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The Limits to Growth is a 1972 book modeling the consequences of a rapidly growing world population and finite resource supplies, commissioned by the Club of Rome. Its authors were Donella H. Meadows, Dennis L. Meadows, Jørgen Randers, and William W. Behrens III. The book used the World3 model to simulate[1] the consequence of interactions between the Earth's and human systems. The book echoes some of the concerns and predictions of the Reverend Thomas Robert Malthus in An Essay on the Principle of Population (1798). Five variables were examined in the original model, on the assumptions that exponential growth accurately described their patterns of increase, and that the ability of technology to increase the availability of resources grows only linearly. These variables are: world population, industrialization, pollution, food production and resource depletion. The authors intended to explore the possibility of a sustainable feedback pattern that would be achieved by altering growth trends among the five variables. The most recent updated version was published on June 1, 2004 by Chelsea Green Publishing Company and Earthscan under the name Limits to Growth: The 30-Year Update. Donnella Meadows, Jørgen Randers, and Dennis Meadows have updated and expanded the original version. They had previously published Beyond the Limits in 1993 as a 20 year update on the original material.[2][3][4] In 2008 Graham Turner at the Commonwealth Scientific and Industrial Research Organisation (CSIRO) in Australia published a paper called "A Comparison of `The Limits to Growth` with Thirty Years of Reality".[5][6] It examined the past thirty years of reality with the predictions made in 1972 and found that changes in industrial production, food production and pollution are all in line with the book's predictions of economic and societal collapse in the 21st century.[7]
[edit] PurposeThe purpose of The Limits to Growth was not to make specific predictions, but to explore how exponential growth interacts with finite resources. Because the size of resources is not known, only the general behavior can be explored. The authors state in a subsection titled The Purpose of the World Model[8]:
[edit] Exponential reserve indexOne key idea that The Limits to Growth discusses is that if the rate of resource use is increasing, the amount of reserves cannot be calculated by simply taking the current known reserves and dividing by the current yearly usage, as is typically done to obtain a static index. For example, in 1972, the amount of chromium reserves was 775 million metric tons, of which 1.85 million metric tons were mined annually (see exponential growth). The static index is 775 / 1.85 = 418 years, but the rate of chromium consumption was growing at 2.6% annually (Limits to Growth, pp 54–71). If instead of assuming a constant rate of usage, the assumption of a constant rate of growth of 2.6% annually is made, the resource will instead last (note that the book rounded off numbers). In general, the formula for calculating the amount of time left for a resource with constant consumption growth is : where:
The authors list a number of similar exponential indices comparing current reserves to current reserves multiplied by a factor of five:
The static reserve numbers assume that the usage is constant, and the exponential reserve assumes that the growth rate is constant. For petroleum, neither the assumption of constant usage or the assumption of constant exponential growth was correct in the years that followed. Whether intended or not, the exponential index has often been interpreted as a prediction of the number of years until the world would "run out" of various resources, both by environmentalist groups calling for greater conservation and restrictions on use, and by skeptics criticizing the index when supplies failed to run out. For example, The Skeptical Environmentalist (page 121) states: "The Limits to Growth showed us that we would have run out of oil before 1992." What The Limits to Growth actually has is the above table, which has the current reserves (that is no new sources of oil are found) for oil running out in 1992 assuming constant exponential growth.[9][10][11] [edit] Criticism
The Limits to Growth attracted controversy as soon as it was published. Robert M. Solow from MIT, complained about the weak base of data on which The Limits to Growths predictions were made (Newsweek, March 13, 1972, page 103). Dr. Allen Kneese and Dr. Ronald Riker of Resources for the Future (RFF) stated:
Some critics falsely claimed that The Limits to Growth predicted oil running out in 1992 among other natural resources. The book's real conclusion was that it was very unlikely that resources would end in 1992. The 1992 date was extrapolated out of context by critics dedicated to demolish "Limits" work, and is still present in common knowledge. It should be noted, that the authors of the report accepted that the then-known resources of minerals and energy could, and would, grow in the future, and consumption growth rates could also decline. The theoretical expiry time for each resource would therefore need to be updated as new discoveries, technologies and trends came to light. To overcome this uncertainty, they offered an upper value for the expiry time, calculated as if the known resources were multiplied by two. Even in that case, assuming continuation of the average rate of consumption growth, virtually all major minerals and energy resources would expire within 100 years of publication (i.e., by 2070). Even if reserves were two times larger than expected, ongoing growth in the consumption rate would still lead to the relatively rapid exhaustion of those reserves.[13] On the other hand, reserves may continue to grow, considering the large amounts of minerals in the planet Earth. In 2008 researcher Peter A. Victor wrote, that even though D.H. Meadows et al. probably paid too little attention for price-mechanism's role in adjusting, their critics have paid too little. He states that Limits to Growth has had a huge impact on how we still think about environmental issues and notes that the models in the book were meant to taken as predictions "only in the most limited sense of the word" as they wrote.[14] Yale economist Henry C. Wallich labeled the book "a piece of irresponsible nonsense" in a Newsweek editorial dated March 13, 1972. Wallich's main complaints are that the book was published as a publicity stunt with great fanfare at the Smithsonian in Washington, and that there was insufficient evidence for many of the variables used in the model. According to Wallich, "the quantitative content of the model comes from the authors' imagination, although they never reveal the equations that they used." Considering that the detailed model and Meadows' et al. justifications were not published until 1974 (two years after The Limits to Growth) in the book Dynamics of Growth in a Finite World, Wallich's complaint about "the peculiar presentation of their work and by their unscientific procedures" had merit at the time. [edit] See also
[edit] Books
[edit] References
[edit] Editions
[edit] External links
[edit] Video and Audio
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