5/15/2018 The Limits to Growth - Wikipedia The Limits to Growth The Limits to Growth (LTG) is a 1972 report[1] on the computer simulation The Limits to Growth of exponential economic and population growth with a finite supply of resources.[2] Funded by the Volkswagen Foundation[3] and commissioned by the Club of Rome, the findings of the study were first presented at international gatherings in Moscow and Rio de Janeiro in the summer of 1971.[1]:186 The report's authors are Donella H. Meadows, Dennis L. Meadows, Jørgen Randers, and William W. Behrens III, representing a team of 17 researchers.[1]:8 Since its publication, some 30 million copies of the book in 30 languages have been purchased.[4] It continues to generate debate and has been the subject of several subsequent publications.[5] Most recently, The Limits to Growth: The 30-Year Update was published on June 1, 2004.[6] The Limits to Growth first edition cover. Contents Authors Donella H. Meadows Dennis L. Meadows Purpose Jørgen Randers Methodology Exponential reserve index William W. Behrens III Conclusions (https://www.revisionen Criticism ergy.com/staff/william-b ehrens-phd) Positive reviews Legacy Language English Related books Published 1972 Editions Publisher Potomac Associates - See also Universe Books References Pages 205 External links ISBN 0-87663-165-0 OCLC 307838 (https://www.wo Purpose rldcat.org/oclc/307838) digital: Digitized 1972 edition (http://colle In commissioning the MIT team to undertake the project that resulted in LTG, ctions.dartmouth.edu/teitexts/meadows/ [1]:185 the Club of Rome had two objectives: diplomatic/meadows_ltg-diplomatic.htm l) 1. Gain insights into the limits of our world system and the constraints it puts on human numbers and activity. 2. Identify and study the dominant elements, and their interactions, that influence the long-term behavior of world systems. https://en.wikipedia.org/wiki/The_Limits_to_Growth 1/10 5/15/2018 The Limits to Growth - Wikipedia Methodology The study used the World3 computer model to simulate the consequence of interactions between the earth and human systems.[7][8] The model was based on the work of Jay Forrester of MIT,[1]:21 as described in his book World Dynamics.[9] The model was based on five variables: "population, food production, industrialization, pollution, and consumption of nonrenewable natural resources".[1]:25 At the time of the study, all these variables were increasing and were assumed to continue to grow exponentially, while the ability of Logo of the Club of Rome. technology to increase resources grew only linearly.[1] The authors intended to explore the possibility of a sustainable feedback pattern that would be achieved by altering growth trends among the five variables under three scenarios. They noted that their projections for the values of the variables in each scenario were predictions "only in the most limited sense of the word", and were only indications of the system's behavioral tendencies.[10] Two of the scenarios saw "overshoot and collapse" of the global system by the mid- to latter-part of the 21st century, while a third scenario resulted in a "stabilized world".[11]:11 Exponential reserve index A key idea in The Limits to Growth is the notion 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. The static index is 775/1.85=418 years, but the rate of chromium consumption was growing at 2.6 percent annually, or exponentially.[1]:54–71 If instead of assuming a constant rate of usage, the assumption of a constant rate of growth of 2.6 percent annually is made, the resource will instead last The planet earth is a finite system, which means it has limited or finite resources In general, the formula for calculating the amount of time left for a resource with constant consumption growth is:[12] where: y = years left; r = 0.026, the continuous compounding growth rate (2.6%). s = R/C or static reserve. R = reserve; C = (annual) consumption. https://en.wikipedia.org/wiki/The_Limits_to_Growth 2/10 5/15/2018 The Limits to Growth - Wikipedia The authors list a number of similar exponential indices comparing current reserves to current reserves multiplied by a factor of five: Years Resource Consumption, Static index Exponential index 5x reserves annual growth rate exponential index Chromium 2.6% 420 95 154 Gold 4.1% 11 9 29 Iron 1.8% 240 93 173 Petroleum 3.9% 31 20 50 The static reserve numbers assume that the usage is constant, and the exponential reserve assumes that the growth rate is constant. The exponential index has 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.