Image: Global city lights. The Eastern U.S., Europe, and Japan are brightly lit by their cities, while the interiors of Africa, Asia, Australia, and South America remain (for now) dark and lightly populated. (Image by Craig Mayhew and Robert Simmon, NASA GSFC. Based on data from the Defense Meteorological Satellite Program).
by Christine Muller
Light pollution is not only a nuisance for star gazers. While artificial light can impair human health by affecting the circadian rhythm, it has a much stronger impact on plants and animals, for example, it disrupts the life of nocturnal animals. Migratory birds are confused by light pollution and may migrate at the wrong time or fly off course. Insects are attracted to light with deadly consequences. The loss of birds and insects is more significant today than in the past because insect and bird populations have been rapidly declining world-wide. There are many known and unknown reasons for their decline, and light pollution is just one factor. A scientific paper* ends with the conclusion: “Darkness is indispensable for the healthy functioning of organisms and whole ecosystems.”
This same paper recommends the following actions:
1. Light only where needed
2. Don’t overlight
3. Don’t waste light
4. Shine light downwards, using shields and reflectors
5. Light only when needed – use sensors where possible
6. Light with energy efficient sources such as LED’s and compact fluorescents
*Source: Light Pollution and Impact of Light Pollution by Dr. Rasna Rajkhowa, International Journal of Science and Research (IJSR),Volume 3 Issue 10, October 2014, p. 7.