The Dark Sky Movement: Light Pollution for Dummies

Think you’re doing your part for the environment by sorting your recyclable waste and carpooling? Carbon emissions and landfill mass aren’t the only types of pollution that you need to consider.

Light pollution is a well-established phenomenon that has many negative impacts on the planet. Here’s why it’s so important and how dark-sky movements and smarter lighting standards are leading the charge to put an end to the problem.

What Is Light Pollution?

Light pollution is a general term that encompasses a range of human-made and natural conditions. Also referred to as photopollution, it consists of anything that results in misdirected or unwanted artificial illumination.

Photopollution takes many forms, including

• Light trespass, also known as nuisance light, or direct light that spills beyond the boundaries of an illuminated property,
• Skyglow, or bright nighttime skies caused by direct illumination and reflections from illuminated surfaces,
• Glare, or potentially discomforting, disabling or blinding light cast by improperly positioned lighting,
• Light clutter, or groupings of lights in clumps that can cause aviation hazards or road accidents, and
• Over-illumination, or the wasteful use of unnecessary lighting.

Why Does Light Pollution Manner?

Most people are concerned about light pollution because it’s simply annoying. For instance, if you can’t sleep because your neighbor’s security floodlights are constantly shining through your windows, it makes sense that you’d be perturbed. In reality, however, personal preferences may be the least of humanity’s worries when it comes to photopollution.

Energy Waste

Lighting consumes massive amounts of power. By some estimates, the energy produced to supply U.S. residential outdoor lighting releases around 15 million tons of carbon dioxide annually, or about as much as 3 million cars.

True, it’s difficult to determine exactly how much of this electricity goes to waste. The fact that most major cities appear clouded in a perpetually bright evening haze, however, clearly indicates that the way we use lighting could stand to be more efficient.

Ecosystem Disruption

Are you having trouble sleeping at night because of a poorly aligned streetlight? Consider how the nearby wildlife must feel.

Academic research has shown that light pollution can wreak havoc on the lives of various animals from songbirds and insects to larger mammals, reptiles and amphibians. The ill effects of this illumination may include problems like

• Confusing migratory birds into making suicidal dives into lit window panes or being unable to follow the moon properly on long journeys,
• Throwing songbirds’ sleep cycles into disarray, which prevents them from mating properly to carry on their species,
• Decreasing small mammals’ tendency to forage for food, which could also harm the predators that feed on them,
• Blinding animals like deer so that they cause vehicle accidents,
• Bedazzling sea turtle hatchlings into moving away from the ocean so that they eventually die of dehydration or exhaustion, and
• Attracting insects to light sources where they can no longer fulfill their role as critical blocks in the food chain.

Other Challenges

Light pollution may also contribute to negative outcomes like harming human health by disrupting people’s circadian rhythms. One U.S. study even suggests that nighttime glare interferes with chemical reactions that usually help clear up human-made smog produced earlier in the day.

What Can You Do About Light Pollution?

Light pollution is an undeniable problem. Fortunately, there are many ways to fight back without having to turn off all of your lighting and TVs when the sun sets.

Non-profit organizations like the International Dark-Sky Association offer a number of suggestions on how to respect your nocturnal surroundings. For instance, you can

• Use light-blocking window coverings,
• Put your outside lights on timers and motion detectors to reduce unnecessary usage,
• Switch to less-intrusive light sources, like amber LEDs and low-pressure sodium lamps.

Many municipalities enact ordinances to get photopollution under control. If you’d rather not wait for the law to make you a more responsible consumer, however, you can upgrade to dark-sky lighting fixtures specifically designed to help eliminate problems like glare and light trespass. It may also be helpful to redesign your fixture placement for heightened efficiency.

You may decide to throw your full weight behind the dark-sky movement by joining a local advocacy group or simply reconsider how you use outdoor lights. In either case, taking a proactive stance on photopollution is a good idea. At the very least, you’ll lower your energy bills, stop the birds from chirping all night long and make your neighbors happier.