Light Pollution and What We Can Do About It

Title image of light pollution. Streetlights giving off excess lights on a city street.


As the weather gets nicer, more activities get held outdoors. Some of those activities may go on until well after dark. 

Many parks have lighting systems to accommodate those that prefer evening recreation. But what impact are those lights having on the local area?

The modern world has changed how we see the landscape above. According to DarkSky, less than 100 years ago, everyone could see a fantastic sky filled with countless stars. Now, millions of people will never experience seeing the Milky Way because of light pollution.  

But light pollution doesn’t just impact stargazers.

Let’s look at light pollution, its effects, and what agencies can do to reduce it.

What is Light Pollution?

image of light pollution sky glow


Light pollution is an excess of outdoor light at night created by artificial sources. It is mainly caused by bad lighting designs that allow light to shine outward and upward instead of focusing downward.

It’s a type of pollution that doesn’t get talked about much but impacts vast sections of the world. According to an article by the National Park Service, 80% of the world’s population cannot see the Milky Way in their backyard. All because of community light pollution.

Light pollution falls into a few different categories, including:

  • Light Trespass: When light reaches an unwanted place. For example, when tennis court lights bleed into a neighbor's backyard.
  • Skyglow: Combined illumination of all sources, creating an artificially bright arch over an area. You could often see skyglow when approaching an urban area at night.
  • Glare: Excessively bright lights that cause distraction or discomfort. For example, poorly aimed ballfield lights make it difficult for an outfielder to catch a fly ball. 
  • Light Clutter: Excessive grouping of lights bunched together that cause visual confusion. This could be like a row of lights on a pathway that doesn’t have light properly directed downward.
  • Over-Illumination: Using too much light in a particular area makes it much brighter than needed. For example, a brightly lit parking lot that rarely gets used at night. 


The Effects of Light Pollution

Light pollution is more than being unable to see the stars. The adverse effects of too much artificial light impact our health and the environment. 

Human Health Impact

Our bodies need darkness. Too much artificial light can affect our circadian rhythm--that instinctual pattern that tells us when to sleep and wake up.

Poor sleep quality has been linked to many chronic, potentially fatal health conditions like diabetes, cancer, heart disease, and mood disorders.

Environmental Impact

Some animals depend on the darkness. It’s how they migrate, reproduce, or find food. Too much light affects their behavior.

For example, lights from cities attract birds. The light throws them off course or causes them to run into lighted buildings.

Even plants can be affected by light pollution. Plants use sunlight to create energy and oxygen. Artificial light can change their natural cycles, shortening recovery periods after growth spurts or flowering. Some plants may start flowering sooner, disrupting the natural flow the local ecosystem develops.

Don’t We Need Outdoor Lighting For Safe Patrons and Facilities?

Our current behavioral patterns require some outdoor lighting. Playing a softball game in complete darkness wouldn’t be considered safe. Illuminated paths allow individuals to take evening strolls or jogs. And lighting around our facilities can alert us to any intruders or vandals.

So, yes, there are times when outdoor light is beneficial.

But it’s even more beneficial and economical when the light gets used mindfully and conscientiously.

What We Could Do About Light Pollution

Here’s the good news…light pollution is reversible. Get rid of the source of light, and it’s dark again. Have you ever been outside when there was a power outage? You see what a difference that makes.

Now we can’t cut the power in our communities as the sun starts going down. But there are some things we can do at our parks and facilities to help make the nights a little darker so everyone benefits.

Here are some things parks and recreation agencies can do to help reduce light pollution.

Assess the Areas that Need Light

There will be areas where light is essential--like leading down a stairway or at a ballfield with frequent night games. In other areas, artificial lighting isn’t as necessary. 

rt by determining where light is needed in your parks and facilities. From there, you can work on the next steps.

Asses Your Lighting Fixtures

Where does the light go when the fixtures of your parks and facilities are on? Ideally, the light should get shielded and directed downward. Reduce as much upward light as possible. 

Opt for warm-colored lights with a reduced blue spectrum. White and blue lights affect wildlife more than warmer colors. 

Determine the least amount of wattage needed to provide adequate lighting. Dimmable light fixtures allow adjustable illumination in areas. You can also look for fixtures approved to control light pollution--such as products that get the DarkSky Fixture Seal of Approval.

Adopt Lighting Management Strategies

For areas where light is necessary, determine when these spots are used most often. Are there ways to incorporate timers, motion sensors, or dimmers into the fixtures? Are there ways to ensure non-essential lights are turned off when not in use?

Inspect and Maintain Light Fixtures

Another way to help reduce light pollution is maintaining your fixtures. Wind, storms, and pole damage can knock lighting out of alignment, leading to uneven or misdirected light.

Learn more about outdoor lighting maintenance tasks in one of our previous articles. 

Educate Park Visitors and the Public

Many people don’t know about or understand light pollution. By raising awareness about the impacts of light pollution and how to reduce it, park visitors are more understanding when old fixtures get switched out, or a parking lot may not seem as bright as before.

The Takeaway

Light pollution is an often overlooked and misunderstood problem affecting our communities and ecosystems. There is good news; once we make the effort to reduce light pollution, we start noticing a difference very quickly. 

Choosing equipment and adopting strategies to reduce light pollution allows parks agencies to be examples for reducing excess artificial light in the community.