Why Light Pollution?

Light Pollution's Effects on Astronomy

Light pollution affects all levels of astronomy. Many children and those without advanced equipment are no longer able to see the stars in the night sky due to the "skyglow" created by artificial light. 

One study estimates that 80 percent of Americans are no longer able to see the Milky Way. 

Light pollution has restricted the general public's ability to see the stars, hiding the night sky from children and no longer sparking the curiosity that it once did.

Light pollution also restricts the ability of scientific study of astronomy. 

Modern astronomical research facilities are forced to be in remote locations to avoid light pollution. This causes the logistics of this research to be more complex and more costly; light pollution also hinders our species' ability to understand the universe around ourselves.

In addition, brighter backgrounds in the sky overall leads to reduced data quality gloally. Higher background noise levels makes the perception of dimmer objects much more difficult. Being able to see dim objects is crucial to astronomy. Some examples are planets orbiting bright stars, very distant objects, and weak gravitational lensing to study dark matter.

The overabundance of light on Earth has led astronomers to launch telescopes based off-planet, like the recent James Webb Space Telescope. Launching these telescopes are costly endeavors, which might not be necessary if we could rely on astronomical observation on Earth. 

Many species have evolved to use cues from natural light for navigation. However, the presence of light pollution has disrupted these natural instincts. 

Newborn sea turtles instinctively move toward the brightest horizon, which is usually the reflection of moonlight on the ocean under natural conditions. However, many hatchlings now travel towards beachfront lighting instead of the ocean, where they often die. Bright beaches also discourage adult turtles from laying eggs.

Birds can also become disoriented by bright city lights, causing them to crash into city buildigs.

Insects that are commonly attracted to lights are often killed by humans, leading to population decline.

These are just some of the many impacts of light pollution on the environment.

Impacts on Humans

Your body's internal clock, or circadian rhythm, helps you identify whether it's day or night and tells your body when it should be sleeping. However, bright lights at night can distrupt your circadian rhythm and confuse your body. This leads to poor sleep, especially in people that prefer dark settings to sleep.

More lights also leads to more heat generation, making indoor settings hotter and increasing our reliance on air conditioning. Excessive use of air conditioning leads to outdoor temperatures becoming hotter as they push hot air out of your house, enforcing a postive feedback loop of articial cooling that not only wastes energy but also harms the environment.

And obviously, environmental impacts like climate change and global warming lead to consequences for people around the globe.

Light Pollution Mitigation

Although light pollution is a large issue, there are many ways that we can help reduce its effects.

Much of the issue of light pollution is that there are simply too many lights perpetually illuminated in cities. However, nighttime lighting is still a necessary part of our lives, even with the consequences of light pollution.

One important idea that primarily improves outdoor lighting, like street lights, is downward-directed lighting. Light pollution isn't caused by simply any light; it's light being able to escape and illuminate the sky that causes problems. By designing lights so that they illuminate the ground, which we need to see, but not the sky, downward-directed lighting reduces light pollution while still letting us see at night.

Local governments can create lighting ordinances to enforce light pollution-friendly practices, or create dark-sky preserves.

Something anyone can do to conserve energy and reduce light pollution is to turn off lights when they're not in use, or instal smart technology to automatically manage lighting. When buying new light fixtures, make sure that they're DarkSky approved.

Useful Readings and Links

Websites and articles that have additional important and useful information about light pollution.

Light pollution - Wikipedia 

What is light pollution? | DarkSky International 

Light Pollution - Night Skies (U.S. National Park Service) 

Solutions to light pollution | DarkSky International 

10 Simple Ways to Reduce Light Pollution | Visit Durango, CO | Official Tourism Site 

Light pollution harms wildlife and ecosystems | DarkSky International