When We "Hit the Wall"

by Roy W. Brown

The following article is from Free Inquiry magazine, Volume 19, Number 2.

In a recent article in Science, John Bongaarts of the Population Council in New York wrote about the demographic impact of falling fertility rates. [1] Average human fertility has been falling steadily for the past 30 years, from six or seven children per woman in the early part of this century to just three or four children per woman today. But that number is still well above replacement level - so each human generation is still bigger than the last. As Sergei Kapitsa and others have shown, for many centuries world population has approximated more closely hyperbolic growth as opposed to the exponential growth foreseen by Malthus - in other words, an explosion. [2] From just 1.7 billion in 1900 our population will top 6 billion sometime this year. The latest U.N. projections [3] show population continuing to rise at least until the middle of the twenty-first century and possibly beyond, with another 3 billion mouths to feed within the next two or three generations.

But, as the Worldwatch Institute has pointed out, the U.N. projections are based purely on current demographic trends and take no account of the ability of the Earth's resources to sustain humanity in such numbers. [4] Will the outcome be a hard or a soft landing for humanity? Current indications are that, for some of us at least, the landing will be very hard indeed.

A Crash in the Distance

Ninety percent of future population growth is projected to occur in the poorest countries and among the societies least able to cope. The industrialized nations, the "North," have all experienced the demographic transition from the historically high birthrate, high death-rate of pre-industrial society, through a second stage of rapid population growth with high birthrate but increasing life expectancy, to the present stage with birthrates at or below the replacement level of 2.1 children per woman. For these societies long life is the norm and populations are relatively stable.

Over the next 50 years Europe will see its population stabilize or decline slightly as individual couples exercise their choice of having smaller families. Most countries in the developing world, in contrast, are still at the unsustainable second stage of transition with rapidly growing populations. The challenge for these countries is whether they can reduce their population growth rates fast enough to reach the sun-lit uplands of stability or whether they will fall back into the demographic trap where population growth outstrips the pace of economic development, leading to increasing poverty, sickness, and starvation, increasing maternal and infant mortality, and possibly even to social breakdown. For these societies, what has even more impact than the absolute numbers is the rate of population growth, in some countries as high as 3% per year. That may not sound like much, but it means they face a doubling of population in under 25 years. Imagine being dirt poor, yet having to meet a demand for more food, more clean water, more housing, more sanitation, more hospitals, more jobs, and so on every year, year after year. It simply doesn't happen. Some cities in Asia and Latin America have actually seen their slums grow at over 6% a year.

Reducing the national rate of population growth is now recognized by the governments of all developing countries as a key to their future economic development, but for many of them this recognition may have come too late. Life expectancy is already falling in large parts of Africa as a result of the AIDS epidemic, and birthrates may well remain high because individuals have neither the means nor any good reason to limit the number of their children. For countries in the demographic trap the prospects are truly bleak, and for those with populations already in excess of their long-term carrying capacity there may be no way they can avoid an eventual population crash.

At the global level and in the longer term the outcome will be decided by the impact we collectively make on our environment. We in the rich North have an unprecedented capacity for environmental damage. We each consume as much energy, use as much water, and create as much waste as about 40 people living in sub-Saharan Africa. We often hear the argument that what is ruining the planet is not population growth in the South but our profligate life-styles in the North. Unfortunately that argument breaks down as economic development in the South begins to provide exactly the kind of high-consumption life-style we already enjoy. So our total impact on the planet is a matter of both population numbers and the average environmental impact each of us makes.

How many people can Earth support indefinitely? It depends entirely on consumption. If we all shared the low-impact life-style of an African or Indian, Earth could perhaps support 10 billion of us indefinitely. But with a typical North American way of life the figure has been shown to be closer to 2.5 billion - and there are already 6 billion of us on Earth. The late Julian Simon argued that population growth was a good thing; that by any measure you care to choose life has gotten better as our population has grown, and that it will therefore continue to do so. Unfortunately, it isn't possible to draw that conclusion. Quite apart from the fact that there are measures by which life has most assuredly become more difficult, the problem is that the resources of our planet - even the renewable resources - are finite, and some, such as fresh water, cannot be substituted. (See Lester Brown's article on just how stressed some of our resources are becoming.)

How Will It End?

The big question is: Will we learn to live within our limits, and what will happen if we don't?

There are some good historical examples of what happens when population growth and consumption outstrip the available resources. Easter Island is one that springs to mind. When the island was first visited by Westerners in the seventeenth century, there was evidence that it had once supported a far higher population and a higher level of civilization than was then in evidence. In fact, it was thought that the island had once been inhabited by a race of supermen. Research has revealed that a once-flourishing society on a green and pleasant island outgrew its resources. Tree cover disappeared, rainfall was reduced, and finally bitter conflict over the diminishing food and water supply led to a population crash to perhaps only 10% of the number the island had once supported. Almost all projections for future world population growth show it stabilizing at some point in the future. While this may happen, it is not the most likely scenario. Human population and Earth's resource base form a nonlinear dynamic system. Such systems are typically chaotic and rarely, if ever, achieve stability. A more probable outcome is for world population, like that of Easter Island, to overshoot its level of long-term sustainability and then crash as crucial resources become exhausted and environmental degradation sets in. Only global agreement and collective action on both population and the environment seem likely to avert this outcome.

So how will it all end? It's in our hands. We, the inhabitants, consumers, and voters of the rich countries of the North will determine the final outcome - either by our actions, or by our inaction. As a minimum we should urge our governments to honor the commitments they made at the International Conference on Population and Development in Cairo to do more to help fund family planning programs in developing countries - and to start to take more seriously the environmental impact of our collective life-style. If we don't act now, our grandchildren - even if they survive - will never forgive us.

Roy W. Brown is founder, board member, and former chairman of the World Population Foundation in the Netherlands.

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