Image: Matt Collins
In 1798 Thomas Robert Malthus famously predicted that short-term gains in living standards would inevitably be undermined as human population growth outstripped food production, and thereby drive living standards back toward subsistence. We were, he argued, condemned by the tendency of population to grow geometrically while food production would increase only arithmetically.
For 200 years, economists have contended that Malthus overlooked technological advancement, which would allow human beings to keep ahead of the population curve. The argument is that food production can indeed grow geometrically because production depends not only on land but also on know-how. With advances in seed breeding, soil nutrient replenishment (such as chemical fertilizers), irrigation, mechanization and more, the food supply can stay well ahead of the population curve. More generally, advances in technology in all its aspects—agriculture, energy, water use, manufacturing, disease control, information management, transport, communications—can keep production rising ahead of population.
Another factor undermining Malthus’s argument, it would seem, is the demographic transition, according to which societies move from conditions of high fertility rates roughly offset by high mortality rates to conditions of low fertility rates together with low mortality rates. Malthus did not reckon with the advance of public health, family planning, and modern contraception, which together with urbanization and other trends, would result in a dramatic decline in fertility rates to low levels, even below the “replacement rate” of 2.1 children per household. Perhaps the human population would avoid the tendency towards geometric growth altogether.
These critiques of Malthusian pessimism have long seemed irresistible. Indeed, when I trained in economics, Malthusian reasoning was a target of mockery, held up by my professors as an example of a naïve forecast gone wildly wrong. After all, since Malthus’s time, incomes per person averaged around the world have increased at least an order of magnitude according to economic historians, despite a population increase from around 800 million in 1798 to 6.7 billion today. Some economists have gone so far as to argue that high and rising populations have been a major cause of increased living standards, rather than an impediment. In that interpretation, the eightfold increase in population since 1798 has also raised the number of geniuses in similar proportion, and it is genius above all that propels global human advance. A large human population, so it is argued, is just what is needed to propel progress.
Yet the Malthusian specter is not truly banished—indeed far from it. Our increase in know-how has not only been about getting more outputs for the same inputs, but also about our ability to mine the Earth for more inputs. The first Industrial Revolution began with the use of fossil fuel, specifically coal, through Watt’s steam engine. Humanity harnessed geological deposits of ancient solar energy, stored as coal, oil, and gas, to do our modern bidding. We learned to dig deeper for minerals, fish the oceans with larger nets, divert rivers with greater dams and canals, appropriate more habitats of other species and cut down forests with more powerful land-clearing equipment. In countless ways, we have not gotten more for less but rather more for more, as we’ve converted rich stores of natural capital into high flows of current consumption. Much of what we call “income,” in the true sense of adding value from economic activity, is actually depletion instead, or the running down of natural capital.
And although family planning and contraception have indeed secured a low fertility rate in most parts of the world, the overall fertility rate remains at 2.6, far above replacement. Sub-Saharan Africa, the poorest region of the world, still has a total fertility rate of 5.1 children per woman, and the global population continues to rise by about 79 million per year, with much of the increase in the world’s poorest places. According to the medium-fertility forecast of the United Nations Population Division we are on course for 9.2 billion people by mid-century.
If we indeed run out of inexpensive oil and fall short of food, deplete our fossil groundwater and destroy remaining rainforests, and gut the oceans and fill the atmosphere with greenhouse gases that tip the earth’s climate into a runaway hothouse with rising ocean levels, we might yet confirm the Malthusian curse. Yet none of this is inevitable The idea that improved know-how and voluntary fertility reduction can sustain a high, indeed rising, level of incomes for the world remains correct, but only if future technology enables us to economize on natural capital rather than finding ever more clever ways to deplete it more cheaply and rapidly.
