Keeping Track of World Population

The Malthusian Dillema: Where Do We Stand?

As most anyone knows, human population levels are a key concern when it comes to the sustainability of industrial society. The reason is simple. There are a finite amount of resources on the Earth. Each person, depending upon their level of consumption, must make use of a certain portion of those resources to survive. Therefore, the more people there are, the less there is for each person. At some point, we must also reach the maximum population supportable given the available resources and technology.

At present, the world population of over 6 billion people is already straining the biosphere’s capacity to sustain it. The most immediate limiting factor, of course, is the availability of food.

In fact, the relationship between human population growth and food production was first examined scientifically by Thomas Malthus in his book, “An Essay on the Principle of Population,” published 1798. What Malthus pointed out at the time was that human population had the potential to increase at an “exponential” rate, while food production could only be expected to increase at a “linear” rate. When graphed, a linear increase appears as a straight line at a 45 degree angle, while an exponential increase appears as a curve which quickly shoots to the top of the graph, and then off the chart.

In plain English, the implication is that at some point, human population will increase to the point where it exceeds what can be sustained by global food production. At that point, starvation will provide a limit to further population growth.

Malthus originally predicted that we would already have reached this crisis point, which is known as “the Malthusian Dilemma.” This is because he predicted that population would double faster than it actually has over the past 300 years (Bodley 2001).

Only modern agricultural technologies, combined with the expansion of industrial agriculture around the world have kept us from reaching that crisis point to date. As Lester Brown (1998) suggests, however, we may be running out of time. There are a number of indications that this may be the case:

1. Despite the expansion of more productive industrial agricultural techniques, both area under cultivation and the amount of irrigation water per capita have already begun to decline on a global basis. This suggests that we are already reaching the limits of food production.

2. Most of the available technologies for maintaining, and further intensifying food production are dependent upon fossil fuels, and are therefore unsustainable. This includes not only the fact that agricultural machinery is almost universally powered by diesel, but also the fact that artificial fertilizers and many pesticides are derived from the petrochemical industry.

3. Up until 1997, the world had 3 reserves which could be called upon in the event of a poor harvest, but all three are now nearing their limits. These included:

a. Idled or unused cropland: but most arable land is now in production, and losses to urbanization (or urban sprawl building over farm land) and to land degradation (especially from soil erosion and salinization) mean that available cropland is now in decline.

b. Surplus stocks of grain: in 1996, carryover stocks dropped to their lowest level on record, enough to feed the world for only 52 days, while a 70 day surplus is thought to be needed to provide for global food security.

c. This leaves the one third of the annual harvest currently fed to livestock in order to produce meat. This could be used to feed larger numbers of people because meat production is a relatively inefficient way of producing calories for human consumption compared to consuming grain directly. This is because only about 10 percent of the grain calories are actually converted to usable protein (or meat) calories. This implies that eating the grain directly could support a larger human population than meat.

As Robbins (2005) suggests, however, the world’s poor are already experiencing problems with protein deficiency. In other words, they already don’t have enough meat or other high quality protein in their diet. So eating more grain directly and producing less meat would only make this problem worse. Yes, it would allow more people to be fed, but it would not allow them to be /well/ fed. This again indicates that we are nearing the limits of the population which can be sustained given our available food production technologies.

If that is the case, you might ask, where do we stand in terms of population growth?

Recent articles by Jennifer Mitchell (1998) and Robert Kates (2000) suggest that there is both bad news and good news on the population growth front. The bad news is that the human population continues to grow, despite the fact that we are approaching the limits to food production.

There are three principle reasons for this: (1) the desire for large families, or families of more than two children (the replacement rate), which will cause about 20 percent of the growth, (2) unmet demand for family planning, which will cause about a third of the growth and,
(3) “population momentum,” which will cause about half of the additional growth.

As you will note, the continued desire for large families is actually the least of our worries. This is primarily due to education concerning the problem on the part of international agencies over the past several decades. Both increasing the status of women, and providing educational and employment opportunities for women also help here. This is because women with employment and educational opportunities tend to delay marriage and child birth, and to have smaller families on average.

The next factor, unmet demand for family planning, implies that cheap and affordable means of contraception are often not available, especially to the rural poor. Alternately, the cheapest and most effective means of contraception (such as condoms) may be illegal in some jurisdictions for religious or cultural reasons. This implies that the only effective means of birth control available in many areas is /sterilization/.

The problem with sterilization is that it is permanent. It effectively brings a couple’s reproductive potential to an end. This is problematic because it encourages people to have their children young, and to have large families. This is especially true where children are a couple’s old age security (as in poor countries lacking social programs), and in situations where a couple can assume that one or more of their children will die before they do (as in countries lacking adequate health care).

This problem is best dealt with by providing alternatives to sterilization, and especially by making available affordable, and /continuously available/ methods of contraception.

The bulk of future population growth, however, will be caused by “population momentum.” Paradoxically, this is actually a good thing.

What population momentum means is that due to past population growth, the number of people entering their reproductive years in the present generation is larger than in the previous generation. Because of the previous “baby boom”, even if couples have only two children, total population will still increase because there are more couples having children in the present generation than in the last.

Why is that good news? Because the biggest part of the problem is now being caused by /past/ population growth, not by conditions in the present. As Bodley (2001) points out, therefore, while /absolute/ population can be expected to increase for some time, the population /growth rate/, or the percentage the population grows annually, is already in decline.

That said, continued population growth, and the increased levels of consumption, ecological destruction and degradation which accompany it, remains one of the central issues facing humanity. So does the Malthusian dilemma. For not only is arable land disappearing, so are fossil fuels and water for irrigation, all of which are necessary to sustain current levels of food production. Yet population continues to grow.

So when it comes to human population, the day when Nature raises her hand, and simply says “no more,” may be fast approaching.

References cited, additional readings:

John Bodley (2001) Anthropology and Contemporary Human Problems, Mayfield Publishing Company.

Lester Brown(1998) “Food Scarcity: An Environment Wakeup Call,” The Futurist, January/February.

Robert W. Kates (2000) “Population and Consumption: What We Know, What We Need to Know,” Environment, April.

Jennifer Mitchell (1998) “Before the Next Doubling,” World Watch, January/February.

Richard H. Robbins (2005) Global Problems and the Culture of Capitalism, Pearson Education Inc.