CHAPTER 2 Overpopulation– the modern denial The word overpopulation was brought into the modern pub- lic consciousness in 1968 by a book called The Population Bomb written by Paul Ehrlich. The book was a warning to the world that the human population was a ticking time bomb about to explode. The book badly missed the mark with its predictions of resource shortages and famine. For example, Ehrlich predicted that four billion people would starve to death in the 1980s. Based on that prediction, he also called for some highly unpopular measures to reduce our population growth. To ice the cake, he made a bet with an economist named Julian Simon about the price of five metals over a ten-year period. Ehrlich said the price would go up as a result of dwindling resources and Simon said the price would drop. The price dropped. Ehrlich paid up. W hy Ehrlich thought that new sources for those metals would not be found or that manufacturers would not make compromises to compensate for shortages is beyond me. As an engineer at Boe- ing, I often altered a design to use high strength aluminum instead of titanium because the cost of titanium was too high. At one time, most sources of titanium were in the Soviet Union. W e used titanium extensively after the fall of the Berlin wall. I recently met Paul Ehrlich at a signing for his latest book One with Nineveh. I listened to him speak for an hour. He is an impressive figure, tall, vigorous, with a deep voice and a tre- mendous sense of humor. I was very impressed. Anyone who makes the mistake of predicting human trends with precision is asking for trouble. One can predict with relative certainty that the stock market will crash or boom, but you would be rash to say when those things will happen or to what extent. People with a propensity for betting are going to lose once in a while. Simon‘s betting record wasn‘t flawless. In 1997 he paid $1000 to David South, a professor at Auburn University, over the predicted price of pine sawtimber.1 That‘s the problem with gambling, you have to stop when you‘re ahead. A later book, The Population Explosion, published in 1990 by Ehrlich and his wife, Anne, did a much better job document- ing the havoc wreaked upon the planet by our huge numbers. The title of the book suggests that the population bomb has gone off, and evidence of that blast can be seen everywhere. The population growth advocates point out that because of improved technology, food production presently outstrips popu- lation growth. They also believe that resource shortages will always be compensated for with new technologies. However, they are making the same mistake that the Ehrlichs made. They are extrapolating what exists today into the future. In 1968, the same year that The Population Bomb was pub- lished, with a third of the world hungry, and with the percentage of world population growth maxed-out at about 2.1 percent, it looked like Ehrlich's concerns were dead on. The Ehrlich's had assumed that because a third of the planet was already hungry we had reached the limits of our ability to feed ourselves. Logi- cally, this left only one option, reducing population growth. Coincidentally, 1968 was also the last year to see an increase in the percentage of world growth– not total growth– and was the start of a decline in percentage of growth that continues to this day– see Figure 1. However, predictions of extremely rapid population growth held true and Ehrlich‘s predictions of mass starvation would also have panned out if our food supply had not unexpectedly increased even more rapidly than our population. Although the percentage of population growth began to de- crease in 1968, the actual number of people being added every 1 http://www.forestry.auburn.edu/sfnmc/web/bet.html Overpopulation– the modern denial 3 year continued to increase as a result of population momentum reaching a peak of about 87 million in 1989– see Figure 1. Again, by coincidence, this was the same year that the Popula- tion Explosion was published and also marked the start of a decline in the number of people added every year that continues to this day. Approximately 75 million people were added to the world population in 2003. Year Population Growth # added per year 1964 3,276,816,764 2.08% 69,021,089 1965 3,345,837,853 2.08% 70,227,393 1966 3,416,065,246 2.02% 69,742,104 1967 3,485,807,350 2.04% 71,868,340 1968 3,557,675,690 2.08% (Bomb) 74,665,661 1969 3,632,341,351 2.05% 75,268,761 1970 3,707,610,112 2.07% 77,580,647 1971 3,785,190,759 2.01% 77,006,527 1972 3,862,197,286 1.96% 76,511,302 1973 3,938,708,588 1.91% 75,889,828 1974 4,014,598,416 1.82% 73,625,631 1975 4,088,224,047 1.75% 72,167,756 1976 4,160,391,803 1.73% 72,536,792 1977 4,232,928,595 1.70% 72,474,692 1978 4,305,403,287 1.74% 75,373,540 1979 4,380,776,827 1.72% 75,928,390 1980 4,456,705,217 1.70% 76,259,715 1981 4,532,964,932 1.76% 80,436,954 1982 4,613,401,886 1.73% 80,530,264 1983 4,693,932,150 1.68% 79,634,655 1984 4,773,566,805 1.68% 81,036,085 1985 4,854,602,890 1.70% 83,004,818 1986 4,937,607,708 1.73% 85,962,468 1987 5,023,570,176 1.71% 86,583,085 1988 5,110,153,261 1.67% 86,179,948 1989 5,196,333,209 1.67% 87,422,136(Explosion) 1990 5,283,755,345 1.56% 83,182,744 1991 5,366,938,089 1.53% 82,725,730 1992 5,449,663,819 1.48% 81,337,993 1993 5,531,001,812 1.44% 79,976,536 1994 5,610,978,348 1.41% 79,887,428 1995 5,690,865,776 1.36% 77,746,508 1996 5,768,612,284 1.35% 78,192,518 1997 5,846,804,802 1.32% 77,770,099 1998 5,924,574,901 1.31% 77,934,526 1999 6,002,509,427 1.29% 77,632,256 2000 6,080,141,683 1.26% 77,258,877 2001 6,157,400,560 1.24% 76,849,827 2002 6,234,250,387 1.22% 76,299,210 2003 6,310,549,597 1.19% 75,477,418 2004 6,386,027,015 1.16% 74,526,549 Figure 1: Population Data Source: U.S. Bureau of the Census, International Database. Following is an example of how the percentage of growth can fall but the total population can continue to grow. Assume you have 10,000 mice and their population grew by 10 percent in a mouse year. That would give you 1,000 more mice for a total population of 11,000 mice (0.1 x 10,000=1,000). The next mouse year the population increased only 9.9 percent adding 1089 mice (0.099 x 11,000=1,089). You can see that 89 more mice were added the following year than the previous because 9.9 percent of 11,000 is a bigger number than 10 percent of 10,000. The percentage of growth today is about 1.2 percent– see Figure 1. Ehrlich‘s predictions missed their marks for several reasons. Keep in mind that everything I am about to say is in hindsight. Many things have come to light in the last 36 years that explain why the predictions never panned out. They were not part of the debate in 1968. First, it has long been assumed that human population grows exponentially. To this day, if you search the Internet for the definition of exponential growth the authors will invariably use population growth as an example. Anyone who has had a course in biology knows the age-old example of lily pads on a pond. The most elegant version of this I have ever heard came from E.O. W ilson in his book Consilience: "A lily pad is placed in a pond. Each day thereafter the pad and then all of its descendants double. On the thirti- eth day the pond is covered completely by lily pads, which can grow no more. On which day was the pond half full and half empty? The twenty-ninth day." W hen each pad on the twenty-ninth day replicated itself, collectively, they covered the rest of the pond. In this case the analogy is an attempt to describe the rate at which humanity is destroying the planet‘s biodiversity, not the usual description of human population growth. Overpopulation– the modern denial 5 I am going to try to explain this without– as the young bucks I play basketball with would say– "getting mathematical on your ass." The most common example of exponential growth that almost everybody understands is an interest bearing savings account. If you plot the growth of your account over time you will eventually see the "j" shaped curve characteristic of expo- nential growth. However, if you closely inspect the shape of the actual human population growth curve– as opposed to a theo- retical one– you will discover that it does not look like it was generated by exponential growth.