Population Sustainability.

There comes a time in every bloggers life when the people who comment on topics provide the inspiration for future posts. For me this day has come from an interesting tangent brought about by one my more recent posts on Australia’s property market. The underlying ideal behind a lot of property investors is that people will always need a place to live and that we’re always going to have more and more people in the world so it becomes a very secure investment. This then begs the question, how long can continued population growth continue before we can’t sustain it?

What we should first look at is the historic population trend for us humans:


It’s an interesting graph mathematically as it combines several different behaviours. The first is for all intents and purposes a steady state function. All the way up to approximately 1000BC the human population did not undergo much growth at all and for the most part was steady. Around 1000BC to 900AD we can see a typical steady, linear growth function where the population increases basically at a set rate every year. After 1000AD it starts to get really interesting and demonstrates an exponential growth function that rockets up unimaginably high. Generating a line of best fit for this data (mathematical note: I’m using data from 0 to 2000 so the equation is simpler) gives something along the lines of y = 110.53e0.1048x where y is the population, x is the year and e is the mathematical constant. Using this to map future populations is a tad scary, take a look in the Wolfram Alpha for a taste.

The graph shows what happens when technology significantly improves life and thus allows people to live longer and have more children. Things like the invention of agriculture, the industrial revolution and the baby boom following world war 2 represent those significant changes in the population. It’s also interesting to note that they also correlate succintly with the change in mathematical behaviour of the graph from constant to linear to exponential. As anyone with a scientific bent will tell you exponential growth can’t last and will eventually end once a limitation in resources is reached.

Now before I go into a bit of philosophical hand waving about the world’s population I want to get a definition clear that is wildly misrepresented. Third world countries refers to a political affiliation, not a level of development. The term is used today to describe countries that are more aptly described as developing nations and is often used as a call to sympathy for them.

The world as it stands today could easily support the current population with a decent standard of living. Predominately the issue seems to stem from our inability to provide life’s essentials to certain countries, namely those ones who are still developing.  There will come a time when even the western world won’t be able to provide enough food for its people and this is when the populations will have to plateau. Current thinking is this will happen sometime around 2050 with the world’s population hitting a staggering 9 billion. However this idea is rooted in today’s ideals and technology and as we’ve seen in the past revolutions in technology enabled the human race to expand at rates that no one thought was possible before. A classic example of this was the horse manure crisis of 1984, where planning authorities predicted that all the streets of London would be buried in 9 feet of manure. Of course this did not happen thanks to a technological breakthrough and the potential is there for this to happen with us humans.

My personal view on the matter is that whilst exponential growth is unsustainable the human race as a whole has a lot of potential to overcome these issues. Unfortunately history has shown that until the problem becomes critical not much will be done to avoid it, as we’ve seen with things like alternatives to fossil fuels. The good news is that a lot of the framework is already in place and proven to be able to cope with a much larger population, we will just have to encourage our governments to bolster sustainable practices and put pressure on other governments who don’t.

I’ve tried to steer clear of squarely blaming political issues as the cause of all the problems that third world countries face as it is only my opinion and I haven’t been able to find substantial evidence to back it up. So instead I want to put it to you my readers: what are the causes of the issues that developing nations face? Is it their tyrannical governments? Or does it stem from inherit environmental problems?

We as a species are quite capable of sustaining our current population with a good standard of living. What is stopping us from accomplishing this?

Update: Slight rephrasing of the question. As my intrepid fellow blogger Andrew Carr points out this issue isn’t as simple as I might have first thought.


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  1. I don’t think you can attribute any single cause behind all developing countries (As Modernization Theory tries in highlighting their lack of Capitalism, and Dependency Theory/World Systems Theory in outlining the exploitation of the developing by the developed). Each country has unique circumstances that affect why it is in trouble.

    Take Argentina, in the 2nd half of the 20th century it was common to compare Argentina and Australia. Today no one would do so. Argentina even had greater natural resources like oil, but when it set about privatising & liberalising in the 1990’s it caused major economic collapse, whilst Australia boomed.  You could attribute this to military, political, environmental, regional factors, even the individual competence of the leadership, and yet Argentina is actually a pretty stable, middle ranked country, but the difference between it and Australia today, having been seen as very similar only a few decades ago shows the difficulty.
    Or take Africa. Some parts have been destroyed by the colonizers of the 19th century, others by modern dictators and demagogues, others ravaged by AIDs or flow on effects (such as huge refugee populations from badly managed neighbours).
    Can I recommend Gapminder: http://graphs.gapminder.org/world/ It lets you look at all countries, colour coded by region, graphed over time and by any factors you would like (ie GDP, morality rates, fertility, environment, labour, health etc). It shows the critical importance of regional factors  but also those countries that escape that orbit and how they did it.
    Development is a massive massive area, best tackled country by country, rather than worldwide. But the best criteria we have is  if you want development so as to restrain population: Economic & Political Stability = less kids. We just don’t know how to provide the first (straight aid doesn’t work, capitalism and socialism have cultural contingiencies), and as outsiders we can’t impose the latter.
    I can provide you some good readings on this if you’re interested, but it’s far too simplistic to try and put it all down to one common issue such as bad governance or environmental degredation.

  2. I think I’m going to lose hours in Gapminder, thanks for the link.

    It seems the issue facing developing countries can’t be pinned down to a single source, and the causes are different for each individual case. That would explain why the advances that have helped the first and second world countries haven’t had the same impact elsewhere, they didn’t solve the issues that they were facing.

    I don’t think we need to restrain population growth per say, more that we have the ability to support the current population easily it’s just that for some reason we don’t. This was why I tended towards political issues as the capability is there, for instance we’re able to grow more than enough food to feed everyone in the world, yet large populations still starve. It’s quite possible that the region they’re living in is not capable of sustaining a population of the size they have, and that would shift the focus from the rulers to the subjects.

