I am posting this from The Oil Drum because of the very interesting commentaries included after their articles. People who follow this website are generally highly trained people in the various scientific disciplines.
In Heinberg's forward to the study conducted by The Post Carbon Institute, and based on that study, is critical of the optimistic projections of the Energy Information Administration (EIA). Keep in mind that the EIA is a US government environmental agency which, of course, is stacked with people who have a stake in the capitalist economy that requires never-ending growth. He explains how this pro-capitalist bias works to influence the wider society.
...if this report [The Post Carbon Institute's study] is right, then how could mainstream energy analysts have gotten so much so wrong? ...it is fairly easy to trace the convergence of interests among major players. First, the shale gas industry was motivated to hype production prospects in order to attract large amounts of needed investment capital; it did this by drilling the best sites first and extrapolating initial robust results to apply to more problematic prospective regions. The energy policy establishment, desperate to identify a new energy source to support future economic growth, accepted the industry’s hype uncritically. This in turn led Wall Street Journal, Time Magazine, 60 Minutes, and many other media outlets to proclaim that shale gas would transform the energy world. Finally, several prominent environmental organizations, looking for a way to lobby for lower carbon emissions without calling for energy cutbacks, embraced shale gas as a necessary “bridge fuel” toward a renewable energy future. Each group saw in shale gas what it wanted and needed. The stuff seemed too good to be true—and indeed it was.