The world population recently topped 7 billion, and current UN predictions are that it will reach 9 billion by 2050, but does this matter – are we facing a crisis of overpopulation in which population growth will outstrip the limits of the planet to provide for us?
The original and most famous exposition of this thesis was by Thomas Malthus in 1798 whose basic idea was that population increased exponentially but food supply only increased incrementaly, so population growth would always outstrip the ability of the population to feed itself. Malthus predicted that the world would run out of food by 1890.
Malthus of course failed to foresee the incredible increases in agricultural yields that were to be brought about by the green revolution after ww2 (nicely summarised in the video below) which trebled food production per acre in countries such as Mexico and India – allowing them to sustain increased population
However, such population increase lead Malthusianism to be revisited by Paul Erlich in his 1968 population bomb, who predicted that high birth rates would lead to mass famine and reduce the population by at least 1/5th by the end of the 1970s.
Again with hindsite Erlich also got it wrong, and clearly not because of any global reduction in population, which has grown significantly since Erlich’s day, so could it be that the Malthusian doomsayers are just wrong?
Criticisms of Malthusianism – Overpopulation is a myth (.com)
This web site offers (at time of writing) six video-based criticisms of the Malthusian view point – Some of these include
- Going back to the graph at the top of this post, the average projection has it that the world population will peak at 9 billion in about 40 years from now and then start to go back down, although the overpopulation web site draws on even more optimistic figures of an 8 billion peak in 30 years.
- Many developed countries, most noteably Japan, have very low fertility rates, far below the level necessary to replace the population. These countries face an increasing depenendency ratio as the number of people retiring relative to those of working age increases.
- Overpopulation proponents suggest that there is not enough food for everyone, however, the FAO and WFP point out that there is enough food for everyone, but several hundreds of millions of people lack access to that food because of such things as poverty, conflict and poor agricultural infrastructure – In other words it’s not too many people that’s the problem, it’s the economic and political systems that block access to available food.
There are more criticisms of Malthusianism on the web site, with data and links!
Limits to growth – How many people can the earth support?
This video, hosted by David Attenborough, lies somewhere between Malthusianism and the ‘overpopulation myth busters’ – It starts off with the point that we are approaching the Earth’s limits to growth, while holding open the possibility that we can prevent meltdown, but only if we make a concerted global effort…..
Some of the evidence being cited for us reaching the Limits to Growth include…
- Nasa’s satellite imagery showing us that we are already using nearly all of the earth’s surface to provide for our needs
- The fact that we appear to have reached the technological limits for increasing food yields per acre
- Extensive land grabs (mostly in Africa) suggest that developed countries are concerned about their ability to feed their populations in the future
- The reduction in capacity many of the earth’s water sources
Attenborough suggests three solutions to our reaching the limits to growth
Firstly we can rely on technological advances to produce more with less land
Secondly we could reduce our consumption
Thirdly we can control population growth in the developing world
None of these are necessarily going to happen of course, and I think I might deal with these in a seperate post…