The National Geographic Magazine has an excellent article about Light Pollution:
It was once thought that light pollution only affected astronomers, who need to see the night sky in all its glorious clarity. And, in fact, some of the earliest civic efforts to control light pollution — in Flagstaff, Arizona, half a century ago — were made to protect the view from Lowell Observatory, which sits high above that city. Flagstaff has tightened its regulations since then, and in 2001 it was declared the first International Dark Sky City. By now the effort to control light pollution has spread around the globe. More and more cities and even entire countries, such as the Czech Republic, have committed themselves to reducing unwanted glare.
On my recent trip to Hawai’i I found I really enjoyed visiting the Big Island, home to a swag of observatories atop Mauna Kea. [See Mauna Kea: the sacred high desert.]
The whole island enjoys very strict light pollution laws to preserve those precious dark skies.
The article adds:
Unlike astronomers, most of us may not need an undiminished view of the night sky for our work, but like most other creatures we do need darkness. Darkness is as essential to our biological welfare, to our internal clockwork, as light itself. The regular oscillation of waking and sleep in our lives — one of our circadian rhythms — is nothing less than a biological expression of the regular oscillation of light on Earth. So fundamental are these rhythms to our being that altering them is like altering gravity.
There is so much we could achieve by reducing light pollution: better health, less expense for power (generation and use), greater access to the wonders of the night sky, fewer problems for birds and animals disoriented by lighted towns and cities, a less ‘harsh’ environment.
It seems such an obvious thing to do.
A linguistic curiosity: air pollution is pollution of the air; water pollution is pollution of the water. Light pollution is by light.