[13][14][15][16] 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. In Limits to Growth: The Thirty Year Update there are several pages explaining that new resources are found over time and that the current reserves therefore change but that ultimately resources are finite. (Earlier editions did explain this as well, but not in as much detail.) The standard model includes a resource base of double that of what they have calculated, but the book includes model runs where the assumed resources are infinite, but those model runs still result in overshoot and collapse from other factors. Conclusions After reviewing their computer simulations, the research team came to the following conclusions:[1]:23–24 1. Given business as usual, i.e., no changes to historical growth trends, the limits to growth on earth would become evident by 2072, leading to "sudden and uncontrollable decline in both population and industrial capacity". 2. Growth trends existing in 1972 could be altered so that sustainable ecological and economic stability could be achieved. 3. The sooner the world's people start striving for the second outcome above, the better the chance of achieving it. Criticism Criticism of LTG was immediate. Peter Passell and two co-authors published a 2 April 1972 article in the New York Times describing LTG as "...an empty and misleading work .... best summarized ... as a rediscovery of the oldest maxim of computer science: Garbage In, Garbage Out." Passell found the study's simulations to be simplistic, while assigning little value to the role of technological progress in solving the problems of resource depletion, pollution, and food production. They charged that all LTG simulations ended in collapse, predicted the imminent end of irreplaceable resources, and, finally, that the entire endeavor was motivated by a hidden agenda: to halt growth in its tracks.[17] In 1973, a group of researchers at the Science Policy Research Unit at the University of Sussex, published Models of Doom; A Critique of The Limits to Growth. The Sussex group examined the structure and assumptions of the MIT models. They concluded that the simulations were very sensitive to a few key assumptions and suggest that the MIT assumptions were unduly pessimistic. The Sussex scientists concluded that the MIT methodology, data, and projections were faulty and do https://en.wikipedia.org/wiki/The_Limits_to_Growth 3/10 5/15/2018 The Limits to Growth - Wikipedia not accurately reflect reality.[18] Claiming that the Sussex critics applied "micro reasoning to macro problems", the LTG team, in "A Response to Sussex", described and analyzed five major areas of disagreement between themselves and the Sussex authors.[19] The report has been criticized by academics, economists and businessmen.[20][21] Critics claimed that history proved the projections to be incorrect, which was specifically based on the popular belief that The Limits to Growth predicted resource depletion and associated economic collapse by the end of the 20th century.[22]:23 The Limits to Growth faced ridicule as early as the 1970s.[23][24] Attacks were made on the methodology, the computer, the conclusions, the rhetoric and the people behind the project.[25] Yale economist Henry C. Wallich agreed that growth could not continue indefinitely, but that a natural end to growth was preferable to intervention. Wallich stated that technology could solve all the problems the report was concerned about, but only if growth continued apace. By stopping growth too soon, Wallich warned, the world would be "consigning billions to permanent poverty".[25] Julian Simon, a professor at the Universities of Illinois and, later, Maryland, argued that the fundamental underlying concepts of the LTG scenarios were faulty, because the very idea of what constitutes a "resource" varies over time. For instance, wood was the primary shipbuilding resource until the 1800s, and there were concerns about prospective wood shortages from the 1500s on. But then boats began to be made of iron, later steel, and the shortage issue disappeared. Simon argued in his book The Ultimate Resource that human ingenuity creates new resources as required from the raw materials of the universe. For instance, copper will never "run out". History demonstrates that as it becomes scarcer its price will rise and more will be found, more will be recycled, new techniques will use less of it, and at some point a better substitute will be found for it altogether.[26] His book was revised and reissued in 1996 as The Ultimate Resource 2.[27] Robert Solow from MIT argued that prediction in The Limits to Growth was based on a weak foundation of data.