Den mörka sidan av ljuset

Sammanfattning: The spread of artificial light on Earth increases annually. One of many causes of this spread is due to increased street lighting and artificial light at night (ALAN). Lighting is one of the many necessities for people to feel safe. On the other hand, ALAN, which contributes to light pollution, negatively affects biological functions and thus biodiversity. The purpose of this study was to investigate whether people are willing to accept an adaptation of the lighting to reduce the impact on biodiversity. The study thus aimed to investigate the trade-offs made between safety and biodiversity when planning outdoor lighting. The study was formatted as a case study with a mixed- methods design. A literature review, an interview study, and a survey study were included in the mixed method. The survey was conducted with respondents from Adolfsberg in Helsingborg, Sweden. The results showed that the experts interviewed considered it important to have even lighting in the landscape, to examine where the lighting is to be set up in the environment, and to communicate. From the survey, it could be discerned that half of the respondents could accept a change in lighting due to consideration for biodiversity. This study expresses the need to plan area-specific in the future where both safety and biodiversity must be taken into account. Lighting interacts with other physical area-specific attributes in the landscape, such as shrubbery. Therefore, it is important to plan the outdoor lighting based on its environment as well as taking subjective experiences and species composition into account. It is possible to design for increased consideration, i.e., adjust the light spectra, intensity, and evenness to suit the specific area. Future challenges are to collaborate and communicate why changes in outdoor lighting are taking place to increase knowledge, which can increase understanding and acceptance among people. Key words: Safety; Street light; Light pollution; ALAN; Biodiversity; The City of Helsingborg; Municipality