Alanex

Concept

Artificial light at night has been identified as a primary driver of environmental change in the 21st century and one of the main causes of the decline of many insects. Nocturnal insects are attracted to artificial light sources and circle them until they become easy prey for predators or die of exhaustion. Nighttime light also acts as a barrier, disrupting the spatial connectivity of insect populations. These local changes propagate across multiple levels – from the physiology of individual insects to species communities and and ecosystem services.

Project Description

The ALANex Project brings together lighting engineers, practitioners, and the ecological and social sciences to develop lighting transformation pathways that mitigate the negative impacts of artificial light at night, while also ensuring human lighting needs are met.

Key Findings

Ecological impact analyses of commercial broadband LEDs (2200 K, 2700 K, 4000 K) show that:

  1. The shape of the luminaire can reduce the number of attracted arthropods by up to 60% if the light beam is directed well from top to bottom.
  2. Dimming the light intensity by 50% can reduce the number of arthropods attracted to the light by up to 25%, while the color of the light is probably less important for both, flying and ground-dwelling arthropods.

  3. Public streetlights are universally used to improve visibility after dark and improve residents’ safety. In an experiment with 77 participants we examined the impact of exposure to LED streetlights of 2700K, 4000K and 6500K on the impression of light, the feeling of safety, and the well-being (affect, self-reported stress and physiological stress) in a small Swiss town with controlled light settings. Participants found warm light more pleasant, but cool white light reduced their stress levels more effectively.There is no such thing as the perfect street lighting; compromises are necessary. When planning new street lighting, energy savings and the protection of biodiversity should be taken into account alongside public acceptance.

  4. In a Swiss-wide stratified survey on anthropogenic light at night (ALAN) we found that satisfaction with light levels was high, that negative impacts of ALAN were recognized by most and that support for technological mitigation measures and awareness campaigns was high.