One hundred years ago, stargazers in the Baltimore area might have seen some 2,000 stars as they craned their necks toward the night sky.
“Now you are lucky if you can see three,” said Tom Burns, director of the Perkins Laboratory at Ohio Wesleyan University.
Light from streetlamps, buildings, billboards and flag poles is often directed toward the sky, or the light bounces off surfaces, shattering the darkness.
The result is light pollution, which wastes energy, adversely affects wildlife and robs astronomers of their subjects, experts said.
“Light pollution is an environmental problem that is growing,” said Bob Gent, president of the board of directors for the International Dark-Sky Association. “There are some dire consequences that most of us don?t even think about.”
Among the adverse affects of too-bright lights is that the glare can create unsafe conditions for the aging population, particularly when they drive at night, Gent said.
Wildlife also is feeling the burn. Migrating birds that use the stars to guide them become disoriented, and some sea turtles avoid the brightly lit beaches where they should be nesting, Gent said.
“Lights at night are adversely impacting every species in one way or the other,” he said.
The solution seems simple: Use the right amount of light only where it is needed, experts said.
Pointing streetlights down at the street, rather than into the sky, can help, Burns said. Full cutoff lighting fixtures limit the amount of light that escapes above a horizontal plane.
Another option is the use of low-pressure sodium bulbs, which are less offensive than full-spectrum white light, Burns said.
“All of these things will save energy and save money and the save the sky,” he said.
However, the cost of replacing existing fixtures is prohibitive, according to a 2002 report from a state task force charged with reviewing lighting efficiency and light pollution in Maryland.
Opportunities exist to use efficient lighting in new construction, the report states, and the state should require properly designed lighting systems.
