The following are several lightly edited excerpts from a longer article of the same title. If you would like an electronic copy of the original article, please e-mail your request to our Office Manager, Carolyn VandenDolder, at Carolyn@WorldPopulationBalance.org
My position is simply stated. Within the next half-century, it will be essential for the human species to have fully operational a flexibly designed, broadly equitable and internationally coordinated set of initiatives focused on reducing the then-current world population by at least 80%. Given that even with the best of intentions it will take considerable time and exceptional diplomatic skill to develop and implement such an undertaking, perhaps on the order of 25 to 50 years, it is important that the process of consensus building - local, national and global - begin now. The mathematical inevitability that human numbers will continue their dramatic increase over the next two generations, to perhaps 9 billion by the year 2050, and the high probability that this numerical increase will exacerbate still further the systemic problems that already plague humanity (economic, political, environmental, social, moral, etc.), only reinforces this sense of urgency. There are, however, hopeful signs. In recent years, we have finally begun to come to terms with the fact that the consequences of the 20th century’s rapid and seemingly uncontrolled population growth will soon place us - if it hasn’t already done so - in the midst of the greatest crisis our species has yet encountered.
I therefore argue that over the next several generations, and beginning as soon as possible, humanity must not only take significant steps to arrest the rapid growth of human population but also begin to reduce it dramatically. However, it will be very difficult if not impossible to stop current growth short of 9 to 10 billion. This is due not only to demographic momentum but also to the great difficulties, both diplomatic and temporal, in developing and implementing the necessary political, economic, scientific and moral consensus about both ends and means.
Because there is no clear-cut evidence to support assertions to the contrary, and precious little margin for error, it is only prudent to work from the increasingly legitimate assumption that the earth’s long-term carrying capacity is no greater than two billion people, at what might be characterized as an “adequate” first world standard of living, perhaps on the level of Spain, Italy, or Taiwan. It is therefore necessary to confront the inescapable fact that human numbers will have to be reduced by 80% or more, from the allbut- inevitable 9-plus billion in the mid- 21st century to something approaching 2 billion by the end of the 22nd century, some 200 years from now. Obviously, a numerical dislocation of this magnitude will require a massive reorientation of human thought, expectations, values, and lifestyles.
Just as obviously, time is short, with an implementation window that will last no more than the next 50 to 75 years, and perhaps considerably less. This process of population stabilization and reduction should have begun a generation or more ago - say in 1960 when human numbers were “only” three billion and demographic momentum more easily arrested - and certainly cannot be delayed much longer. For it is abundantly clear that if we do not choose to address and resolve this problem ourselves, “nature” will almost certainly solve it for us, with consequences that would be at best unpredictable and at worst unimaginable.
The problem of establishing rational and defensible population “optimums” deserves further comment. Perhaps most surprising is how unusual it is to find individuals - or organizations - who are willing to state publicly and emphatically that just reaching a point of “population stability” during the next century will not be enough, either to solve our near-term demographic difficulties or to stave off a future demographic catastrophe. For the latter scenario will almost surely come to pass if humanity naively and/or unquestioningly accepts global population levels that are set so high - in the 10 to 12 billion range - that they are clearly unsustainable over the longer term. One only has to consider the stresses already evident at the current level of almost 6.7 billion to recognize that any sort of longterm stability at figures nearly double that number will be impossible to accomplish. Put most simply, there seems to be no credible alternative to the premise that a very significant population reduction must necessarily follow population stabilization.
Actually, this two billion estimate may be somewhat on the generous side, particularly in light of the fact that some recent projections for the earth’s longterm carrying capacity have been set much lower, in the one-half to one billion range, particularly if the normative lifestyle (level of consumption) aspired to is anywhere close to that of the United States.
On the other hand, even if future research shows that this global carrying capacity figure has been underestimated by at least l/2 - that is, if further analysis demonstrates that an optimum population estimate of two billion is “off-target” by a factor of two or more - the argument put forth here loses little if any of its validity or persuasive power. For example, even a population optimum in the four billion range would still require a significant decrease in global human numbers, roughly on the order of 60%.