A technical appraisal of the IIASA energy scenarios

Several shortcomings in a major study of the world's energy system are described. The study, entitled Energy in a Finite World, resulted in widely publicized conclusions and urgent policy recommendations that were derived from detailed projections of the global energy future. A set of computer models was used to produce these projections, which are analyzed here in two ways. First, treating the models as a black box, it is shown that several principal results are effectively prescribed informally in input data that pass through the models unchanged. Second, despite claims of robustness, detailed sensitivity analysis shows that the energy supply projections are highly sensitive to perturbations in various input data. Early work that revealed this problem is not cited, and standard sensitivity tests are not provided in the study. Thus, despite the appearance of analytical rigor, the study's conclusions are evidently based on opinions rather than objective robust analysis.Bill Keepin is Research Fellow at the Beijer Institute, Royal Swedish Academy of Sciences, Box 50005, S-104 05 Stockholm, Sweden. This work was carried out at IIASA, where he was Research Scholar from October 1981 to June 1984.