Light: A Toxin

When we think of the word “pollution,” what’s the first thing that pops into your mind? Maybe it’s the contaminated waterways all around the world that are littered with plastic and debris suspended in a brown sludge. Or maybe it’s the grey plumes of noxious exhaust emanating from the factories that produce the annual ten million plus tons of textile. Or maybe it’s the orange-grey hellscape California is stuck with for at least a month every year due to “many, many years of leaves and broken trees” that are “like, so flammable, you touch them and it goes up.” Regardless, we all know that pollution isn’t that great of a thing. After all, it poses health hazards to humans and wildlife, destroys the habitats of countless fish and birds, and contributes to climate change and global warming, among other things.

When I think of the word “pollution,” my mind also immediately jumps to the tragic scenes of water and air pollution. However, the image of a dark canvas with an eerie, reddish glow also comes to my mind: the night sky.

Just a hundred years ago, the night sky was scattered with gleaming stars and a clear view of the milky way was visible. Obviously, this sight is still visible in some portions of the country and around the world. However, these areas are shrinking with the increased adoption of artificial lighting, leading to light pollution and the unsettling sight of a red night sky I described above.

Light pollution is the inappropriate or excessive use of artificial lighting.

Light pollution consists of glare (excessive brightness), skyglow (brightening of the sky), light trespass (unnecessary lighting), and clutter (disorienting lighting).

Street lighting is a contributor to light pollution. Only a small area that the light emanating from a light pole casts on the ground is useful, posing issues on efficient energy usage. The excessive light causes glare and contributes to light trespassing. Furthermore, light reflects off the ground, leading to the hazy glow of the night sky many urban centers experience.

Light pollution isn’t just about discomfort and energy usage. It also affects the behavior of wildlife and animals, as artificial lighting disrupts the day-night cycle present in animals. Furthermore, many animals rely on detecting light as a way to survive or reproduce. For example, the nocturnal reproductive behavior of amphibians like toads and frogs can be disrupted by artificial lighting.

Another example that is, arguably, more tragic is the death of baby sea turtles. When sea turtles hatch at night on the sandy beaches of Florida, they rely on detecting light on the horizon in order to reach the safety of the ocean. Artificial light from cities and elsewhere in the mainland lures baby turtles away from the ocean and, ultimately, to their deaths.

And as if baby turtles dying wasn’t enough, we all know that ecosystems are deeply interconnected and a change in one population can cause cascading effects with catastrophic consequences.

But there’s still hope. Obviously, we rely on artificial lighting in almost all aspects of our lives so we can’t just get rid of all lights. However, more conscious and mindful light designs have been and are being developed, reducing the effects of glare and more efficiently using energy. Furthermore, minimizing the usage of unnecessary artificial lighting at our own homes can be done by installing motion activated lights that will only turn on when needed.

Another thing we can do to combat light pollution is to help measure light pollution in our cities. Globe at Night is a citizen science campaign that allows for people to gain a better understanding of this issue and can be done with just a smartphone, tablet, or computer. Cities at Night is another great opportunity that combats light pollution. The International Dark-Sky Association is a great resource for more information on this subject.