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Designing outdoor lighting efficiently - reducing light pollution

The illumination of night landscapes by artificial lighting increases globally by about 2 to 6 percent per year, with effects on people and nature. A new guide describes how municipalities can minimize light pollution by making their street and building lighting more efficient. Researchers from the Leibniz Institute of Freshwater Ecology and Inland Fisheries (IGB), the Federal Agency for Nature Conservation (BfN) and the University of Münster have now jointly published the guide on redesigning and retrofitting outdoor lighting.


About 30 percent of vertebrates and even more than 60 percent of invertebrates are nocturnal and can be affected by artificial light at night. The protection of the night must therefore be understood more strongly than before as a fundamental task of nature and landscape conservation, says Prof. Dr. Beate Jessel, President of BfN. The guide to action now published shows that it is possible to minimise the ecological damage caused by artificial lighting. It contains numerous concrete recommendations for action and practical tips for outdoor lighting.

Good lighting is efficient and reduces power consumption while increasing visibility and safety. It is aesthetically pleasing and minimises environmental impact. Many of the measures presented in the action guide are also simple and inexpensive to implement, is how IGB researcher and study leader Dr. Franz Hölker sums up the requirements. Franz Hölker's team is a leader in Germany and internationally in research into so-called light pollution. This is the term used when artificial light at night has a negative impact on humans and light-sensitive creatures. The guide is largely based on scientific findings that his working group, together with researchers from the BfN and the University of Münster, have gained over many years of work.

In the absence of explicit regulations for outdoor lighting, industrial standards for lighting are often treated in practice as legal provisions. In many cases, even the minimum requirements of the technical standards are far exceeded in order to exclude possible claims for damages, for example in the event of traffic accidents, and to prevent accusations that the street lighting does not comply with the state of the art. The result is that outdoor areas are often illuminated much more than necessary, with possible negative consequences for people and nature. However, it is possible to minimise the ecological impact of artificial lighting and at the same time meet social requirements such as safety and aesthetics.

The first author, Dr. Sibylle Schroer from the IGB, gives examples of solutions: Municipalities should use luminaires that do not emit light upwards. The illuminance should be as low as possible and cold white light with a high blue light content should be avoided. This is because the circadian system of higher vertebrates and humans is particularly sensitive to blue light. The use of warm white light can mitigate the negative effects on many organisms and is often perceived as more pleasant by humans.

The interdisciplinary collaboration with the lawyer for environmental and planning law, Benedikt Huggins from the University of Münster, uncovered gaps in environmental law in order to better protect organisms from exposure to poorly installed, unnecessary or excessively bright artificial light in the future. The recommendations were made on the basis of the two research and development projects Analysis of the effects of artificial light on biodiversity, Determination of indicators of impairment and derivation of recommendations for action to avoid negative effects in the context of interventions and Light and glass: Legal issues of the endangerment of species by light and glass, funded by the Federal Ministry for the Environment and accompanied in terms of content by the BfN.

The restriction of light pollution brings further advantages, for example in terms of energy savings and thus climate protection, as well as for human health. The guide offers those responsible in local authorities as well as those responsible for lighting, urban and regional planning a free professional decision-making aid to actively promote the conscious use of artificial light.

More information here

Source: Federal Agency for Nature Conservation, press release, 20.01.2020


Keywords: Greening / climate adaptation, DE-News, Artificial light, Media, Near-natural open space design, New books and studies, Permaculture, Transition Town, Wildlife/animal friendly construction, Ecology
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