The Limits to Growth is still “as wrongheaded as it is possible to be.”
Cassandra in Greek mythology was the Trojan priestess who was cursed to utter true prophecies but never to be believed. Ideological environmentalism features a cohort of reverse Cassandras: They make false prophecies that are widely believed. Stanford biologist Paul Ehrlich in his 1968 classic, The Population Bomb, prophesied, „The battle to feed all of humanity is over. In the 1970s hundreds of millions of people will starve to death in spite of any crash programs embarked upon now.“ Ehrlich continues to predict imminent overpopulation doom. Another reverse Cassandra was Rachel Carson who warned in her 1962 Silent Spring of impending cancer epidemics sparked by humanity’s heedless use of synthetic pesticides. In fact, even as pesticide use has risen, rates of cancer incidence and mortality have been falling for 30 years. On the occasion of the 53rd Earth Day, let’s take a look at the prophecies of another reverse Cassandra, the Club of Rome’s 1972 The Limits to Growth report by Donella Meadows, Dennis Meadows, Jorgen Randers, and William Behrens. The book and its dire forecasts were introduced to the world at a March 1972 conference at the Smithsonian Institution. Let’s focus primarily on the report’s nonrenewable resource depletion calculations. The 1973 oil crisis was widely taken as confirming the book’s dire scenarios projecting imminent nonrenewable resource depletion. Back in 1989, I spent the day at the Massachusetts Institute of Technology (MIT) talking with some of the folks who had put together The Limits to Growth, especially with Jay Forrester, who had devised the World 2 systems dynamics computer model. The Limits to Growth team developed a modified version of Forrester’s model that they dubbed World 3 upon which the report chiefly relied for its findings. In the first chapter of the book, the researchers were particularly interested in and concerned about the nature of exponential growth. „Nearly all of mankind’s current activities,“ they wrote, „can be represented by exponential growth.“ Exponential growth occurs when something is increasing or growing rapidly as a result of a constant rate of growth applied to it. Compound interest is an example of exponential growth. In the second chapter on the limits to exponential growth, the researchers asked, „What will be needed to sustain world economic and population growth until, and perhaps, even beyond, the year 2000?“ The „physical necessities“ included food, raw materials, and fossil and nuclear fuels. The researchers aimed to „assess the world’s stock of these physical resources, since they are the ultimate determinants of the limits to growth on this earth.“ On October 16,1989, Forbes published my article „Dr. Doom.“ Using data from the report’s Table 4 on global 1972 nonrenewable resource reserves and expected future rates of consumption, I calculated how much longer the global reserves estimated by the MIT team would last. “ Limits to Growth predicted that at 1972 rates of growth the world would run out of gold by 1981, mercury by 1985, tin by 1987, zinc by 1990, petroleum by 1992, copper, lead and natural gas by 1993,“ I wrote. The depletion dates I cited simply came from reading those data right off of their exponential index years listed in column 5 in Table 4. As they explained in a footnote to Table 4, their column 5 calculations represent „the number of years known global reserves will last with consumption growing exponentially at the average annual rate of growth.“ As an example, the authors calculated that at the current rate of consumption global supplies of copper would last 36 years but applying the annual average rate of growth in copper consumption of 4.6 percent yielded the result that known global copper reserves would be used up in only 21 years. So at the exponentially increasing rates of consumption that the researchers fully expected to ensue, known reserves in 1972 of gold would be depleted in nine years; mercury in 13 years; tin in 15 years; zinc in 18 years; petroleum in 20 years; and copper, lead, and natural gas in 22 years. As I reported in my Forbes article when I asked Forrester about these figures, he told me, „I think in retrospect that Limits to Growth overemphasized the material resources side.“ Well, yes. However, The Limits to Growth, remains something of a sacred text to certain 21st-century prophets of impending resource doom. For example, the “ peak oil “ panic at the beginning of this century later morphed into a “ peak everything “ frenzy. One especially avid defender of The Limits to Growth faith is University of Florence physical chemist Ugo Bardi.
