The future is uncertain and exploring uncertainties is one of the most diffi cult of all the planning processes. Planners and forecasters have become so bound up in a modern sense of linear time that the future is too often described as stretching from the present in a relatively consistent line of upward progress or downward failure. That is, the future is described as a line from the present based on trends that stretch directly from the past. This belief, partly a self-confi rming one, is true enough (and therefore wrong enough) to be completely misleading. Metrics-based trajectories from the past to the present are only one indication of possible futures.