This article analyses a corpus of science fiction and climate fiction (project PARVIS, I-SITE FUTURE) from the point of view of lexical creation and its contribution to cognitive estrangement. The latter is a feature of these literatures, where the creation of imaginary worlds, whether dystopian or not, leads authors to create the neologisms needed to designate the new elements of the worlds they deploy (technological objects and human, animal or plant creatures, pathogenic microbes and diseases, organisations and social groups, etc.) as well as the actions and states associated with these elements. The notion of estrangement is first clarified before the corpus is described. Neologisms constitute lexical triggers of estrangement; they are identified using morpho-syntactic patterns based on the concepts and lexicogenic matrices introduced by Sablayrolles (La néologie en français contemporain. In: Examen du concept et analyse de productions néologiques récentes. Honoré Champion, 2000) and implemented in the software suite Unitex/GramLab. A textometric analysis enables to analyse the contribution of these lexical innovations to estrangement in a contrastive manner between the novels from the corpus PARVIS and a French newspaper.