The trend of destiny: The impossibility of population growth

Today has been designated the birthday of the planet’s seven-thousand-millionth person, perhaps in a village in Upper Volta, or maybe an apartment in Lower Manhattan. How many billion more?

By 2050, Australia will have between 29 and 43 million people, but we will still be a very small fish in a global pond with at least nine billion other folk.

Our 2011 census was held precisely one hundred years after the first national census. Carried out under Commonwealth Statistician, Sir George Handley Knibbs, on 3^rd April 1911, it was part of an ambitious project to count the British Empire’s international population, then about 400 million people.

A century ago, there were about 4,455,000 Australians. Four times larger today, the population reached 22,726,000 early this month. With one birth every 1 minute and 46 seconds, one death every 3 minutes and 40 seconds, a net gain of one immigrant every 2 minutes and 44 seconds, we are adding one new person each 1 minute and 31 seconds

Why were censuses held in 2011 and 1911, and not 2010 and 1910? It was an accident of history. The UK’s first modern census was taken in 1801. It was a policy response to Thomas Robert Malthus’s controversial first book:  An Essay on the Principle of Population, as it affects The Future Improvement of Society.  A national census has been held every decade since 1911, except during World War II.

In his 1798 Essay, Malthus argued the rate of human population growth would inevitably stall progress towards a more “perfectible” society: "The power of population,” he wrote, “is indefinitely greater than the power in the Earth to produce subsistence for man. Population, if unchecked, increases in a geometrical ratio. Subsistence increases only in an arithmetic ratio. A slight acquaintance with numbers will show the immensity of the first power in comparison of the second”. For him, this Principle was a law of Nature, divinely imposed to ensure virtuous behaviour.

Hidden in Volume One of Knibbs’s Statistician’s Report on the 1911 Census is his eerily prophetic Appendix A: The Mathematical Theory of Population, of its character and fluctuations, and of the factors which influence them. Like Malthus, he was emphatic about humankind’s “trend of destiny”: the impossibility that population could go on increasing at its present growth rate for a “long-continued” period.

The trend of destiny: Anyone who has seriously reflected on the facts of the last ten decades, must realise that, within the next ten, tremendous problems will arise for solution and these will touch fundamentally the following matters: the multiplying power of the human race; the organic constitution of Nature and the means at human disposal for avoiding the incidence of its unfavourable aspects; the enhancing of the productivity of Nature, and the limits of its exploitation; the mechanism of the social organism, and the scheme of its control; and internationalism and the solidarity of humanity. 

 “The limits of human expansion are much nearer than popular opinion imagines,” he concluded, echoing The Limits to Growth (1972) and other eco-manifestos. “The difficulty of future food supplies will soon be of the gravest character; the exhaustion of sources of energy necessary for any notable increase of population or advance in the standards of living, or both combined, is perilously near.”

Knibbs’s estimate of the planet’s population in 1900 was 1,700 million, with an annual rate of increase of about 1.16 percent. If this rate continued for another 100 years, he calculated there would be 3.16 times as many people by 2011, or 5,380 million. (It actually reached 7,000 million this year, a four-fold increase in 111 years.)

For him, the mathematics was undeniable. “Very soon,” he warned, “the world-politic will have to face the question whether it is better that there should be larger numbers and more modest living, or fewer numbers and lavish living; where world-morality should aim at the enjoyment of life by a great multitude; or aim at the restriction of life-experience to a few, that they may live in relative opulence.”

The statistician’s role would be to enlighten governments about the “trend of destiny” in “a world of limitations.” Only knowledge of demographic trends would enable them to see the seriousness of the situation. His concern, however, was not (yet) shared by the world-politic, especially his contemporaries in Europe, where declining birth-rates had reversed fears of over-population since Malthus.

A decade later, Knibbs published another work forgotten today, his magnum opus: The Shadow of the World’s Future – Or the Earth’s Population Possibilities and the Consequences of the Present Rate of Increase of the Earth’s Inhabitants.

