Overpopulation and the Environment: We Must Act Now
Is the planet doomed? The short answer is no, we're not doomed, since the verb implies inevitability. (1) Population is not growing everywhere, and the areas where growth rates are near zero or even negative (such as the United States and Western Europe) provide clues to addressing the problem in other regions. The longer answer to the doom question is that growing population is a problem that left unsolved could indeed have very harmful effects, both on the environment and our current life styles. However, controlling population growth rates is a relatively simple task compared to the even more critical problem of curbing seemingly insatiable desires for consumption. It is the quest for an ever-increasing standard of living that really holds our potential doom.
At this point in the debate, the doom scenario is very familiar. Pessimists from Malthus to Meadows (2) (and his Limits to Growth and Beyond the Limits study teams) have despaired at humankind's inevitable collapse, brought on by exploding population, growing geometrically, that overwhelms a finite planet whose natural resources are fixed and whose food supply only grows arithmetically.
However, there are a number of factors not taken into account in pessimistic models' predictions of increasing resource scarcity. (3) Malthus' original predictions not only ignored the possibility of technological change, but also were created with the goal of persuading people to act morally and reduce the numbers of children they had. Meadows and his team built their systems dynamics model using dominantly positive feedback loops, (4) which may have biased their conclusions. More importantly, their approach assumed that consumption patterns continued unchanged as scarcity increased. This assumption, by ignoring the effects of substitution of one resource for another and technological developments, ignores the natural negative feedback systems inherent in a market system. If markets are working properly (which is a separate problem), the price of a resource will rise as that resource becomes scarcer. Rising prices encourage people to switch their consumption patterns away from the scarce resource towards a cheaper substitute resource. Price increases also stimulate research that may produce technologies that can allow people to do more with the same amount of resources. Although there is not always a "tech-fix," sometimes there is. More importantly, rising prices can make existing technologies relatively cheap enough to be viable. For instance, a rise in the price of oil may make hybrid cars relatively cheaper, allowing them to become more widespread.
The other failing of these pessimistic models is in their conclusion that continuing population growth is inevitable. A phenomenon called the demographic transition (5) has been observed to occur as nations develop and standards of living rise. Before a nation develops, birth and death rates...