There it was, a faint orange glow in the northern sky. Could it be, at long last, the northern lights? I stared at the glow while the cold night air nipped at my cheeks. The light seemed awfully uniform, and was not moving. Weren’t the northern lights supposed to be mostly green anyway? Or if orange, not this dull shade?
That dull shade of orange was familiar. I had seen it before, but always near cities. It wasn’t the northern lights, but “skyglow,” the reflection of electric lights, usually street lights, into the night sky. I never expected to see skyglow from my back porch in rural Vermont, but light pollution – and skyglow is just one form of it – is an increasing problem, not just in cities, but in rural areas like ours.
“Twenty years ago, one could actually see the Milky Way in Manchester (New Hampshire),” says Mike Pelletier of the New Hampshire Citizens for Responsible Lighting (NHCRL). “Now, one cannot see it, and several major constellations have also been replaced in the night sky by an orange glow.”
But light pollution is not just skyglow. When your neighbor’s security light shines in your eyes when you are trying to sleep, that’s “light trespass,” another form of light pollution. Glare is another light pollution problem that can happen anywhere there is an electric light. If the light is poorly aimed and shines in your eyes, that’s glare, and it’s particularly dangerous when you are driving.
Skyglow is not limited to cities as large as Manchester. Mike Stebbins, a NHCRL member, says that Conway, New Hampshire, has massive skyglow, and Claremont, New Hampshire is getting there. Other New Hampshire cities with notable skyglow are Keene and Tilton. In the Upper Valley, Hanover, Lebanon, and White River Junction produce notable skyglow. In Vermont, there is skyglow not only from cities such as Burlington and Rutland but also from smaller towns such as Randolph and Morrisville. Tiny Ludlow, Vermont, appears to be the source of the skyglow in my backyard.
It’s not that outdoor lighting is bad. We need lights so we don’t back into other cars in parking lots, so we feel safe walking at night, and to keep burglars away from our homes. It is possible, however, to do all those things without robbing the sky of its darkness.
In 1996, the Chittenden County Regional Planning Commission in Vermont published a booklet that’s still considered one of the most understandable explanations of light pollution around. While you may not want to curl up with it in front of the fire, in a mere 48 pages it tells you everything you need to know about outdoor lighting, including how a town can be safe and well-lit while saving energy and eliminating light pollution. For example, to reduce skyglow and glare, one solution is using “full cutoff” fixtures that prevent light from shining above the horizontal.
Stargazers are usually the first to notice light pollution, but it affects other living things too. Sea turtles are drawn inland by electric lights instead of toward the ocean after hatching. Every year thousands of migrating songbirds crash into lighted skyscrapers or lit communications towers and die.
Thanks to our mountains, Vermont and New Hampshire have fewer towers that are over 199 feet tall than other parts of the country. That height is important because at 200 feet federal law requires a light on top of the tower for aviation safety. While communications towers themselves cause some problems for birds, it’s the lights on the towers that seem to cause the most casualties.
The worst cases seem to be foggy nights, nights with low clouds in spring or autumn, and towers lit with steady or pulsing red lights. Night migrating songbirds are sometimes unable to leave the lit area. They circle the tower, creating a whirlwind of birds. They may crash into the tower, guy wires, each other, or fall from the sky exhausted. While all species of migrating songbirds are vulnerable to this fate, thrushes, vireos, and warblers appear to be the most vulnerable.
Two years ago, the U.S. Fish & Wildlife Department published a set of guidelines for communications towers, which included advice on light. White lights are better than red. Strobe lights are better than steady lights, and the flashes should be as few and as far between as allowed by the Federal Aviation Administration.
Light pollution steals the stars from the sky (or at least our view of them) and the birds from the air. It creeps up on us under good intentions, but is a thief just the same. We can bring back the darkness of night with simple techniques, consistently applied. We need only to notice and care.