This report for the City of Hamburg highlights that climate change adaptation is a dynamic process with many uncertainties. A core message for public sector institutions is to "bear climate adaptation in mind," especially through the integration of climate change concerns in upcoming decisions and the implementation of measures that have co-benefits today. Furthermore, adaptation activities should begin today if the costs of adaptation potentially remain constant over time or tend to rise. The case studies investigated also indicate that the evaluation of measures must take into account local conditions.

Jenny Tröltzsch and Max Grünig presented the project results together with the project partner Hamburgische WeltWirtschaftsInstitut (HWWI) in Hamburg.The final presentation showed that still large knowledge gaps on the costs of climate change and the costs and benefits of adaptation measures exist. The cost-benefit analyses of adaptation measures in Hamburg show a large bandwidths for local case studies. But nevertheless the results suggest that higher benefits than costs exist for several adaptation measures, for example a green roof program. Furthermore, it is important to initiate adaptation activities of private actors, to reduce damages, e.g. from heavy rain events.