"Within a period of time which is very short compared with the total span of human history, supplies of fossil fuels will almost certainly be exhausted. The loss will make man completely dependent on water power, atomic energy and solar energy ... for driving his machines. There are no fundamental physical laws that prevent such a transition and it is quite possible that society will be able to make the change smoothly. But it is a transition that only happen once in lifetime of the human race. We are quickly approaching the point where, if machine civilization should, because of some catastrophe, stop functioning, it will probably never again come into existence."
Harrison Brown "The Challenge of Man's Future" Viking, 1954
Um grande senhor, este geoquímico Harrison Brown!