Complexity and uncertainty: implications for urban planning

Uncertainty is the core feature of complexity. In the present chapter, we will focus on those forms of uncertainty usually encountered in the assessment of, and intervention in, complex urban systems. After some pioneering contributions in the 1980s and 1990s, the issue of uncertainty has recently gained new traction in urban studies and the planning literature, but, in our opinion, not always in the substantial manner that it requires. There are still difficulties in fully acknowledging the disruptive implications of uncertainty and going beyond a mere and generic “adaptive” planning approach in response to it. Recognizing this challenge, this chapter focuses on how planning can cope with different forms of uncertainty by first of all taking seriously the differences between different decision situations.