Dark-sky Movement

The dark-sky movement is a campaign by people who want to reduce light pollution. Advantages include making more stars visible at night, reducing the effects of unnatural lighting on the environment, and cutting down on energy usage. Earth Hour and National Dark-Sky Week are two examples of such efforts.

The movement started with professional and amateur astronomers alarmed that nocturnal skyglow from urban areas was blotting out the sight of stars. For example, the Griffith Observatory in Los Angeles is useless for astronomy, because of daytime smog and night time light pollution, while world-famous Palomar Observatory is threatened. For similar reasons, astronomers in Arizona helped push the governor there to veto a bill in 2012 which would have lifted a ban on illuminated billboards.

The movement has spread with groups like the International Dark-Sky Association, as other concerns have been raised. For example, according to the Burlington Free Press nocturnal animals can be harmed by light pollution because they are biologically evolved to be dependent on an environment with a certain amount of hours of uninterrupted daytime and nighttime. The over-illumination of the night sky is affecting these organisms (especially birds). This biological study of darkness is called scotobiology. Light pollution not only affects animals and plants, but also energy costs in the U.S alone are 2.2 billion due to over-lighting. Light pollution has also been found to affect human circadian rhythms.

The dark-sky movement works to encourage the use of full-cutoff fixtures that cast little or no light upward in public areas and generally to encourage communities to adopt lighting regulations. A 2011 project is to establish "dark sky oases" in suburban areas.