This finding is explained by the fact that humanity can see relatively simple ways to overcome potential shortages without assuming dramatic discoveries or technological breakthroughs. On the supply side, substitutes, recycling, and the mining of lower-grade ores would occur on a significantly increased scale if the price were to rise somewhat. On the demand side, a similar rise would induce the use of substitutes, economies in use, institutional reorganization, and changes in tastes that would help close the gap.
The authors use World III model to calculate population growth rates and resource scarcity. This is a simulation models which allows scientists to evaluate the variables and their interactions. The authors criticize modern growth theories and prove that there is not direct correlation between increasing resource use and the amount of reserves needed in future. The book proposes new formulas for calculating 'the time left for a resource". The authors (Meadows et al 1972) conclude that: It is possible to alter these growth trends The state of global equilibrium could be designed so that the basic material needs of each person on earth are satisfied and each person has an equal opportunity to realize his individual human potential" (6). The presence of social costs arising from population growth suggests that society should at least reduce resource usage.
The social and institutional costs of population growth may take four forms. The first involves a more contrived and regulated way of life, resulting from the need to ration increasingly scarce common property resources, such as public land, air, and water. Projections of water demands and supplies, for example, indicate that at current resources more and more regions will be threatened with shortages. This does not mean that catastrophe looms ahead. "Man possesses, for a small moment in his history, the most powerful combination of knowledge, tools, and resources the world has ever known" (Meadows et al 45). There are many ways to alleviate these shortages, including building additional storage facilities, enacting more stringent regulation of waste emissions, increasing charges to reduce consumption, transferring population and economic activities to other regions, and constructing longer and larger canals to import water from surplus regions.
I agree with the authors that when shortages threaten, prices rise, inducing increased supplies and choking off demand. But this way of posing the question is convenient shorthand that captures the concern that many feel about the long-run consequences of population growth. Predictions with respect to the population and economic growth assumptions are that the world is unlikely to experience any serious shortages during the next 30 to 50 years. "The alternative is to wait until the price of technology becomes more than society can pay, or until the side-effects of technology suppress growth themselves, or until problems arise that have no technical solutions" (Meadows et al 35). Factors other than population and economic growth may arise and threaten population with serious shortages. But strictly as a consequence of population and economic growth in the world is likely to be able to find the necessary resources to meet rising demands without price rises of such a magnitude that the general