Light pollution is everywhere. The glow on the distant horizon of an approaching town or city. Attempting to look at the stars on a perfectly clear night only to see a few when you know a thousand points of light should be visible. Flying at night and gazing out the window to see dots of lights over vast areas from coast to coast. This is light pollution, and it comes in many forms.
What is light pollution?
Light pollution is caused by an excessive use of artificial light and it can have serious consequences on our environment. Many forms of outdoor night lighting, like street and parking lot lights, can be a direct cause. They’re often overly bright, poorly targeted, and inefficient. Rather than being shielded so light is directly targeted downwards, the light spills into the sky, wasting electricity, and what’s more, failing its intended purpose to illuminate the area below.
The four types of illumination pollution
There are four types of light pollution, but all are equally harmful.
Glare is an excessive brightness that can discomfort or even impair vision over time.
Skyglow is that example we listed earlier: a brightening of the sky or “glow” over cities and other heavily populated areas.
Light trespass brings us back to our streetlight example: light falling or spilling somewhere else as opposed to where it was intended. When area lights aren’t properly shielded they illuminate non-intended locations wasting energy and creating light trespass.
Clutter is the fourth type of light pollution and is defined as a “bright, confusing, and excessive grouping of light sources.”
Each of these types of light pollution are harmful in their own way and combined negatively impact our environment, ecosystems, energy consumption, safety, and even our health.
Effect on human health
It’s not just our eyes that suffer from light pollution, but our circadian rhythms, too. All of this artificial lighting makes it hard to experience a truly dark night, which can mess with our body’s production of melatonin, and ultimately, our sleep cycle.
While different types of lighting pose different risks, exposure to artificial lighting in general suppresses the production of melatonin, a hormone responsible for inducing sleep, boosting our immune system, lowering cholesterol, and maintaining proper function of the thyroid, ovaries, testes, and adrenal glands.
Blue light – which comes from phone screens, T.V.s, etc. – is particularly harmful to human health, especially our circadian rhythms.
Light pollution harms wildlife and ecosystems
Humans aren’t the only creatures whose health is affected by artificial lighting. Outdoor lighting severely impacts animals’ circadian rhythms and disrupts ecosystems. Glare from nighttime light has been found to confuse nocturnal species, hinder predators who use darkness to hunt, and expose prey who use darkness to hide.
In recent years, we’ve seen more and more nocturnal animals, like opossums, out during the day. Even worse. people are under the misconception that nocturnal animals coming out in daylight is an indication of sickness or rabies when, it’s just confusion from light pollution.
Artificial light has also been known to confuse baby sea turtles as it draws them away from the ocean, disrupt the migration of bird that rely on moonlight and starlight for navigation, and confuse amphibians like frogs and toads who use nighttime croaking as part of their breeding ritual.
Light pollution costs money and wastes energy
Despite all of the harm that light pollution causes to both people and wildlife, outdoor lighting continues to be run in overabundance and is a huge source of wasted energy and money.
In just one year in the U.S., outdoor lighting uses enough to cover New York City’s total electricity needs for two whole years. That’s roughly 120 terawatt-hours of energy being used just to illuminate streets and parking lots.
Going back to our street light example, the IDA estimates that unshielded lights are wasting at least 30 percent of all outdoor lighting in the U.S. That may not sound like much, but to put that in perspective, we’d have to plant 875 million trees annually to offset the 21 million tons of carbon dioxide released by all this lighting. The cost of planting those trees wouldn’t even come close to the $3.3 billion wasted by all that unnecessary light.
What can we do?
Managing light pollution is receiving increasing attention from municipalities and companies working with environmental organizations to lessen its impact. Methods being adopted to reduce impact include improving light projection design and installation of glare shields, optimize installation spacing, decreasing light output, and using long-wavelength lighting.
EcoCentricNow sells a variety of LED lighting products that reduce light pollution while reducing energy usage and maintenance cost.