    You’re right, this is quite a complicated issue.

  3. You say that we don’t need to restrain population growth because we are able to support the current population, but what about the population of tomorrow? We need to be setting limits based on what is sustainable, and not ignoring or dismissing the issue.
    It’s true that technology has made huge advancements in the field of efficiency, the problem is that increases in efficiency rarely lead to lower resource consumption. Paradoxically, we end up increasing our consumption of the resource as it becomes cheaper.
    Technology will continue to play a very important part in reducing our impact on the earth, but unless we have the government policies to stop us using more and more, it can in some cases make the problem worse.
    Argentina has gone from being the 10th richest nation in the world with a population of 4 Million in 1900, to today being the 49th richest and having a population of 40.6 Million. Check out this gapminder (skip to 1900). It’s hard to take that out of the equation and blame it on privatisation and liberalisation alone.

  4. I guess my viewpoint on the matter wasn’t clear enough but I do believe the current rate of growth is unsustainable. However there is a natural limit that we’ll eventually hit, and that was going to be my point of where it plateaus. However this is probably the worst way to go about it, since that means we’re at capacity in terms of world population and that would put all of the world’s resources at considerable strain.

    The Khazzom-Brookes postulate is an interesting idea as it seems almost counter intuitive to for our desire for unlimited clean energy. Unfortunately I believe it is inevitable that we’ll improve utilization of resources as time has shown when something gets scarce we find better ways of getting it.

    I steered clear of mentioning that this kind of exponential growth was the precursor to us populating other worlds (with the only viable alternative right now being Mars) as that’s a whole other discussion. However more and more it seems that establishing an off world colony would teach us so much about efficient and sustainable living that could then be used here on earth. For me it seems like it might be the only way to ensure the continued survival and prosperity of the human race.

    I’m looking at putting in a better comment system so you’ll be able to edit your own comments so you won’t get caught out by formatting problems 🙂

  5. Chris – Are you suggesting Argentina is poorer because it is more highly populated ? Ie that their is a negative (for the country) correlation between population & GDP ? That is more people = poorer ? (or perhaps in ratio more people than neighbours ?).  If you look at the figures of world population by country (http://en.wikipedia.org/wiki/List_of_countries_by_population) and compare to Countries GDP per capita http://en.wikipedia.org/wiki/List_of_countries_by_GDP_(PPP)_per_capita) it’s pretty clear there is no link (ignore the oil rich tiny states). Even if you use nominal GDP it’s hard to say there is a definate link (http://en.wikipedia.org/wiki/List_of_countries_by_GDP_(nominal)) and if there is, it is a positive link, with the vast populations of China and India leading to their economic rise, and perhaps explaining the USA’s triumph over the UK in the 20th century (though it was far from the largest country during this time, suggesting many other factors at work).

    The concern Chris raises is important, however it is not new. In 1798 Thomas Malthus raised the same idea noting that populations grow exponentially (2x4x16) whilst resources only grow sequentially. However this history proves its doutbtfulness. Over 200 years have passed since Malthus wrote (and the idea was quite common before his time) and yet we still have a clear capacity to feed the worlds population should we so direct our energies.
    Secondly, and my main reason for optimism is that these increase have come entirely from increased efficiency of food stuffs. People still have quite similar diets to that of 500 years ago. Meat, bread/corn/rice, dairy, vegtables. Only the quality and quantity has changed. But as we begin to prosper in bio-engineering of crops that is due to radically change.  Certainly not quickly enough to save the millions starving today, we face a future where food is available from labs in white pre-packaged containers, with nary an animal or piece of dirt in sight. But even if this future is not to be, we have 200 years of straight empirical data to show that we are able to meet the challenge of rising populations should we choose.

    Overpopulation certainly is a problem, but the cause is actually the solution. Whilst early development leads to population increases (think the baby boomers post 1945), further development towards middle class status tends to begin to slow down fertility rates, as socities change their focus from survival to culture and quality of life. And indeed we are seeing this already. The last 30 years have seen over 1 billion people brought out of poverty,  with substantial rises in the conditions for many many more (Particularly in Asia).  As such the fertility rate of women in the developing world have essentially halved from 6 to 3 (which is why we are aiming for 9 billion not 12 or 18 billion by 2040 as a Maulthausian theory would predict.  That’s still too many, but if we keep developing we can bring this problem under control.  How you do that is a question best left for another post, though I’m happy to continue the discussion.

    The real X factor here is that human ingenuity means we unlike all animals or machines are not bound by the numbers. Robots can only make X number of boxes from Y number of resources. But humans can change their valuations, and indeed we already spend much of our time and energy ‘growing’ via resources that take almost nothing from the wider environemnt (IT, Education, Culture, etc). Animals are limited by fixed needs and wants, conscious humans arn’t and so limitless growth is not by definition impossible. If we were better at aiding development we would be better at slowing population growth

  6. The argument should not simply be about GDP or food production, the most important factor in my opinion is our impact on the biosphere, yet this is for the most part totally ignored whenever the topic is brought up.
    It’s true that humans are skilled at generating enough food to meet the demand through increased efficiency and the like, but at what cost? We are becoming increasingly demanding on our natural resources, how can we go on increasing the number of mouths to feed and expect to simultaneously reduce our environmental impact to sustainable levels?
    This head-in-the-sand attitude, relying on non-existent zero impact technologies is reckless and irresponsible. Our economies are based on the false idea that population growth = economic growth = higher standard of living. I don’t believe we need to go on expanding our population to raise the standard of living. As you say, we are an ingenious species, I believe we can have culture and education and technology without ransacking the planet in the process.

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