Abstract :
[en] Since several years now, major metropolises around the world have inaugurated a new season of investigation about their future and visioning. What characterizes and unites these efforts is the long span horizon adopted –2030, 2050, 2100– the centrality of the environmental crises and the trust in the possibility to imagine visions and scenarios for agglomerations of several million inhabitants, characterized by hybrid and vast territories in which built and open spaces are strongly intertwined. What emerges from these efforts is a limited set of questions and their commonality. The emergence of a novel urban condition at planetary level and of a 'New Urban Question' described in terms of a growing divarication between rich and poor, increasingly insidious environmental crises and the crises of mobility have been reported on multiple occasions and frames today what we call the 'urban and ecological transition'. These efforts, while highlighting the extreme variety of metropolitan spaces requiring tailor-made strategies, open up a fructuous debate on possible comparisons and lay the foundations for a wide reflection on the necessary re-articulation of the urban and territorial project. In this frame, the research project carried out with the Habitat Research Centre (EPFL) for the construction of a vision (2050) for the Greater Geneva territory, while highlighting the controvertiality of the 2050 framework and the urgency of implementing rapid, radical and at times visionary actions to avoid forthcoming climatic tipping points, allowed the team to explore the role that –within this challenge– could be played by SOIL. If conceptualised as a four-dimensional, living body, driven by multiple, vital functions and fully interacting with other living entities, soil can –in fact– constitute a territorial keystone, able not only to rearticulate the urban and territorial project but also to trigger and vehiculate the process of transition.