“Founded upon a survey of its areas, of the distribution of its present inhabitants, and of their productions, it shows that the menace of the present rate of growth of those inhabitants is most serious,” he wrote in the preface. “This rate is of the order of about one percent per annum. Starting in 1928 with a total of say 1,950 millions of human beings, the existence of such a rate is of the gravest significance, for, in the course of the present century, mankind will be involved in very great difficulties, for which unquestionably it is quite unprepared.”

He made crude estimates of the planet’s “population-carrying power” under four scenarios, based on population densities in various countries at the time and other variables. “The numbers of human beings which the world-surface can carry,” he concluded, “is limited to a relatively small multiple of the existing population.”

Assuming the estimated annual Western world growth rate of 1.16 percent prevailed over the globe, his hypothetical maximum populations of 5,200 million, 7,020 million, 9,000 million and 11,000 million would be reached, respectively, in 85 years (2013), 111.1 years (2039), 132.6 years (2061) and 150 years (2078).   

On Asia: “If, as appears to be beginning already, the multitudes of the East should westernise their conceptions as to what constitutes a reasonable standard of living, the population-problem is at once raised to a plane of greater difficulty. On the other hand, if western races ever abandon their present love of what may seem to some inordinate luxury, and all useless complication of the paraphernalia of social life, it is certain that the population difficulty, for a time at least, will diminish.”

Yet there was “no adequate world-reaction” to the population problem. Knibbs urged a radical change of perspective, of consciousness. What was required was “the attention of every country that can influence the issue.”

How many billion more? Last July, the U.K. Royal Society made a surprise announcement. It launched a major study into a “hugely controversial area” - anthropogenic population growth - to determine how demographic trends might affect development this century.

The announcement was made on World Population Day, July 11^th, 2010. This annual event began in 1989, when the U.N. decided to commemorate the world’s first Five Billion Day, reached in 1987. Almost two and a half decades later, the population had surged by 39 per cent to seven billion this year.

Nevertheless,the agency’s policy focus shifted away from concern over global growth rates to other issues - especially climate change. In its latest report, State of World Population 2011, released this week, the U.N. continues to insist we should no longer be asking "are we too many", but concentrate instead on making the world “better”.

Yet we are now adding the largest numbers in our history. Despite a decline in the global growth rate to about an annual 1.2 percent, demographic momentum is producing an additional 83 million people each year, mostly in the developing world.

By 2025, the world population is projected to reach eight billion. Previous estimates that it would peak around nine billion between 2045 and 2050 now seem unlikely. New U.N. projections suggest it could be as high as 10.6 billion by mid-century. The actual outcome depends on several key variables; with total fertility rates per woman (TFRs) over the next four decades especially critical.

The UN Population Division produced six projections in April this year for the 44^th session of U.N. Commission on Population and Development. In its “medium” scenario, world population would peak at 9.4 billion in 2070 and then start to decline, but only if fertility declines significantly in most developing countries. The high scenario, where fertility remains mostly between 2.2 and 2.3 children per woman, would lead to a world population of nearly 15 billion in 2100, 20 billion in 2200 and 30 billion in 2300.

Hania Zlotnik, the Division’s Director, recently warned that “high-fertility countries may not reduce their fertility fast enough. Even countries with intermediate fertility need to reduce it to replacement level or below to avert continuous population increases to unsustainable levels.”

Ominously, the Population Reference Bureau’s global TFR seems stuck at 2.5 (Africa 4.7), significantly higher than the desired replacement rate of 2.1. Half a TFR unit is the difference between the U.N.'s medium and high projections, and represents about 5 billion extra people by 2100. Can the global population be stabilised humanely before the end of the century, or will it be reduced by Malthusian checks of famine and conflict?

How too, and why, was this cause celebre of the 1960s and 1970s – anthropogenic population growth - displaced by “dangerous” anthropogenic climate change as the “greatest moral challenge of our time”?  That, as they say, is another story.