In the coming decades we will have to convert to solar power and safe nuclear power, both of which offer essentially unbounded energy supplies (compared with current energy use) if harnessed properly and with improved technologies and social controls. Know-how will have to be applied to long-mileage automobiles, water-efficient farming, and green buildings that cut down sharply on energy use. We will need to re-think modern diets and urban design to achieve healthier lifestyles that also cut down on energy-intensive consumption patterns. And we will have to help Africa and other regions to speed the demographic transition to replacement fertility levels, in order to stabilize the global population at around 8 billion.
There is nothing in such a sustainable scenario that violates the Earth’s resource constraints or energy availability. Yet we are definitely not yet on such a sustainable trajectory, and our current market signals do not lead us to such a path. We will need new policies to push markets in a sustainable manner (for example, taxes on carbon to reduce greenhouse gas emissions) and to promote technological advances in resource saving rather than resource mining. We will need a new politics to recognize the importance of a sustainable growth strategy and global cooperation to achieve it.
Have we beaten Malthus? After two centuries, we still do not really know.
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22 Comments
Add CommentAnd we will have to help Africa and other regions to speed the demographic transition to replacement fertility levels, in order to stabilize the global population at around 8 billion.
Reply | Report Abuse | Link to thisThat is certainly a laudable objective but near term, surely we can help the African Continent, by finally jettisoning the IMF World Bank Agricultural model which has failed so miserably. You will note the extraordinary success story that is little Malawi, where the Country converted itself from a country in perennial food deficit into one where it is in surplus. Where, Farmers, are for the most part, living in a hand to mouth type of existence, it surely makes compelling sense to subsidise or finance their inputs [thereby, enhancing yields] upfront and then retrieve the cost at the point of sale. It seems to me that Africa represents an enormous opportunity to apply smart policies for ,aterial gain, given the low base effect.
Re Your wider point. It would be interesting to know how much Agricultural land has been cannibalised by breakneck urbanisation and industrialisation, over the last 100, 50. 10 and 5 years. I suspect its very material. It also seems that the global weather patterns have become much more stressed and this is keeping a cap and even downwards bias re net Agricultural world output. And then I think the average calorific intake per human has increased quite exponentially.
All these things combine to make me conside that the Commodity super cycle is tipping from Metals, Crude and the like towards Soft Commodities.
Aly-Khan Satchu
www.rich.co.ke
"In countless ways, we have not gotten more for less but rather more for more, as weve converted rich stores of natural capital into high flows of current consumption. Much of what we call income, in the true sense of adding value from economic activity, is actually depletion instead, or the running down of natural capital."
Reply | Report Abuse | Link to thisAnd how. We've also been depleting our soil. We've been substituting fossil fuel based fertilizer for tilth. Both are running out.
There's a terrific short book about soil and how it's shaped the destiny of whole civilizations:
Dirt: The Erosion of Civilizations by David R. Montgomery
http://www.amazon.com/Dirt-Civilizations-David-R-Montgomery/dp/0520248708
(Sorry about that, I thought it would put in paragraph breaks)
Reply | Report Abuse | Link to thisHow are we going to get the current consumers of a disproportionate share of resources to share a shrinking pie with the subsistence wage earners without nuking them?
Reply | Report Abuse | Link to thisWelcome to the 8th Extinction, kiddies. We are past the tipping point. Hoping to find a way to have 8 billion humans survive on this blue marble is mental masterbation at best. All we can hope for now is that the extinction will not be as complete as the 7th, and, that we can find a way to preserve the best of human knowledge and experience on the other side of the extinction. A pessimist? No. A realist.
Reply | Report Abuse | Link to thisno he is wrong, shortage of food because of politics does in no way justify Malthus, and we know it, this article is just about the times, it is a knee jerk reaction, but that is how one becomes famous I guess with knee jerk reactions, because one is dealing with now not really looking at the situation
Reply | Report Abuse | Link to thisWhat is next? A discussion of the prophecies of Nostradamus?
Reply | Report Abuse | Link to thisBingo. The fact is, we have barely begun to tap the planet's resources. The causes of hunger and want in the world today are 100% social and political, and have nothing to do with population or scarce resources.
