Minimising light pollution by discouraging nighttime lighting in businesses

This project was conducted in 2021/2023 as part of our framework agreement with the Direction Interministérielle de la Transformation Publique (DITP). We assisted the DITP behavioural sciences department following a solicitation from the their office on biodiversity.

In 2021, the Office français de la biodiversité (OFB) estimated that 85% of the metropolitan territory was exposed to high levels of light pollution, primarily generated by artificial nighttime lighting. Light pollution has numerous consequences on biodiversity, disrupting natural habitats and life cycles of species by affecting reproduction, foraging, and migration.

Despite the obligation since 2013 for businesses to turn off certain nighttime lights such as shopfronts, offices, and signs, nighttime lighting practices tend to persist in the commercial sector.

To better understand the behavioural (psychological, motivational, decision-making) and structural barriers to nighttime extinction of commercial lights, we conducted field research during which we interviewed representatives from local authorities, experts, and merchants in Paris, La Souterraine (Creuse), and in Lyon. In particular, we observed the nighttime lighting of more than 200 shops and conducted interviews with more than 80 shopkeepers. 

There are a number of obstacles to compliance with nighttime lighting regulations: 

• Lack of awareness that rules exist 
• Complexity of the rules, which vary according to the type of lighting, the types of premises and the times at which they must be switched off, depending on usage. 
• Some retailers feel that nighttime lighting contributes to the visibility and image of their business, and that it therefore has commercial and strategic implications. 
• For some, nighttime lighting provides reassurance in the face of concerns about incivility and theft that could affect their businesses at night. 

Faced with these difficulties, and with a view to devising appropriate solutions to change retailers’ practices, we have identified a number of promising solutions: 

• Firstly, simplification of the regulations to make it easier for local authorities to take charge of and apply them, and for the retailers concerned to understand them;
• Communication: many retailers are unaware of the regulations in force, and local authorities themselves sometimes seem reluctant to broach the subject with retailers in their area; and
• Work with retailers to make the changeover as easy as possible: through personalised feedback, dedicated tools and support. 
• Relying on the need for recognition and the positive reputation of retailers (particularly as ‘green’ players) to promote change.

We compiled these ideas, alongside some methodological guidance, in a toolkit for practitioners who wish to tackle the issue of nighttime lighting in shops. 

Download the report on the DITP website.