(O)ver the last three decades, under pressure of concern about global change, studies about possible futures of social and ecological systems have rapidly developed. Some of them have reached an impressive level of ambition and impact on policy debates. However, only a limited number of research fields have yet embarked on such studies, whereas many more should become involved. Development of such research is also limited by the fact that it is still considered almost exclusively as a matter of collective assessment, at the interface between academia and policy making, rather as the fundamental scientific endeavour it is really. To push further, a number of stumbling blocks have still to be overcome until the conjectural nature of any research about future events and processes is fully accepted and scientists widen their repertoire of approaches for the study of possible futures. Such a study is necessary to prepare both for long-term transformations of the environment and for extreme events: beyond some significant differences, both domains share the fundamental traits that make the study of futures such a peculiar and challenging endeavour. In this effort, the resources provided by the futures studies field could be more thoroughly mobilized. To cite this article: L Mermet, C R. Geoscience 340 (2008). (C) 2008 Academie des sciences. Published by Elsevier Masson SAS. All rights reserved.