Research note: Red light to mitigate light pollution: Is it possible to balance functionality and ecological impact?

The widespread use of electric lighting has revolutionised society but brought unintended consequences, notably light pollution, impacting ecosystems and human circadian rhythms. Concerns about anthropogenic light at night (ALAN) have prompted innovative solutions, such as spectral tuning of light sources. In Europe, a recent focus involves the enforcement of red light in outdoor settings to minimise ALAN’s impact, particularly on bats. This mini review synthesises literature to provide an overview of the advantages and disadvantages of the use of red light outdoors. There is a need for further examination of the potential ecological consequences of red light, considering challenges in lighting design functionality and broader impacts on diverse species.