This study revisits global energy projections made in 1981 using a model of the world economy, compares the consumption projections of the three fossil fuels-coal, natural gas and oil-with the observed data for the year 2000, quantifies the differences, and finally, attempts to attribute the differences between the projected and observed data to differences in the principal determinants of energy demand. The presentation and analysis of the data yield two valuable by-products: first, the data provide a detailed description of the changing patterns of global fossil fuel consumption over a relatively long interval of time. Second, in light of the experiences reported in this paper, it offers some guidance to those charged with the highly speculative task of projecting the demand for one of the most important components of material well being 20-30 years into the future. This is especially relevant given the current concerns for energy-supply security and alobal climate change. (C) 2007 Elsevier Ltd. All rights reserved.