We should comment that most of these self-sufficiency books start out with a preface that we will paraphrase as "humanity is running out of energy and resources; thus, we must change our evil high technology ways and go back to basic living off the land." These statements should not be taken at face value, because many of them are not supported by scientific evidence. For example, books written in the late seventies, during the energy crisis, predict that energy costs would only get worse - when in fact they got (and have remained) much better.