For over two centuries, American streets and byways have been increasingly illuminated by streetlamps, lit by oil, coal, gas, carbon arc, incandescent and high-intensity gas discharge. This steady creep has led to a problem that anyone involved in engineering, designing and installing exterior lighting should be aware of—light pollution.

According to the International Dark-Sky Association (IDA), light pollution is the inappropriate or excessive use of artificial light. IDA describes it as “a side effect of industrial civilization. Its sources include building exterior and interior lighting, advertising, commercial properties, offices, factories, streetlights, and illuminated sporting venues.”

It causes glare or excessive brightness that causes visual discomfort; skyglow, which refers to the brightening of the night sky over inhabited areas; light trespass, which denotes light falling where it is not intended or needed; and clutter, which, as the name implies, is “bright, confusing and excessive groupings of light sources.”  

Learning from citizen scientists

A study that gathered data from 50,000 “citizen scientists” all over the globe, drew some disturbing conclusions. Published in January 2023 in the journal Science, “Citizen scientists report global rapid reductions in the visibility of stars from 2011 to 2022,” warns of the looming problems of light pollution in the environment. These data gatherers took samples of light brightness from their vantage points over nine years. 

One conclusion that caused caution was that “the visibility of stars is deteriorating rapidly, despite (or perhaps because of) the introduction of LEDs in outdoor lighting applications. Existing lighting policies are not preventing increases in skyglow, at least on continental and global scales.”

What could this mean? It probably is fair warning that we could do more to limit light pollution from exterior lighting, specifically LED lighting. The IDA advocates for better ways to light the world that can help prevent light pollution.

In a January 2023 article in Scientific American, “Light Pollution Is Dimming Our View of the Sky, and It’s Getting Worse,” astronomer and science communicator Phil Plait wrote, “Groups like the [IDA] advocate not for more lighting but for more intelligent lighting; smarter streetlights that concentrate their light downward is one example. Because these lights offer more efficient illumination, they save energy, too, eventually paying for themselves. The IDA offers advice on how to contact local authorities to install better fixtures and create ordinances to lower pollution.”

There is also rising resistance from citizens who do not want their environment polluted with light. Last summer in Hancock County, Maine, voters adamantly opposed a large, open-pen salmon farm proposed by a fish purveyor. Voters felt “the fish farm would also bring noise, light pollution, and daily boat traffic to this remote and beautiful area, including the transporting of salmon excrement across the bay.”

Finding solutions to light pollution

Innovators are developing new solutions to help curb the problem of light pollution. For example, in the past year, E Ink, a leader in digital paper technology, received the IDA’s Dark Sky Certification as the first display technology to be certified by the organization. It uses reflective technology so displays do not emit any light, rather relying on ambient lighting to be viewed. Instead of a bright nighttime display, it uses a simple, small LED strip, which can illuminate the display without generating or wasting stray light and adding to the prevalence of light pollution.

In addition to many new advances in technology, the IDA promotes local ordinances to control the incidence of light pollution. According to its position, as stated on its website: “Outdoor lighting ordinances or codes are a great tool for ensuring that municipalities implement good, safe outdoor lighting. A well-written ordinance, with proper lighting installed, will save the public money and increase safety. Thousands of cities have adopted such codes and they can be a great tool for a community to use to control light pollution, including glare, light trespass and skyglow.”

Electrical contractors should pay attention, because LEDs have cause big advances in exterior lighting. Sustainability has always been factored into such lighting. Light pollution grows tacitly, but could just be the dark side of brighter lights.

stock.adobe.com / Jorge Ferreiro