Light in urban parks: balancing humans’ needs, nature’s health, and sustainability goals.

The growth of global population, coupled with increasingly dense urbanisation, presents a significant challenge to environmental sustainability and human well-being. Air and water contamination, noise and light pollution rise as urban centres expand to accommodate a growing populace. Moreover, being accustomed to living indoors for almost the whole day, people lose connection with nature, consequently suffering from increased levels of stress and depression, reduced immune defences, and loss of creativity and cognitive abilities. Nature-Based Solutions are a promising approach in response to these pressing problems and are currently implemented at various scales within a city, from the micro-level of individual buildings (e.g., green roofs and walls) to the macro-level of urban landscapes (e.g., urban parks). In particular, urban parks create pleasant views in contrast to drab concrete and brick surfaces, sequester carbon, and reduce the urban heat island effect, contributing to climate change adaptation and mitigation [1]. Green areas in cities also enhance biodiversity and provide spaces for recreation and social cohesion, contributing to reconstituting the crucial human-nature connection. In this context, light is fundamental. It shapes the appearance of urban parks during nighttime, making the space visible and driving its use after sunset; it helps in guaranteeing public security; it affects people’s perception, influencing their psychological state. However, it can also have negative impacts, generally referred to as light pollution. The goal of this contribution is to highlight benefits of good lighting in urban parks, and possible negative impacts due to poor design. The analysis is performed by discussing the results of previous relevant studies, finally driving simple design suggestions.