Light pollution: shared solutions for public and environmental health
April 2024
The ecological transition is one of the major concerns of the French people, and all the players, led by the government, agree that urban areas play a major role in its practical implementation, as close to the people as possible (energy renovation, development of renewable energies, transport, air quality, biodiversity, etc.).
Urban areas play a major role in affirming and achieving the objective of moving away from the current model of a linear economy towards a more sustainable circular economy, with sober and responsible consumption of resources. However, although they have wider powers in terms of ecological transition, urban areas do not yet have the financial resources to enable them to roll out structured policies on a large scale over the long term.
On 27 March 2024, as part of France urbaine’s Biodiversity Working Group and during a joint session with its Environmental Health Group, more than fifty elected representatives and technicians from major urban areas met to share their thoughts and practices in the fight against light pollution.
The many challenges of light pollution
According to a study carried out between 2012 and 2016, outdoor night-time light intensity has increased by an average of 2.2% per year worldwide.
In France, the law recognises the need to prevent, limit or eliminate artificial light emissions when they :
-
are likely to present a danger or cause excessive disturbance to people, fauna, flora or ecosystems,
-
cause a waste of energy,
-
or prevent observation of the night sky.
While the issue also encompasses notions of common good and tourism (85% of mainland France will be exposed to a sky degraded by light pollution in 2020, according to the French Office for Biodiversity), and the impact on the climate of greenhouse gas emissions linked to the energy consumption of lighting, participants’ discussions focused in particular on the consequences in terms of human and environmental health.
« One health »: significant effects on human and environmental health
Biodiversity is heavily impacted by light pollution, which contributes to its collapse, despite the fact that 28% of vertebrates and 65% of invertebrates are nocturnal (in whole or in part), and that 90% of plants are pollinated by insects that live mainly at night. Light pollution can therefore cause dazzle, disorientation, collisions and the fragmentation of night-time space for species repelled by light and those attracted by it (which can become agitated around it to the point of exhaustion). Over the last 30 years, almost 80% of the insect biomass has disappeared in Europe, mainly due to the intensification of farming practices and the use of pesticides, but billions of insects also die under our streetlights every year.
Human health is thus affected in two ways: indirectly, through the deterioration in the health of the ecosystems on which we depend and of which we are a part, and directly, as documented by a growing body of research into the health effects of exposure to artificial light and its composition. The human biological clock is largely disrupted, and the report on « light pollution » and « public health » by the French National Academy of Medicine recommends, for example, « including exposure to light at night in the list of endocrine disrupting agents ».
Solutions to be deployed: rethinking public lighting and raising awareness
The question of the levers available to local authorities was a key topic of discussion. With a view to setting an example, action on public lighting was recognised as essential by the participants, whose local authorities have already made considerable progress on these issues as part of their energy efficiency plans.
While it is often a question of lighting less, with partial or total extinction of public lighting as the first flagship action, particularly in areas with high ecological challenges, it is essential to light better. This requires work on orientation (towards the ground), colour temperature (avoid blue light), lighting period and intensity. Private lighting, which can be a more or less significant source of light pollution depending on the area, is also an area that needs to be addressed. To get all the local players on board, it is vital to carry out strong communication and awareness-raising initiatives (information media for retailers, night-time events for the general public, etc.) to help people better understand the issues and the regulations.
Green and blue… and black: the commitment of the Nice Côte d’Azur metropolitan area
The Nice metropolitan area, which took part in the discussions, explained its approach, as its green and blue framework, currently under review, will soon include a ‘black framework’ to combat the fragmentation of nocturnal species. One of the major steps in the local initiative has been to draw up an inventory of ecological corridors, identifying the main sources of light pollution and areas with high ecological value. The cross-disciplinary work carried out by the city’s public lighting and biodiversity departments was presented as a key element in an approach that was politically expressed in a metropolitan deliberation in 2018 »to reduce the impact of light pollution on biodiversity« . The metropolis is committed to differentiated management of public lighting according to the needs and challenges of the local authorities, which it actively supports. Of the 51 local authorities, 34 are involved at various levels.
The local authority stresses the importance of working with the police (around surveillance cameras, for example) to ensure that safety issues are not impacted. While a number of positive feedbacks seem to show that there is no increase in crime and road accidents, and that there are even fewer without public lighting, the feeling of safety among residents remains an essential issue to be explored, particularly when it comes to lighting in town centres and suburban areas.