Green roofs: A possible best management practice for enhancing the environmental quality of Ghanaian cities

Abstract

City expansion typically erodes the natural ability of the locale to perform its ecosystem services. This paper discusses green roofs and their potential benefits for Ghanaian cities in terms of improving environmental quality. Limited analysis shows that daily minimum temperatures of cities like Accra are rising faster than the daily maximum thereby decreasing the comfort index of city dwellers. Electricity consumption is increasing amid challenges in supply while the frequency of flooding after rainstorms is also on the rise. Green roofs have demonstrated reduction of these issues in several parts of the world and could help minimize the magnitudes of these issues in Ghanaian cities if adopted as an urban best management practice. Since this technology is new to Ghana with no local research, this paper also discusses the potential economic gains and associated research opportunities as well as some strategies to consider if the green roof technology is to be pursued. Successful introduction and implementation of green roofs in Ghana will depend on awareness creation, research and development of growing substrate, plant species and other structural components, formulation of guidelines for the industry, government support through legislation and provision of incentives to promote its adoption. We hope this paper will initiate discussion between various stakeholders in sustainable city development in Ghana in this era of climate change and variability.

Key words: Green roof, urban, environmental quality, best management practice, ecosystem services.