Reply | Report Abuse | Link to thisMental Masterbation indeed. We are at Peak Oil. The availability of cheap energy is disappearing and when it does the shiny, techno dream world we've created will crumble so quickly that billions of humans will perish. Nation states will collapse into ever smaller inclaves of folks living subsistence lives. The remenents of the world militaries will be involved in resource grabs as the powerful attempt to control what will be chaos incarnate. Malthus is right and those who listen to the warnings and learn to live an 18th century lifestyle with the ability to migrate will survive, maybe. The Party's Over kids and now is the time to think about it's clean up. What I've written here does not have to be our future (death,destruction and warfare) if we can harness our ability to empathize with each other and the world around us we may see a new and better era emerging. Just don't expect to see it on the tv for there shall be very little energyu to power that damn idiot box.
Reply | Report Abuse | Link to thisInteresting that economics courses deride Malthus. Only last month the Economist had an article entitled "Why Malthus was wrong"
Reply | Report Abuse | Link to thisStrange how the political/economics community seems to have more certainty that science will always solve food problems than the science community.
As long ago as the 1930's Alfred Whitehead pointed out that it was uncertain whether Malthus's conclusions were invalid because of science progress. Recently the geistrite does seem to have shifted to doubt the validity of the economists. Paricularly the uber free market variety
The first book I read of Malthusian doom was the Population Bomb. Any unregulated system eventually depletes the resources which led to it's growth. No organism can live in it's own waste. Looks incontrovertible to me.
Reply | Report Abuse | Link to thisThe fact that so many remain uninformed as to the INEVITABLE outcome leads me to believe that unjustified optimism is driven by the educational systems. This panders to my own sense that a subtle conspiracy has been used so that the herd fails to see the destiny which waits for us all.
Malthus used a proof that resists this blindness and which forces the sheep to look up if the sheep have the will to see their situation. It's a knife and it's directed to their ignorant throats.
The question is who profits?
Silly Sciam post, using a science-based prediction from 1798 as a basis of an Article in 2008. Well I combat it with one from 1902, Kropotkin's Mutual Aid:
Reply | Report Abuse | Link to this"... besides the law of Mutual Struggle there is in Nature the law of Mutual Aid, which, for the success of the struggle for life, and especially for the progressive evolution of the species, is far more important than the law of mutual contest."
Ignorance will subside, one day--hopefully; and cooperation will supersede those who desire "to break down the protective institutions of mutual support, with no other intention but to increase their own wealth and their own powers."
This article shows a bland acquiescence to the presence on this planet of billions of voracious members of a single species -- ours. It is time to engage in a debate as to a reasonable and responsible target level of human population, plus or minus a hundred million or so, and the best scientific and ethical ways of achieving that population level. 50 billion? Way too many. Zero? Too few. Somewhere between there may be a point we could all agree on. /signed/ terencekuch@ymail.com
Reply | Report Abuse | Link to thisTerence, et al --
Reply | Report Abuse | Link to thisRead James Lovelock's latest Gaia book. Sort of put's a lot of different things together into a comprehensive, global picture of all these different phenomina.
You may not agree with his conclusions, but, it is illuminating and thought provoking.
My issue is if the worst comes to pass, how is the best of human activity to be preserved a la the catholic monks that carried Roman - Greek - etc. writings safely to Ireland to preserve them. Another model might be found in Asimov's Foundation series -- especially the first three books.
The collision of exponentials with the finite is a mathematical certainty. It is rather amusing if economists indeed think otherwise. Predictions of the exact date of the collision are of course fraught with difficulties that can be affected by things like technology, but there are hard limits. Some of these are not even that far off.
Reply | Report Abuse | Link to this2% per year growth yields a human population of 148 trillion in 505 years, which is one person per square meter of land on Earth. I suppose we can go vertical or into the oceans.
In 613 years, 2% gives 1253 trillion people. At that point earth’s 3850 ZJ of sunlight per year (land and ocean) is insufficient to feed people, assuming 100% efficiency at converting it to food (forget about transportation, heating, or cooling...).
