Last week I wrote about population and argued for regarding it as a priority to take measures to see a declining population globally.
This post is a defence of Malthus, an elaboration of what I wrote last week.
To most people I imagine Malthus is an old guy who said we’d all starve and we didn’t so he was wrong and we don’t need to worry. In fact almost everything that Thomas Malthus (1766-1834) wrote about productivity and population was correct. He was the first writer to describe a crucial ecological law, that in an ecosystem any species will multiply until the limits of its resources are met and then either stay at that population level, or decline in population. It was this insight that allowed Darwin to add another element to his concept of natural selection.
In discussing this concept in relation to human society Malthus of course recognised that humans can transform ecosystems in the way that most species cannot. He didn’t believe that agricultural was static, in fact he wrote in full knowledge of the enormous increases in productivity that had occurred in the C18 in Britain. He recognised that in order for agriculture to be more productive, either more land needed to be brought into cultivation or the existing land had to have more inputs added to it. These inputs could be in form of new techniques like crop rotation, or in the form of more labour, better cultivation (ie deeper ploughing), or better fertilising &c &c
Malthus feared, however, that in the long run increases in productivity would not keep pace with the growth in population. As this was in the days before contraception, Malthus’s only two solutions were emigration to new lands, and encouraging people to marry at a later stage in life and have fewer children.
What has happened for the two centuries since Malthus made his argument is that the extensive use of fossil fuels, first coal, then oil, made his arguments seem irrelevant. Almost all the cultivatable area of the earth was put under cultivation, and fossil fuels enabled the use of machinery and artificial fertiliser inputs. Productivity increase manyfold. However, note that during this period the population also increased manyfold: in the later C20 population growth was more than exponential. Nor was poverty solved.
And in many parts of the world during this period Malthusian remedies occurred anyway, for example many millions of Europeans emigrated to the United States and Canada in the C19, and the average number of children per couple, in Britain at any rate, dropped towards the end of the C19 from previously higher levels.
However with the approaching problems of peak soil and peak oil (discussed in previous posts), we are back in Malthusian territory. If we look at his remedies we find that there is no more land that can be brought into cultivation, and further intensification of cultivation is no longer possible because oil is running out. There is no alternative source of energy that has the same chemical properties as fossil fuels, especially oil, or the same energy yield (the amount of energy remaining once the energy required to generate it is subtracted). Alternative energy sources such as wind and wave-powered generation have more modest yields, and so too, despite the arguments of its proponents, does nuclear.
There is no obvious source of the massive amounts of power required to keep on with the process of intensification, and in any case, intensification will soon run up against the physical limits of a finite world, for example, despite all possible inputs and technological innovations, beyond a certain point it is simply not possible to produce any more protein from a given area of cultivated land.
Further inputs of energy also run into the problem of pollution. It has been recognised that beyond the problem of increasing production using up resources (in an example from last week, the fact that groundwater worldwide is becoming depleted), greater activity means more pollution (so the groundwater that remains is increasingly likely to be polluted). With fossil fuels the pollution issue was first noted as obvious air pollution in industrial areas (including smog) in the C19. As this pollution was mitigated then Sulphur dioxide and other pollutants were recognised as causing acid rain and acidification of lakes hundreds of miles away from industrial areas. As measures were put in place to mitigate these problems the global increase in atmospheric Carbon dioxide was identified as a problem, and we are still stuck on remedies for this. At each stage, dealing with the pollution becomes more difficult and more costly. Further grand schemes, for example capturing solar energy in vast solar arrays in space and beaming it as microwave radiation to the Earth’s surface, would run into the problem of waste heat directly heating the biosphere.
One paraphrase of the laws of thermodynamics is ‘there’s no such thing as a free lunch’. This is not quite true because humans have arguably had half a free lunch, the discovery of fossil fuels. This is only half a free lunch because although during the fossil fuel era just ending humanity went through an amazing period of technological advance, it also did some very dumb things like getting rid of a lot of the biodiversity of the planet, and running the life-support systems of the planet into the ground, to say nothing of starting a dangerous period of global warming.
To return to Malthusian remedies to the problem of population outstripping production: emigration is also no longer an option. Many people in less developed countries would dearly like to emigrate to developed countries, but these societies are by and large unwilling to accept them. In any case, even if large numbers of people from the developing world were allowed to settle in the developed world, this wouldn’t solve any global problems, it would simply mean that unsustainable consumer demand would accelerate.
It seems that having fewer children is the only option for facing these problems (for everyone) and that, despite the scorn of all ‘right-thinking people’, Malthus was correct after all.
Next week: further thoughts on population, and what Australia could do about the population question