More U.S. cities dimming the lights

USA Today- "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."

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.

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.