The mass of the Earth is an obvious upperbound for the human population, but so is the mass of the ocean, since we are mostly water. We reach that limit in 1100 years at 2% growth.
Ask your economist friends to suggest a technological fix for the mass of Earth's inhabitants exceeding the mass of the Earth. Sure, humanity may begin to colonize other planets, but the population of Earth must cease growing.
What economists need to do is start working on an Economics that does not depend upon growth. Even growth in money is an issue. Consider the gedanken in Garrett Hardin’s 1963 essay The Cybernetics of Competition: "Suppose, for example, that the thirty pieces of silver which Judas earned by betraying Jesus had been put out at 3 percent interest. If we assume these pieces of silver were dollars, the savings account would today amount to a bit more than 2 × 10^26 dollars, or 70 million billion dollars for every man, woman, and child on the face of the Earth." Now construct an Economics without compound interest...
Jeffrey Sachs wrote, "In the coming decades we will have to convert to solar power and safe nuclear power, both of which offer essentially unbounded energy supplies (compared with current energy use) if harnessed properly and with improved technologies and social controls."
Reply | Report Abuse | Link to thisOne hypothesis is that our standard of living is roughly proportional to our energy use. Let's suppose for the moment that the world population stabilizes at 11 billion in 2050, and also that the rest of the world adopts the current US 11 kW per capita energy appetite, then our worldwide usage would be 122 TW. Grow that at 2% per year (for our standard of living increase), and you reach the total solar insolation reaching the Earth in 349 years. If you try to use anything other solar, wind, or ocean energy (e.g. nuclear) to supplement insolation at that scale, then you will cause enormous global warming (yes, nuclear does raise the temperature of the Earth, though not through CO2, but rather through the blackbody effect).
We currently waste 16 kilos of cereals plus soy-bean proteins to produce one kilo of beef. If we ate less meat we could feed the 860,000,000 starving with cereals.
Reply | Report Abuse | Link to thisThe planet Earth cannot support an infinite number of people - so there IS an upper limit. We cannot sustain a growing population indefinitely.
Reply | Report Abuse | Link to thisWhether we reach that limit with the ability to sustain ourselves or if we irrevocably damage the planet and abuse all resources, causing a huge die-off, remains to be seen.
One way supports Malthus conclusion, one does not.
All you have to do is educate women. Educated women have too few children for replacement. In educated countries the population is already dieing out. Why do you think some religous groups are against female education. Humans generally create more wealth the they consume. cleptocrats-robbers will steal the producers into starvation or revolution, and a new batch of thiefs usually take over. If you want real change you may get more then you want.
Reply | Report Abuse | Link to thisMalthus theroy is founded on basic mathmatical concepts. To deride incontrivertible facts because of personal beliefs is nothing short of ignorant. A analogy of general public belief is a person who has a large (but fixed) bank balance. Yes, a given rate of spending may not seem to be a concern, for a while, but eventually will empty the account
Reply | Report Abuse | Link to thisHuman global ecophagy - the human consumption of the entire Earth - would only take a few thousand years at current growth rates. For example, a population that grows annually at 1% doubles roughly every 70 (as per the Rule of 70), a population that grows at 2% per annum doubles every 35 years, and a population that varies between 1 and 2% (inclusive) every year will double somewhere between the two. That's how our global population doubled from 3 billion in 1960 to 6 billion in 1999 (in just 39 years).
Reply | Report Abuse | Link to thisNote then that hard and fast limits to growth apply to our global population regardless of whether we grow exponentially (at a constant rate) or at variable growth rates.
Long before human global ecophagy, in just a few centuries, humanity would be like a carpet of flesh on the surface of the Earth.
Long before that, something has to give. So yes, in the coming centuries Malthusian limits to growth will apply. All technology can do is buy us a little time and allowthe problem (our global population) to get bigger and bigger.
Global warming is nothing compared to what we will experience due to even partial human global ecophagy.
A prediction that takes 200+ years to come true is not much of a prediction
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