Green roofs for sustainable urban development : the Oslo case study

Abstract

Rapidly growing cities around the world face complex issues in sustainable urban development. In particular, urban ecological systems and food security are important in ensuring healthy, sustainable cities but they are threatened by population growth. Green roofs are a tool that is increasingly used in urban development due to their ability to control stormwater runoff and lessen the likelihood of flooding and combined sewer system overflow. However, this narrow focus on stormwater limits the ability to use diversely and benefit from their multi-perspective values and causes a scaling-up of green roof development rather than out, so that green roofs have less opportunities to contribute to sustainable urban development and ultimately global sustainability. Therefore, the objective of this research is to explore what is needed for a city to make green roofs more widely and effectively used in sustainable urban development.

In order to accomplish this objective, a case study was conducted in Oslo, Norway to explore the human and non-human actors, opinions among stakeholders about local green roof development, and the challenges and opportunities present for achieving an ideal future situation. This research was done within the theoretical frameworks of systems thinking and agroecology, which aim to achieve a holistic comprehension of the problem situation by exploring not only the smaller subsystems and processes but also the overall whole system. Qualitative research methods were used to collect data through participant observations, semi-structured interviews, a focus group, a survey, and through primary and secondary documents. Results were analyzed through a stakeholder analysis and a multi-system evaluation. Green roof development requires interdisciplinary cooperation between stakeholders and needs significant advances in research, demonstration, and financial valuation in order to achieve widespread diffusion and optimally realize the values of ecology, economy, and society.