Nocturnal illumination is both a hallmark and a driving force of global urbanisation—and increasingly an urgent environmental concern. From satellite images of the Earth glowing at night, we glimpse how Homo urbanus has shaped a luminous Anthropocene. Far from being a neutral backdrop, however, light infrastructures and nocturnal illumination actively produce urban space. They stretch the frontiers of economic and social life beyond daylight hours, enabling the expansion of urban networks and infrastructures.

Yet, despite growing scientific insight and more robust legal frameworks, regulating nocturnal lighting remains challenging. Competing economic interests, rapid technological change, and persistent social inequalities continue to shape how, and for whom, cities are lit. This uneven illumination reveals the infrastructural politics embedded in light masterplanning and raises critical questions about sustainability, justice, and the future of urban nights.

An ecological challenge

Public lighting became an ecologically significant phenomenon in the nineteenth century with the spread of gas lighting networks, and its importance intensified with electrification at the turn of the twentieth century. Since the early twenty-first century, nocturnal illumination has accelerated rapidly. This shift coincides with the formalisation of public lighting as a tool of city marketing, safety provision, and post-industrial urban renewal, as well as with the widespread adoption of LED technology. Although LEDs were initially introduced to save energy, their high efficiency in producing visible light has led to an overall increase in light use, resulting in rising light emissions rather than their reduction. Combined with the extensive pace of urban renewal in Swiss cities, this has resulted in a rapid rise in light emissions in Switzerland, which, according to the Federal Offices for the Environment, has doubled over the past 25 years.

Although the ecological impacts of artificial lighting were recognised as early as 1937—in a study by William Rowan showing premature gonadal development in London starlings exposed to nocturnal illumination—scientific research has expanded significantly over the past 15 years. This body of research confirms that excessive illumination acts as social and endocrine disruptor.

From the celebration as spectacle to a more critical discussion

In Switzerland, aesthetic and cultural concerns about public lighting led to the first guidelines and regulations as early as the mid-twentieth century. Nevertheless, it remains challenging to control nocturnal illumination due to its inherently fragmentary nature in urban space. At the same time, there is a gradual change in public discourse and media representation of nocturnal illumination, from its celebration as spectacle to a more critical discussion of its socio-ecological consequences.

While nocturnal illumination has long been treated primarily as a techno-scientific issue, it is gradually being recognised as a socio-technical and political one. Public associations and initiatives such as Raum für Alle, DarkSky Switzerland, SWILD, and SZ have drawn attention to the uneven effects of artificial lighting on social accessibility as well as on plants and animals. Although this politicisation is still in its early stages, it has already stimulated debates on reconciling accessibility, justice, and the necessity of dark corridors, and the protection of nocturnal habitats.

Yet a deeper issue lies in the treatment of the nighttime as an economic frontier. A wide range of actors shape nocturnal illumination—not only public electricity utilities and infrastructure providers such as SBB, Zurich Public Transport, and the Federal Roads Office, but also numerous private actors who promote the night-time economy or signal power and presence through advertising and targeted lighting.

Light pollution is unevenly distributed

What has largely remained overlooked is the need for a political-ecological perspective on the unequal impacts of artificial lighting on human populations. Unlike animals and plants, people’s residential locations are shaped by housing markets, affordability, and access. Housing near brightly lit infrastructures—such as stadiums or transport corridors—is often cheaper, while proximity to darker, greener areas tends to be more expensive, at least in urban contexts. As a result, exposure to light pollution is unevenly distributed.

As public lighting infrastructures are transformed through digitalisation and energy transitions, it is therefore crucial to foreground questions of socio-ecological justice. Without careful attention, these transformations risk unintentionally reproducing—or even intensifying—existing inequalities in access, health, and environmental quality.

This is the slightly adapted version of an article that first appeared in German. Eine politisch-ökologische Perspektive auf Lichtlandschaften Hotspot: Zeitschrift des Forums Biodiversität Research project Spotlight: Sustainability Potential of Outdoor Light Technology, based at the University of Zurich

Nitin Bathla, Norman Backhaus, Sophia Heller, Space, Nature and Society