What can we do against light pollution?

The LoNNe participants have gathered a lot of evidence, that high quality lighting can make a difference.

The Loss of the Night Network has elaborated recommendations to avoid common mistakes in outdoor lighting. Find here:


The green public procurement (GPP) 2020 aimed to mainstream low-carbon procurement across Europe in support of the EU’s goals to achieve a 20% reduction in greenhouse gas emissions, a 20% increase in the share of renewable energy and a 20% increase in energy efficiency by 2020. Find here

LoNNe strongly advises to significantly reduce the current proposed minimum street lighting levels (luminance and illuminance) in the street lighting norm  EN 13 201, find here the reasons and the LoNNe objection to the street lighting norm EN 13201.

Measures against light pollution

Artificial light has a purpose, for example to illuminate the walkway. Light spill into the sky or adjacent habitats are polluting trespasses. Full shielding of light sources is useful to guide the light on target areas and avoid stray light. Visibility is rather a matter of contrasts and light uniformity, than of light intensity. Sustainable lighting planning will use low light intensities, because any light used in too high intensity will contribute to a greater extent to the accumulation of ALAN in form of skyglow. Low intensities, shielding of light sources and reducing the per capita number of lighting points can lower the contribution to skyglow and thus its environmental impact. Especially short wavelengths interfere with star visibility. Also the circadian clock of higher vertebrates, including humans, is the most sensitive to this part of the spectrum. Warm white or yellow light is recommended to reduce the negative impact.

The following five guidelines help to detect and reduce malpractices of outdoor lighting:

  1. Direct the light to where it is needed

  2. Reduce the light intensity to the minimum needed

  3. Use light spectra adapted to the environment

  4. When using white light, then in ‚warm‘ colour temperature (less than 3000 Kelvin)

  5. Limit the use of light to when it is needed