Dark-sky legislation — laws requiring such measures as shielding outdoor lighting to reduce light pollution — has been embraced by about 300 counties, cities and towns.
More than 50 state bills have been introduced in the past two years, and seven were enacted. Eighteen states —Arizona, Arkansas, California, Colorado, Connecticut, Hawaii, Maine, Minnesota, Missouri, New Hampshire, New Mexico, New York, Oklahoma, Rhode Island, Texas, Vermont, Virginia and Wyoming — have adopted dark-sky legislation in recent years, according to Bob Parks, executive director of the Tucson-based International Dark-Sky Association.
EARTH HOUR: Landmarks, cities worldwide cut power
The laws have won support in states such as Texas, home to several military bases, because lights at night can interfere with military drills. Trying to simulate flying over remote parts of Afghanistan is difficult when skies are aglow from city-light glare.
"It's a broad environmental issue, and it's also a safety issue," Parks says. "It's a pure waste of energy, dollars, and it contributes to greenhouse emissions. ... For every watt of electricity used needlessly, somewhere a coal power plant is generating that electricity."
The association, which has 5,000 members worldwide, was founded in 1988 by an astronomer in Tucson who noticed an impact of city lights on stargazing. Local ordinances were enacted to direct lights toward the ground instead of the sky and to not light areas that don't need illumination, Parks says.
Since then, evidence has mounted that nighttime lights disturb animals and ecosystems. This month, findings presented at the American Geophysical Union in San Francisco showed that sky glow over cities interfered with chemical reactions that naturally clean the air at night.
Read the entire article: http://www.usatoday.com/news/nation/environment/2010-12-29-light-pollution_N.htm?csp=hf