Recently, France instituted one of the world’s most comprehensive lighting ordinances, and all over that country – even in Paris, the City of Light – late nights have gotten darker.
From 1 am until 7 am, shop lights are off and lights inside office building are dark an hour after workers leave. These and other elements of the new regulations are designed to reduce energy consumption and lower carbon dioxide emissions.
But there is more to the lighting control measures than energy conservation. The new regulations are trying to reduce the impact of artificial lighting on the natural environment. Research into light pollution is revealing that disrupting natural patterns of light and dark has profound effects on the structure and function of ecosystems.
Artificial light alters circadian rhythms and long-established patterns of mating, migration, feeding, and pollination. Disruption of these activities ripples through ecosystems with untold effects on animal species. For example, street lighting influences the migratory patterns of Atlantic salmon. And we are increasingly realizing that the disruption of circadian rhythms has impacts on human beings as well.
Light pollution has been recognized as a problem for a while. Until recently, the emphasis has been on astronomical light pollution erasing our view of the stars. But the broader effects of artificial light on the environment are now getting real attention. Issues of safety and security cannot be ignored but learning how to use light effectively rather than just abundantly is within our capabilities. There are many reasons to change the way we light up the night.
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Web Links
Bringing Back the Night: A Fight Against Light Pollution
http://e360.yale.edu/feature/bringing_back_the_night__a_fight_against_light_pollution/2681/
Photo, taken on June 5, 2009, courtesy of Jim Trodel via Flickr.
Earth Wise is a production of WAMC Northeast Public Radio. Support for Earth Wise comes from the Cary Institute of Ecosystem Studies in Millbrook, NY.