Climate change adaptation with green roofs: Instrument choice and facilitating factors in urban areas

Abstract

ABSTRACT Although green roofs are considered as a no-regret adaptation measure that helps to address various impacts of climate change, they are still rather rare. This paper explores three major European cities that have policies in place that are supposed to facilitate the installation of green roofs. We ask what approaches were chosen by local authorities to promote green roofs and which factors facilitated their implementation. Our analysis is based on implementation literature in general as well as adaptation policy literature in particular. It combines literature reviews and eleven interviews with policymakers and other stakeholders. The study reveals that immediate threats and particular events (e.g., urban heat islands or floods), an overall social and political environment favoring green solutions, so-called change agents, and a supportive framing determine if green roofs are considered as an attractive solution. However, even when multiple benefits of green roofs are beyond doubt, local governments largely prefer fiscal incentives over mandatory policies.