Risks in urban rooftop agriculture: Assessing stakeholders' perceptions to ensure efficient policymaking

Rooftop agriculture (RA) is an innovative form of urban agriculture that takes advantage of unused urban spaces while promoting local food production. However, the implementation of RA projects is limited due to stakeholders' perceived risks. Such risks should be addressed and minimized in policymaking processes to ensure the sustainable deployment of RA initiatives. This paper evaluates the risks that stakeholders perceive in RA and compares these perceptions with the currently available knowledge, including scientific literature, practices and market trends. Qualitative interviews with 56 stakeholders from Berlin and Barcelona were analyzed for this purpose. The results show that perceived risks can be grouped into five main categories: i) risks associated with urban integration (e.g., conflicts with images of "agriculture"), ii) risks associated with the production system (e.g., gentrification potential), iii) risks associated with food products (e.g., soil-less growing techniques are "unnatural"), iv) environmental risks (e.g., limited organic certification) and v) economic risks (e.g., competition with other rooftop uses). These risks are primarily related to a lack of (scientific) knowledge, insufficient communication and non integrative policymaking. We offer recommendations for efficient project design and policymaking processes. In particular, demonstration and dissemination activities as well as participatory policy making can narrow the communication gap between RA developers and citizens. (C) 2016 Elsevier Ltd. All rights reserved.