When US federal and state governments began to require environmental impact studies and technology assessments for new projects in the early 1970s, Futures Studies (FS) was the methodology of choice. Within a few years, though, criticisms of the impact assessments (IA) abounded and much of IA was considered ineffective. During the same period, science fiction (SF) was increasingly popular as a way to explore possibilities. A comparison of the two approaches shows significant similarity, with SF emphasizing human concerns and language while IAs focus on quantitative technical approaches and language. A series of t-tests resulted in no significant difference in statements of impacts in 51% of the 67 standard categories of IA between SF works that fit IA constraints and IA reports focused on the same technologies, and eight categories in which the SF had significantly more statements describing potential impacts than equivalent IAs. For the specific case of nuclear power, SF stories were more effective at predicting harmful events. These results suggest a new subgenre: SF works which fit IA constraints, called here Extrapolative Fiction (EF). Such works are recommended to be included in the IA process with suggestions for ways to do so.