Why Light Pollution Matters and How You Can Help Minimize It [Week 15]
Amanda Drews, 10 minute read
Light pollution may not seem like a big deal at first, but it can have some major effects.
- What is light pollution?
- Why is it harmful for people?
- Why is it harmful for wildlife?
- What can you do to help minimize light pollution?
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What is light pollution?
You’ve seen the obvious effects of other types of pollution. Smog over a city causing breathing issues, a beached whale with trash found in it’s stomach, undrinkable water from contamination. But what exactly is light pollution? The simple answer is that it’s too much light shining at night.
National Geographic also calls it photopollution. It’s typically urban areas where you get light pollution since there are higher concentrations of people living there. Small amounts of light aren’t harmful but when you add them all up, it makes a big difference.
Think about flying in an airplane at night. If you’re high up enough, you probably won’t see one house light left on. But if everyone in that community keeps one light on at night, the whole town will be lit up from the sky. Light becomes pollution when there is an excess amount of unnecessary lighting being kept on at night or the light is being distributed the wrong way.
Why is it harmful for people?
Lights are an important safety feature for communities. A big harm for us is the energy use from excess lighting. Not only the global warming potential and resource use but the monetary costs associated with it. Why pay for it if you don’t need to keep a light on at night?
Lights can have adverse health effects on people.
Extremely bright lights with high glare, think Friday night football games, can do damage to your retinas. Even the lights around your home can effect your health. Clevelandclinic.org points out that while LED bulbs are more energy efficient and cost effective, they emit more harmful short-wave, blue light. Assess the light bulbs around your home and find a happy medium between energy efficiency lighting in areas that you don’t hang out in at night and low-emitting bulbs in your night time hangout spots.
Assess the light bulbs around your home and find a happy medium between energy efficiency lighting in areas that you don’t hang out in at night and low-emitting bulbs in your night time hangout spots.
In a normal circadian rhythm, according to sleepfoundation.org, our brain’s pineal gland starts producing melatonin when it starts to get darker at night. That melatonin is the hormone that helps you get drowsy. When those light cycles are interrupted, people can lose out on sleep which, as any parent of a newborn could tell you, messes up everything!
Being exposed to lights can also reduce the quality of the sleep you are able to get if you are waking frequently and aren’t able to make it into deep, restorative stages of sleep. If you do leave your lights on at night, consider your neighbors and if your lights will be shining into their bedroom windows. This can be a big issue for people living in the middle of a city or around businesses as well.
Who doesn’t like looking up at a clear night sky full of stars? In urban areas, it’s much harder to see those stars because of light pollution and it reduces our ability to enjoy the night sky. There are people living in cities around the world that may never see the Milky Way. Light pollution also hinders scientists that are studying the atmosphere.
Why is it harmful for wildlife?
For many animals that are active at night, light pollution can severely disrupt their natural patterns of hunting, avoiding predators, mating, and migration. Think about an animal that is hunting at night. All those years of evolving to be an efficient night predator and all of a sudden, BAM! we invent electricity and now their prey can clearly see them! Frog calls at night, a mating ritual, can be interrupted by artificial light and have the potential to decrease breeding success (Baker and Richardson, 2006). Same goes for the flashing lights of fireflies (firefly.org.) We are interrupting the sexy vibes they are trying to send out!
Some of the most striking effects light pollution has on animals can be seen with sea turtles and birds. Sea Turtle Conservancy states that lights discourage female turtles from nesting in spots that will be safe for their eggs. When the hatchlings emerge from the nests, they are normally guided back to the ocean by the light reflecting off the water from the moon and stars. The light pollution coming from shore can send the baby turtles in the wrong direction and lead to higher hatchling mortality.
Scientists still don’t completely understand why birds are attracted towards artificial lights in the dark. Buildings covered in windows with lights on at night are very dangerous for birds. According to Audubon.org there are specific types of birds that are most likely to fly into those buildings. Ones that vocalize while flying at night such as dark-eyed juncos, white-throated sparrows, ovenbirds and song sparrows, have higher strike rates than quiet flyers.
Photo credit-Debbie Reynolds 
Photo Credit- Debbie Reynolds
Click here to check out my past post on how to prevent window strikes from birds on your home
While scientists believe birds may use a combination of landmarks, the sunset, Earth’s magnetic compass, and the stars (according allaboutbirds.org), having artificial light can throw them off from the direction they are supposed to be heading in during migration.
What can you do to help minimize light pollution?
Through A Greener Demeanor’s Waste 101 series, we’ve learned how to tackle and minimize the physical waste we create, so here’s how you can help with light pollution.
