Mainstreaming ecosystem-based adaptation: transformation toward sustainability in urban governance and planning

The concept of ecosystem-based adaptation is advocated at international, national, and regional levels. The concept is thought to foster sustainability transitions and is receiving increasing interest from academic and governmental bodies alike. However, there is little theory regarding the pathways for its systematic implementation. It furthermore remains unclear to what degree the concept is already applied in urban planning practice, how it is integrated into existing planning structures and processes, and what drivers exist for further integration. Against this background, this study examines potential ways to sustainably mainstream ecosystem-based adaptation into urban planning. Eight municipalities in Southern Germany were investigated to analyze the processes of mainstreaming ecosystem-based adaptation into current planning practice. Although the mainstreaming entry points for ecosystem-based adaptation were identified to be appreciably different, the results of the study show how mainstreaming has generally led to patterns of change in: (1) on-the-ground measures, (2) organizational structures and assets, (3) formal and informal policies and instruments, (4) external cooperation and networking, and (5) the general working language. In all these areas, ecosystem-based adaptation to heat and flood risk is highly compartmentalized. Furthermore, although scholars have drawn attention to the risk of "mainstreaming overload," the results suggest that at the local level, the integration of ecosystem-based adaptation is strongly driven by departments' experience in mainstreaming other cross-cutting issues, namely environmental planning, climate change mitigation, and disaster risk management. Based on the findings, ways to leverage sustainability transitions via mainstreaming are discussed. It is concluded that systematic mainstreaming is a promising avenue for initiating and promoting local transitions and transformative adaptation. The study demonstrates the applicability of the presented mainstreaming framework for assessing and driving the mainstreaming capacity of local governments, thus also addressing the lack of related indicators highlighted in the Fifth Assessment Report of the United Nations Intergovernmental Panel on Climate Change (IPCC)