The Limits to GrowthOne of the most influential books on the subject of resource efficiency in the 20th Century was The Limits to Growth [ meadows1972limits  ] by Donella H. Meadows, Dennis L. Meadows, Jørgen Randers, and William W. Behrens III.  Commissioned in 1972 by the Club of Rome, an influential think-tank, the study used computer systems – an innovation at the time – to model the interaction of population, pollution, capital investment, agriculture and natural resources. Each of these drivers had positive and negative feedbacks with each other – e.g. as agriculture improved so did food per capita which boosted population, at the same time as population increased so too did pollution and natural resource consumption, while a decline in resources decreased industrial output.