

August 25, 2014

I fear we're still doing it wrong. Well, it's kind of obvious that we're doing it wrong, but I think we're trying to get it right in ways that don't seem close to what we need to do to get it right. As a society, we collectively shrug our shoulders at the specter of things like the ecological impacts of climate change. The slow-moving, amorphous nature of which has us treating the issue as if it were equal to a day at the spa, when in truth we're already actively engaged as boiling frogs.

August 19 was this year's Earth Overshoot Day, the day in which the Global Footprint Network estimates that we'd used up the annual replenishable bounty the earth provides for us. With 134 days left in the year, the cupboard which the planet's ecosystems had filled with this year's "crops," was already bare. That means we're going into our ecological savings account for over a third of the year's needs. Increasing demand from the existing population base, paired with a growing population, leads to a compounding of an issue that's already highly problematic. In fact, the original Earth Overshoot Day occurred in early October of 2000. So, in the space of just fourteen years, we've moved this date forward over forty days. I have to wonder how much longer we can press in this direction.

In 1961, humanity used just about three-quarters of the capacity Earth had available for generating food, fiber, timber, fish stock and absorbing greenhouse gases. Most countries had biocapacities larger than their own respective Footprints. By the early 1970s, global economic and demographic growth had increased humanity’s Footprint beyond what the planet could renewably produce. (emphasis minWe went into ecological overshoot. Today, 86 percent of the world population lives in countries that demand more from nature than their own ecosystems can renew. According to Global Footprint Network’s calculations, it would take 1.5 Earths to produce the renewable ecological resources necessary to support humanity’s current Footprint. Moderate population, energy and food projections suggest that humanity would require the biocapacity of three planets well before mid-century. This may be physically unfeasible. (understatement theirs)

Source: UN Report "World Population to 2300"

In 1961, global population was around three billion. It eclipsed seven billion a few years ago and several respected sources estimate it will climb to around nine billion by mid-century. With that in mind, I thought we should take a look at the ideas of Thomas Malthus.

Let's start with a bit of homework. Sal Khan gives a nice overview of the relevant concepts in the lesson below.

For those that skipped the video, The Malthusian Trap is the idea that a population will tend to grow beyond its ability to feed itself. Malthus developed this idea in the midst of the British Agricultural Revolution, an extended period of greatly increased agricultural output.

It is still argued that an English agricultural revolution happened in the century or so after 1750. One obvious reason behind the argument is the fact that an expanding population from this time on was largely fed by home production. In 1750 English population stood at about 5.7 million. It had probably reached this level before, in the Roman period, then around 1300, and again in 1650. But at each of these periods the population ceased to grow, essentially because agriculture could not respond to the pressure of feeding extra people. Contrary to expectation, however, population grew to unprecedented levels after 1750, reaching 16.6 million in 1850, and agricultural output expanded with it.

Source: BBC

Malthus' original postulates included the idea that population grew geometrically (2,4,8,16,32), whereas agricultural production grew arithmetically (2,4,6,8,10). Characterizing agricultural output as being governed by an arithmetic process has proven incorrect. At least, that's the argument against Malthus. Yes, population does grow in a compounding fashion, but what of agriculture? Our food supply has largely kept pace with population growth, but in what way, and at what cost? Further, does an acre of land become more than acre in subsequent years? Changes in techniques and the use of High Yield Variety (HYV) crops have led to massive improvements in yields, but they do not increase the amount of arable land available to us. In fact, by increasing the available food supply in the short run, the amount of high quality farmland decreases as populations expand and cities spill out into their surrounding areas. This forces farms to migrate out onto land which is often less productive, or, worse yet, it can lead to the clearing of forests.

As I mentioned before, Malthus must have understood the changing circumstances he was living in as the British Agricultural Revolution was well under way by the time he wrote his essay on population in 1798, but he believed that the increasing agricultural yields could not go on forever. (The Khan Academy video covered this well.)

The power of population is so superior to the power of the earth to produce subsistence for man, that premature death must in some shape or other visit the human race. The vices of mankind are active and able ministers of depopulation. They are the precursors in the great army of destruction, and often finish the dreadful work themselves. But should they fail in this war of extermination, sickly seasons, epidemics, pestilence, and plague advance in terrific array, and sweep off their thousands and tens of thousands. Should success be still incomplete, gigantic inevitable famine stalks in the rear, and with one mighty blow levels the population with the food of the world.

—Malthus T.R. 1798. An essay on the principle of population. Chapter VII, p61

One of the more interesting pieces to Malthus' theory was the idea of positive and negative checks. The graphs below from the s-cool site are instructive.

  • The first graph shows the presumed trajectories of food supply and population given the aforementioned arithmetic and geometric natures. (Food production has outstripped this expectation. I'll go into that further later in this post.)

  • The second graph visually represents Malthus' idea of positive checks, including famine, disease and war, which "check" population by increasing the death rate. Positive checks kick in periods of overshoot to bring population levels back within levels which the food supply can sustain.

  • The third graph shows the corollary to the second, negative checks, which could curb population by reducing the birth rate via abortion, birth control, prostitution, delayed marriage and celibacy.

In Malthus' model, population would grow unabated to a point where it would hit a wall when it exhausted the . From there, positive and/or negative checks would step in and curb population growth to meet the available food supply.

We could go further into Malthus' work, but I think we've covered the bases we need. For now, I'll close with a tip of my cap to the alarming nature of this work, by way of Malthus' own admission, which closes with the hope that the logic herein is faulty and that sharper minds will be drawn in to point out those flaws. I'll give a hearty hear, hear to that!

The view which he has given of human life has a melancholy hue; but he feels conscious, that he has drawn these dark tints, from a conviction that they are really in the picture; and not from a jaundiced eye or an inherent spleen of disposition. The theory of mind which he has sketched in the two last chapters, accounts to his own understanding in a satisfactory manner, for the existence of most of the evils of life; but whether it will have the same effect upon others, must be left to the judgement of his readers.

If he should succeed in drawing the attention of more able men, to what he conceives to be the principal difficulty in the way to the improvement of society, and should, in consequence, see this difficulty removed, even in theory, he will gladly retract his present opinions and rejoice in a conviction of his error.

-Malthus T.R. 1798. An essay on the principle of population. Preface

In Part 2 I'll jump ahead to the 1960's. From there, I'll discuss our current circumstances before taking a stab at what the future might hold. Stay tuned.