In Searching for a Miracle: ‘Net Energy’ Limits and the Fate of Industrial Society, Richard Heinberg examines 18 energy sources by their “net energy” and nine other criteria. Published jointly by Post Carbon Institute and International Forum on Globalization, the report is intended as a non-technical examination of a basic question: Can any combination of known energy sources successfully supply society’s energy needs at least up to the year 2100? In the end, we are left with the disturbing conclusion that all known energy sources are subject to strict limits of one kind or another. Perhaps the most significant limit to future energy supplies is the “net energy” factor—the requirement that energy systems yield more energy than is invested in their construction and operation.
The report explores some of the presently proposed energy transition scenarios, showing why, up to this time, most are overly optimistic, as they do not address all of the relevant limiting factors to the expansion of alternative energy sources. Finally, it shows why energy conservation (using less energy, and also less resource materials) combined with humane, gradual population decline must become primary strategies for achieving sustainability.