Mineral Resources and The Limits to Growth

In writing an editorial for this issue on mineral resources, I was immediately reminded of The Limits to Growth (Meadows et al. 1972), a book that I read avidly from cover to cover as a young postdoc. For anybody interested in humanity’s effect on the environment and its nearterm consequences, it is still a fascinating read. The authors summarised a computer model of the likely effects of sustained economic growth on the Earth and the human population. Based on historical data from 1900 to 1970, they observed exponential growth in total human population, resource consumption, food consumption, industrialisation and environmental pollution. They fitted exponential growth curves to the data and assumed in their “standard model” that there was a 250year supply of all resources at 1970 rates of consumption. They then developed what they considered to be appropriate feedback loops between the different parameters, such as between resource consumption and rate of industrialisation, food consumption and available arable land, gross national product (GNP) per capita, and birth rate. These feedback loops were added to the model, which was constructed to project how the global system would develop out to the year 2100. The results were startling.