ETC HE Report 2022/8: Review and Assessment of Available Information on Light Pollution in Europe

This report presents summarised information on the status of light pollution in the 38 EEA member states, based on published literature and remote sensing data of artificial light emissions at night. It aims to assess the current knowledge on light pollution and its adverse impacts on human health, biodiversity and ecosystems as part of the Zero Pollution Monitoring Assessment. Furthermore, an analysis of the legislative basis illustrates the political progress made to mitigate light pollution, especially within the EU countries. A spatial and temporal comparison of artificial light emission levels gives insight into the current status of light pollution.

11 Nov 2022

Kaja Widmer, Anton Beloconi, Ian Marnane, Penelope Vounatsou

This report aims to review the current knowledge on light pollution in Europe, as part of the Zero Pollution Action Plan. The key impacts of artificial-light-at-night (ALAN) on human health, biodiversity and ecosystems are summarised. Disrupted sleeping patterns, development of cancer, depressive disorders and weight gain received most scientific attention. However, evidence of an association between socio-economic status, urbanization, and light emissions suggests that the health effects of ALAN need further validation to infer causality and these results should be analysed with caution. Adverse effects on wildlife were linked to the alteration of the innate circadian clock controlling the behaviour of animals via natural light stimuli, which may result in altered behavioural patterns, reproduction, communication, or even physiological changes. Ecosystems such as natural night skies or dark environments serving as refuges for light-sensitive species are negatively impacted.  An analysis of the legislative basis revealed no common EU policy currently regulating light pollution, but progressive national legislations have been adopted in France and Croatia, as well as in regions of Italy and Spain. Other EU countries, such as Austria, Liechtenstein or Ireland, have only non-binding guidelines. Satellite imagery was utilised to model historical trends in Europe and compare light pollution levels spatially and temporally. Overall, the terrestrial surface of Europe has experienced a net increase in artificial light exposure, especially in the Eastern regions. Changes in light emissions were modeled for the two thresholds 2 nW/cm2/sr, above which at least a small ecological impact is expected, and 0.5 nW/cm2/sr, the lowest values measured by VIIRS. While the area exposed to light emissions of less than 2 nW/cm2/sr has decreased by only 1 %, the regions with less than 0.5 nW/cm2/sr have shrunk by 5.2 %. The Netherlands, Luxembourg, Poland, and Belgium recorded the largest increase in brightness between 2014/15 and 2020/21, and a decrease in light emissions was observed in Iceland, Ireland, and France.