According to Science magazine, the average night sky brightened by 9.6% per year from 2011 to 2022. Many of us have experienced our own encounters with the reduction of nighttime quality of life because of poorly positioned or excessively bright lights.

A recent documentary on the subject of Maine’s skies, “Defending the Dark,” described the public health effects of constant over-bright nighttime artificial light. More light at night is linked to cancer; glare threatens public safety of motorists and pedestrians, and more light takes the night sky away from us earthbound dwellers, something all flora and fauna have evolved under for millions of years.

What happened? In short, new LED outdoor lighting came along, with the capacity to emit much brighter blue-white light, replacing the more mellow and gentler hue, friendly to the human eye, that we were accustomed to.

It can take a while to sort out the beneficial effects and negative effects of a new technology. LED streetlights save between 40% and 60% in electricity use and carbon footprint, which is very beneficial. They also introduce glare, light pollution and light trespass. They obscure the night sky, something essential to our well-being.

There is a long tradition in literature and religion of using “light” as a metaphor for understanding or acquiring knowledge. We “see the light” or we seek “the light at the end of the tunnel.” If what is at the end of the tunnel is nighttime, it is still largely visible because of moonlight and stars.

Evolution has given us eyes with cones and rods, the latter attuned to nighttime vision and fully activated by about 20 minutes after nightfall. But it seems this is forgotten by marketers of streetlights and all manner of other outdoor lighting. Night is the enemy? Tell that to evolution.


Its relative cheapness enables LED lighting to leap beyond outdoor lighting’s traditional use: the illumination of sidewalks and crosswalks for pedestrian and bicyclist safety and comfort.

Starting with gas station canopy lighting, then outdoor lighted signs, storefront illumination and parking lot lights, there seems to be competition between retail and other commercial entities to attract motorists and other passers-by with brighter and brighter LED lighting. Have you noticed but shrugged off ever-accumulating unnecessary outdoor lighting where it had not been before? Maybe this is just progress? It’s not. We can do better.

Firstly, we can all insist that our municipalities, counties and state agencies, including the Maine Department of Transportation and the Turnpike Authority, abide by the laws already on the books for mitigating sky glow, light pollution and light trespass. Keep your light to yourself. In this regard, the International Dark-Sky Association provides a set of outdoor lighting principles that could be adopted by municipalities (some have already, Rangeley for instance), counties and the state to guide the management of the negative effects of LED lighting while promoting its positive effects.

The first principle is that all lights should have a clear purpose. If municipalities and the state were clear that outdoor lighting is first and foremost for sidewalk and street pedestrian and bicyclist use, then regulation of other outdoor lighting to avoid light pollution, based on nuisance law, would be self-evident.

Artificial light should only be directed where it is needed, with shielding required to mitigate light pollution and trespass.

Light should be no brighter than necessary. Whether walking down your neighborhood street or at your backyard barbecue, unless the amount of light is commensurate with what you need to see, the excess light is not only wasteful but annoying.  Trying to duplicate daytime in the nighttime is likely to cause a veiling fog of shadow-less glare.

Light should be used only where it’s useful. After 11 p.m., for instance, businesses could be required to turn off extraneous area-wide lights (used for advertising rather than security), starting with gas station canopies. Security lighting should be restricted to the walls of buildings by downward-shining fixtures. Outdoor display areas of car dealerships and the like? Use ground-level bollard gentle lights after 11 p.m. The public has no iron-clad bargain with you to have your vehicles or merchandise next to the street aglow with powerful high-brightness lights flooding onto the street, neighboring properties and the sky. That’s your choice, not the public’s.

Finally, lights in warmer colors should be used wherever possible.

Like Rangeley, other municipalities could be working on better administering their lighting ordinances or introducing new ones. If we want to stop the constant increase of outdoor artificial lighting in Maine, it’s doable. It’s up to us.

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