Audience: Middle and High School Students
An overhead shot of a city at night. Image by Sasha Kaunas from Unsplash.
From above, it seems that the stars have fallen to Earth. Light pulsates in fragments scattered across the strip of land, collecting in a massive constellation. A closer look will reveal the steel structures that hold up these celestial bodies, only to find that these lights aren’t astral at all. It’s simply New York City at night, flashing billboards, traffic lights, and street lamps setting the city aglow. What many don’t realize is this artificial illumination is an unacknowledged pollutant, with damaging effects disguised by the bright wonder of light. Light is blocking out the stars, crippling animal migration patterns, increasing the amount of CO2 in the atmosphere, and disrupting sleep cycles. While the capabilities of humanity and light have stretched far past our fire-sparking days, we must question if our impacts are always positive. How far do we bend nature to our will until it sustains damages beyond repair?
Essentially, light pollution is the excessive usage of man-made light. Though seemingly harmless, with an overabundance of light comes terrible consequences that deeply affect the Earth’s natural systems. There are three formal variations of light pollution: glare, skyglow, and light trespass. Glare is a superfluous amount of light that triggers a visual reaction, often caused by extreme brightness through road lamps, headlights, and street signs. Skyglow is the term used to describe the decreased visibility of the moon and stars in the sky, often in urbanized areas with prevalent light usage. Light trespass is when light is found in undesired places, like unwanted street lights spilling through a bedroom window at night, disrupting the inhabitant’s sleep. All these forms of light pollution adversely impact the environment in harmful, but not irreversible, ways.
At this point in time, “light pollution prevents nearly 80% of people in North America from seeing the Milky Way in the night sky”(Greenfieldboyce). The inevitability of the stars’ disappearance is frightening, but what’s more alarming is the fact that most of the general public is unaware of this issue, or worse, doesn’t seem to care at all. Many associate light to safety, warmth and health. Cities are often well-traversed and highly populated, tourists flocking brightly-lit street corners, attracted to the glow of the towers. Sight-seeing and traveling to see these light displays is common, gasping and fawning over the man-made constellations. Light has a celebratory connotation as evident in our practices; holidays consist of stringing colored lights around houses, trees are swathed each December in Christmas-hued illuminations, July Fourth prompts firework shows in the sky. Perhaps the positive narrative we have constructed around light is the root of this inconspicuous pollutant. The overconsumption of light is leaving our world hurting, but we are too caught up in the glory of the blaze to take notice.
Light pollution directly affects us, negatively influencing our health, despite being the perpetrators of this spreading issue. Humans evolved from a time where days were regulated by the sun’s rise and set, internal clocks depending on both the light and dark portions of each day. However, sleep is no longer experienced within the confines of a completely dark bedroom. On any normal night, street lights glow through half-curtained windows, digital clocks blink brightly, and night-lights leave the room awash in soft light and shadows. While this scene may seem comfortingly ordinary, the illuminated bedroom is another form of light pollution, damaging the circadian sleep rhythms and reducing the quality of sleep. Our physical, mental, and behavioral changes follow a twenty-four hour cycle, called our circadian rhythms, and light pollution compromises this light-influenced system. Research has even found correlations between light polluted bedrooms and diseases, including higher risk for diabetes, obesity, and some cancers. The poison of light pollution in our bodies is not limited to nighttime, and can stem from numerous sources of light. Blue light is another main contributor, processed by receptors in the human eye effectively blocking melatonin production, a crucial hormone necessary for a good night’s rest. World-wide digitalization has acted as a catalyst for blue light issues, with exposure becoming the root of many sleepless nights. Light pollution is altering our natural rhythms and bodily functions, a poison that often slips by unrecognized.
Light pollution does not only affect those who are responsible for its drastic increase, infecting wildlife’s natural rhythms in the process. Animal behaviors are being threatened by light pollution, compromising migration patterns, habitat construction, and sleep cycles. Insect populations are severely declining, due to the sheer amount of bugs being incinerated by artificial lights, an alluring brightness that ultimately leads to their demise. The reduction of this crucial component in the food chain is continuing to affect the health and stability of animal populations that rely on this food source. Furthermore, the increase of urbanization and light usage is sending birds astray during migration flights, altering the sleep cycles of city birds due to excessive lights.
The reach of light pollution isn’t solely land-bound; light pollution has found its way into the ocean. The lights from oil rigs, harbors, boats, and ships are influencing the places marine life chooses to inhabit. Sea turtle numbers have seen a rise in fatalities due to the decreased visibility of the moon, which acts as navigation during migration. All things considered, light pollution is a pervasive issue spreading rapidly from land to sea.
Light pollution has been established as a global problem, but how do we switch its current trajectory, steering our light-dependent world back on course? While the ways we can make efforts in our daily lives might seem insignificant in the grand scheme, we must keep in mind that simply being conscious of these issues is a meaningful step in the right direction. Actions as easy as turning off the lights, or using fewer lights, in your household can begin reducing the impacts of light pollution. Close your curtains to block inside lights from seeping out of the confines of your home, and keep them shut as you’re falling asleep to support a better rest. When using your devices, whether it’s a phone or computer, try turning the brightness down or switching to night mode. These electronics have “the potential to contribute just as much (or more) light pollution than regular room light”(Moxie). This will also reduce eye strain and limit the amount of blue light expelled from the screen. Furthermore, a minor but consequential change would be to only use lights that face downwards, limiting the main contributors towards the star-concealing sky glow.
The next time you are heading upstairs to go to sleep, be increasingly mindful of turning off the lights and devices throughout your house. Close your curtains tightly, and if possible, turn off any excess lights in your room. You aren’t just practicing better sleeping habits; you are preserving your own health and protecting the lives of animals whom rely on the dark and stars to live. Our existence and interactions with the natural environment have an overwhelmingly negative influence on nature. Light pollution is a fraction of what we have inflicted on our environment, and everyone must work that much harder to recover what has been lost. It’s the hope that, on our journey towards rediscovering the stars, we’ll find a cleaner, healthier Earth along the way.
Bibliography:
Dutfield, Scott. “Light Pollution: Environmental Impact, Health Risks and Facts.” LiveScience, Purch, 5 Apr. 2022, www.livescience.com/light-pollution.
James Madison University. “Light Pollution: The Overuse & Misuse of Artificial Light at Night.” JMU, 4 Jan. 2022, www.jmu.edu/planetarium/light-pollution.shtml.
National Geographic. “Light Pollution.” Education, education.nationalgeographic.org/resource/light-pollution/. Accessed 6 Sept. 2023.
Staff, DarkSky Staff. “Light Pollution Affects Human Health.” DarkSky International, darksky.org/resources/what-is-light-pollution/effects/human-health/. Accessed 6 Sept. 2023.
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