In their endeavours to increase the climate resilience of cities, urban administrators, planners and decision makers have to deal with considerable uncertainty and complexity. The effects of climate change in terms of the impact of extreme weather events and the frequencies and intensities with which they occur are uncertain. Consequences in terms of associated risks to cities, for their infrastructures and inhabitants, depend very much on preparations that cities have in place or are planning for, to cope with these phenomena. Moreover, uncertainties arise from cascading effect, due to (un)foreseen relations between different urban areas, stakeholders or adaptation measures.
Despite these considerable uncertainties, decision makers have to act. Although the terms uncertainty, risk management and complexity are widely used in the policy making domain, there is little appreciation for the fact that there are many different dimensions of uncertainty, and there is a lack of understanding about their different characteristics, relative magnitudes, and available means of dealing with them. This results in cities experiencing difficulties in how to deal with uncertainty and complexity, which nevertheless must be acknowledged and integrated into
policy making for the future.
RESIN has produced a document that aims to break down complexity and uncertainty into understandable definitions and aspects in the context of urban climate resilience. This improves the ability of linking methods and instruments to deal with complexity and uncertainty with the particular challenges that arise. Climate change policies in general are very reliant on uncertainty management. This means that the choice of
risk and uncertainty management strategy should be carefully weighed against the particular “uncertainty or complexity challenge” that is at stake. This effort should be seen as the starting point of addressing the issues of uncertainty and complexity in the RESIN project. It provides city planners in general with an overview of methods and tools they can use to handle complexity and uncertainty. The methods and instruments presented in this report will be selectively discussed and applied within the RESIN cities.