French wildlife prospers from darker streets – but debate over public safety remains

Reduced artificial street lighting is helping nocturnal wildlife recover in parts of France, even as cities continue to rethink how safe dark streets feel for residents. 

Satellite data published in Nature and based on VIIRS observations between 2014 and 2022 show global light pollution rising by around 16 percent. Europe, however, is moving in the opposite direction, with an estimated 4 percent decline in night-time light emissions.

Researchers say France is a key contributor to that shift, with some areas recording reductions of some 33 percent, largely linked to post-energy-crisis policies that reduced or restructured street lighting in many areas after 2022.

Ecosystems benefit from dark

Ecologists have long warned that artificial lighting is a significant driver of ecological disruption.

The Agence de la transition écologique says that night-time lighting disrupts the behaviour of many nocturnal species by altering their feeding, movement and reproduction patterns. It also contributes to the fragmentation of habitats by breaking up dark corridors used for movement and navigation.

Species particularly affected include bats, hedgehogs, moths and glow-worms, while broader changes in light cycles can also disturb animals active during the day that depend on predictable night-time darkness for rest.

The satellite analysis suggests that where lighting has decreased ecological pressure from artificial illumination may also be easing. While it does not directly measure biodiversity outcomes, researchers describe the reduction in night-time brightness as a potentially meaningful shift for ecosystems under sustained light stress.

“Where we see reductions in lighting, we are likely also seeing reduced ecological disturbance, even if the biological response takes time to appear,” the authors write, based on their analysis of VIIRS satellite data.

Safety concerns and policy reversals

While supporters of reduced lighting champion the reduced energy use and ecological benefits, critics say that darker streets can heighten perceptions of insecurity, particularly for people walking late at night or returning from work.

This debate was reflected in the recent municipal elections, when many newly elected mayors opted to turn the lights back on. 

“In Bordeaux, it (our strategy) enables 90 percent of night-time journeys to be made in lit areas,” said mayor Pierre Hurmic, who has adopted a targeted approach in which selected streets remain lit while others are dimmed or switched off.

The satellite data highlight a more uneven reality: while global light pollution continues to rise, Europe is recording a net decline, and France is among the countries where overnight lighting policies have had a measurable impact on reducing night-time brightness.

In practical terms, that means darker skies for some regions, alongside a growing patchwork of local approaches: full-night lighting restored in some towns, targeted dimming in others, and continued reductions where energy savings and ecological goals remain prioritised.

Has the public lighting blackout affected you or do you not mind the streets being dark? Let us know at letters@connexionfrance.com