1. Turn off your lights at night if you don’t need them on.
Keep your lights off at night if you can safely do so. Or don’t turn them on in the first place unless you need to. This will save you on your energy bill!
3. When you have lights on inside your house at night, close curtains or blinds to keep the light in. Only turn lights on in the room you are using.
I’m the kind of person who likes every light on in the house for any room that I might be using in the next few hours. It’s a terrible habit that I need to work on but I just like to see what’s going on around the corner, especially if I’m at home alone! Challenge yourself or your family to only have lights on in the room they are currently in. While you’re in that room, keep the blinds or curtains closed. Not only will that help keep the light in but will prevent creepers from peeking in if they walk by at night!
4. If you are in need of new outdoor lighting, consider IDA approved lighting.
The IDA’s Fixture Seal of Approval program gives a third-party certification for lights that “minimize glare, reduce light trespass, and don’t pollute the night sky.” They have a database to help you find lighting that meets their requirements of having a CCT (Correlated Color Temperature) of under 3,000 for lightbulbs and the appropriate shape of the light shield so light is directed downward. This will give you eco-friendly lighting for your home.
However, if you aren’t seeing an IDA approved light that matches your style or budget, look for something that is under 3,000 CCT or K (for Kelvin) and shines the light down. The ones we ended up picking out for our home do shine a bit out to the sides but the glass is textured so it stops it a little bit more than if it were clear.
Below are some that I don’t have but might be a little closer to IDA standards versus your typical lighting.
2. Consider putting your outdoor lights on timers or motion detectors.
This can be a good alternative to just turning them off. This way, if something does move in front of your sensor, the lights will turn on. Or with a timer, you won’t have to think about turning them off at night if you did recently turn them on. This is a good compromise for keeping your house safe, minimizing light pollution and saving a bit of money.
There are more options for brightly lit motion sensor lights than there are IDA approved ones. I don’t see this as a huge issue though if they only turn on from motion and are only lit up for a few minutes a night, if at all. We like our MPOW solar powered light on the right.
Here are some other downward facing motion sensor lights with options for a 3000 K bulb:
5. Participate in research as a citizen scientist!
With an increase in accessible technology, researchers have taken to asking for citizens all over the world to help with all sorts of large scale projects. By participating in citizen scientist projects, not only will you learn a great deal but you will be helping to contribute to actual scientific research. Have your kids participate so they can learn the importance of contributing to science. Each project will give you the training you need, even if you have no background knowledge or experience.
Here are some light pollution citizen scientist projects you can participate in:
- Globe at Night– a National Science Foundation’s NOIRLab program. They ask you to try and locate a specific constellation each month, record sky conditions, and if you have a sky quality meter app on your phone, to measure the brightness using your phone’s camera.
- Cities at Night– help sort and identify photos taken from the International Space Station through NASA. They need people to help them create a map of the world at night as seen from space.
6. Urge your community leaders to install or replace municipal lighting with dark sky compliant lights.
Speak up for the town you live in! Whether you are on a panel, board, or a citizen, you can make a difference in your community. See if you can find your city’s municipal code and their policies on light pollution. Write, email or call your city’s decision makers and tell them your concerns about light pollution. Hold an event within the community to gain support.
Citiesatnight.org has a handy guide for decision makers on city councils for choosing the best lighting. They should debate on if a light is needed in that location in the first place. Then they should aim for minimal lumens, amber lights vs blue lights, and develop strategies on the timing and direction of the lights. High pressure sodium lights are a favorite for city lamps because the energy emitted is mostly amber.
There are tradeoffs that you will have to work through in order to pick the best light for a situation.
At this point you might be thinking, “Wait, aren’t LEDs supposed to be more eco-friendly because they are more energy efficient?” You would be right. IDA offers a Practical Guide for choosing lighting. There are some tradeoffs considering that LEDs are more energy efficient, can be safer and can light up a larger area per light.
While you are choosing lighting for your home just remember to keep in mind when you are in an area of your home and what tasks are completed there.. This guide goes through some great steps on how to balance out energy efficiency and dark sky friendly lighting.
- Write to and encourage your community leaders to put in IDA friendly lighting around your town.
- Take a walk around your house and assess your indoor and outdoor lights. Do you keep them on at night? Do you have to? What kind of bulbs are you using? Which direction does the light go? Could you put in motion detectors or put them on timers?
- Look at your inside window treatments. Consider installing blinds or curtains in rooms you may have lights on in during the night.
- Become a citizen scientist! Check out some options on Darksky.org.
- Put International Dark Sky Week in you April calendar and celebrate it, talk about it or share on social media.
- If you are in the market for lighting, take a look at IDA friendly or similar options.
- Move on to Week 16 to learn about Reusing and Up-cycling.
