Is Your Lighting Dark Sky Friendly?
As anyone who has ever flown over a city at night knows, intricate patterns created from illuminated buildings, streets and neighborhoods can be mesmerizing. However, the use of artificial light at night can also have a serious impact.
So, in honor of International Dark Sky Week, from April 5 - 12, we're digging into the dark sky movement, which is an international effort aim to preserve dark sky viewing and reduce light pollution.
When not kept in check, artificial lighting can disrupt wildlife, effect human health, waste energy, and erase our view of the universe. For wildlife, too much light or an interruption in darkness can impact nocturnal instincts, migration patterns, and biological rhythms. In humans, it has been linked to everything from sleep disorders to diabetes, according to a report by the American Medical Association.
A big contributor is the use of blue-rich LEDs for outdoor lighting because blue light scatters a lot further through the atmosphere than other light, even when it’s covered.
Over the years, cities and municipalities have been opting for cheaper, more efficient LEDs for streetlights over the high-pressure sodium lamps that give off the familiar warm yellow glow. And because cooler, blue LED light sources are the most efficient LEDs in terms of the conversion of electricity to light, making it some of the world’s lowest electricity cost to produce, they’re also being widely used in parking lots, malls, office buildings, stadiums and other structures.
However, all this light is contributing to what’s called sky glow, or light pollution. Sky glow increases the brightness of the dark areas of the sky, which reduces the contrast of stars or other celestial objects against the dark sky background.
For the non-profit International Dark-Sky Association (IDA) and other groups like them, it’s a disturbing trend. They try to help communities adopt dark sky regulations that call for energy efficient precision lighting approaches. These include efforts such as eliminating uplight in public areas and requirements for lower illumination architectural LED lighting that won’t put visibility at risk.
While sky glow is worrying, in contrast to some modern-day complex environmental problems, many existing solutions to light pollution are simple, cost-effective, and instantaneous.
Here are several things municipalities, commercial real estate developers ‑‑ even homeowners ‑‑ can do to mitigate LED’s impact.
Warm CCT: The use of warmer color temperatures (CCT) when selecting LED lamps is a brilliant way to protect our ecosystem as well as cutting down energy use. IDA recommends the use of only warm light sources for outdoor lighting.
Motion sensors, dimmers and timers: Lighting may make people feel protected while walking around the streets, but there are many times when light isn’t needed. The use of motion-sensors will reduce this kind of pollution, as well as cut down on the overall costs of electricity. Another way is to use dimmers and timers to decrease average illumination levels and save even more energy.
Control through optics: Over the years, manufacturers have designed lighting fixtures with better, more efficient optics. These newer types of fixtures use reflectors to control the beam angle, creating either crisp-edged or diffused light, or to concentrate light in certain areas while limiting it in others. Because they rely upon precision rather than sheer power, these luminaires can do more work with fewer watts. Another smart alternative is selecting a full-cutoff luminaire. Light is targeted to the area it's needed, and no light is lost above the luminaire, contributing to sky glow.
Task lighting: Lighting should be where you need it, when you need it, in the amount necessary. It's not necessary to over-light an area. Task lighting can minimize wasted light by localizing lighting to exactly where it's needed to suit the task at hand. Certain spaces are used sporadically, and certain tasks require less illumination. Always consult your municipality’s recommendations.
Tackling light pollution doesn’t have to be hard or mean giving up high-quality products. In fact, many solutions are low-tech, cost-effective solutions. Through education, we can easily be changemakers in safeguarding our natural environment.
Want an easy way to find dark sky friendly lighting?
IDA’s Fixture Seal of Approval provides objective, third-party certification for luminaires that minimize glare, reduce light trespass, and don’t pollute the night sky.