Rethinking Sustainable Cities at Night: Paradigm Shifts in Urban Design and City Lighting

Since the establishment of the 17 Sustainable Development Goals (SDGs) by the United Nations General Assembly in 2015, various perspectives on sustainable cities have been developed and adopted in order to achieve a better and more sustainable future. However, background research has revealed that these goals and targets are limited because they do not take into account the growing body of lighting-related research in diverse fields on the impact of outdoor illumination on humans, flora and fauna. Recently, exterior lighting has been also linked to environmental degradation and as an indirect contributor to the current climate change emergency. Therefore, this study aims, by using online interviews with over 50 experts who work in the field of artificial light at night (ALAN), to assess whether the SDG objectives adequately reflect the latest knowledge about sustainable cities. The Elsevier 2021 SDG mapping matrix was used to find the correlation between the keywords that define each SDG and the keywords used by a group of international experts. This work suggests there are missing targets in current SDGs, especially SDG 11, connected to sustainable cities and communities. It also offers useful guidance on how to rethink the existing approach of cities that aim for sustainability, by applying eight (8) key aspects of urban lighting for healthier and environmentally responsible outdoor illumination, by means of a correct design process, along with a five-step strategic plan of action. The crucial role of multidisciplinary and interdisciplinary collaboration with experts has also been outlined, via the inclusion of new actors such as lighting professionals and researchers, who are currently absent in this important discourse.