Today marks the first day of the International Dark Sky Week this year, designated for April 5-12, bringing the importance of dark skies into focus and trying to educate people about the importance of reducing light pollution.
While everyone knows and talks about air pollution, finally getting to the point where we (at least most of us) are all trying to reduce it, light pollution is another issue we need to deal with. Those of us who ever got involved in astronomy and stargazing at any level, always knew how annoying light pollution is when you try to watch the night sky. In recent years, however, the issue has become better known, thanks to the efforts of the International Dark Sky Association to bringing it to the forefront.
There are also ways we can all contribute to reducing light pollution and bringing awareness to it every day, and especially this week. Here are a few.
Learn About Light Pollution
We can all do our part in reducing air pollution, and even if we don’t think about it every day, this week we should learn about it, and why it is important to reduce it.
What Is Light Pollution and Why Is It Harmful?
It might not seem like it, but light pollution is harmful to the environment, disrupting not only wildlife, but having a negative effect on our own health, and even contributing to climate change. Using artificial lights might seem harmless, besides wasting electricity and obstructing our views of the celestial objects in the night sky. Those are only annoyances, more to some of us than to others. But what is less obvious is the effect it has on our surroundings, and you might find it as an exaggeration to say it contributes to climate change.
First off though, not every light you turn on contributes to light pollution is considered wasted light, artificial light that is not needed or is brighter than needed. For example, you can have a small porch light that casts the light down on your door that you only turn on when needed, instead a bright one that is always on and sheds its light upwards, where you don’t need it. In a nutshell, light pollution is unnecessary bright light.
The effect, especially in large cities, where commercial lighting is so prevalent, includes a light glow all night long that turns night into dusk. In the past years I noticed there is never fully dark in Phoenix. No matter when I go outside, it always seems to be dusk – even at 2 am on a moonless night. And as annoying as it is to me and my family, it comes with a much larger price.
Environmental Problems Caused by Light Pollution
Artificial light attracts and kills insects. Which might seem desirable; my first reaction would be, great, insects are such pests, I don’t want them around. However, this decline has negative consequences to all life. The decline on insects means less food for birds and bats, and other mammals that feed on them, so it contributes to the decline of their populations. Their decline also means fewer pollinators for all sorts of plants, which leads to less plant diversity. Which also affects agriculture, so it affects our food source and health.
Besides the lack of insects as food, light pollution is directly harmful to migratory birds. They usually fly at night, when the light from the stars and the moon help them navigate. Light pollution in larger cities is bad enough that they can’t see these celestial objects, and the artificial lights get them disoriented. According to the National Audubon Society, some collide with buildings, others “may circle in confusion until dawn, when they land – potentially without access to critical resources – and are subject to other urban threats.”
Light pollution affects sea turtles. Female sea turtles shy away from brightly lit areas, which disrupts their nesting patterns. Baby turtles on the other hand, normally hatch at night and would follow the glow from the moon to make their way to the water, and instead they follow bright city lights, going in the wrong direction and getting killed by either traffic in the street or simply not surviving since they get farther from the water.
Other reptiles and mammals are also affected by light pollution, especially nocturnal ones, as the bright lights disrupt their feeding and mating habits.
Unnecessary lighting contributes to carbon dioxide emission, which in turns contributes to global warming and climate change. Partially because light is generated by electricity, which is still mostly generated by fossil fuels, adding to general pollution.
But also, more directly, night time lighting affects our air quality, disrupting the naturally forming nitrate radicals that clean our air. While I don’t fully understand the process (although I read a few papers about it, chemistry has never been my strong subject), these nitrate radicals occur in the dark, so normally at night, and interact with the particles and pollutants in the air, getting rid of them, ultimately cleaning our air. Nighttime lighting doesn’t allow these nitrates enough dark to form, so they can’t help clean the air we pollute during the day.
And what most of us don’t realize is that light pollution directly affects our own health, by disrupting our sleep. When my kids were babies, I remember reading studies that sleeping with a night light might cause myopia (nearsightedness). But that’s just one of many health problems caused by exposure to night time artificial lights.
Researchers also say that being exposed to artificial lights at night disrupts our circadian rhythm and our production of melatonin. Melatonin helps keep us healthy by helping us sleep, boosting our immune system, lowering cholesterol. It also helps some of our most important glands, like the thyroid, pancreas, adrenal glands, among others, function properly. Nighttime exposure to artificial light suppresses melatonin production, causing all sorts of health problems.
Help Reduce Light Pollution
While cities and big corporations are responsible for most light pollution, and changing things at that level might not be so easy, each of us can contribute to reducing light pollution, to bringing back the dark skies. Also, the good news is that thanks to organizations like the IDA, more and more cities are aware of the problem, and take steps to change things.
When they introduced the International Dark Sky Places conservation program in 2001, they started designating International Dark Sky Communities and Urban Places among dark sky parks, reserves and sanctuaries. This, in turn, offers communities incentives to reduce light pollution in urban areas, besides keeping the skies dark outside of the cities. We have many designated dark sky places in Arizona, for example.
We can all contribute by using the same principles the dark sky communities use.
Only use lighting when and where you need it
This doesn’t necessarily mean you should keep your house in dark as soon as the sun goes down. Our lifestyle changed to the point where we stay up hours after the sun goes down, and we do need artificial lights. But it is easy enough to only turn on lights in the rooms we are using, and turn them off as soon as we leave.
Our porch lights don’t need to be on all the time; if safety is a concern, most lights now are equipped with motion detectors, use those. Also, not all porch lights are created equal.
Use a porch light that only illuminates the area it needs to
Porch lights may scatter light in all directions, adding greatly to light pollution, which is not needed. You can find outdoor light fixtures with shields directing the light downward, exactly where needed, at your porch.
Keep your blinds drawn to keep light inside
You might need lights inside, but you don’t need to illuminate your street or back yard from your room. Besides, if you’d turn the lights on and your blings are open, anyone who passes by can see you. So this measure is as much for privacy as for keeping light pollution from your street.
Minimize blue light
You wouldn’t think it does, but the color of light matters. Blue light brightens the sky more than any other color light, so it is important to choose a different color. According to researchers from Harvard Medical School, blue light is the most harmful for human health, so this measure helps us, too.
The IDA recommends measures to “minimize harm from blue light in your home, choose the right light bulb and download a color temperature app that adapts your electronic screen to the time of day – cool light during the day and warm light at night.”
Color temperature apps that change the light color of screens to eliminate blue light are available for all devices now, while some of the newest devices already have them preloaded, you just need to set them up.
Teach Others About the Importance of Dark Skies
As we learn about the importance of dark skies and reducing light pollution, we should try to tell our friends, families, coworkers, acquaintances about it. Many people don’t know or don’t understand the importance of dark skies for our health and our environment. By talking about it, pointing them to the right places to learn about the issue, we can spread the word.
Unlike most other pollution and environmental problems, light pollution is relatively easy (or easier) to fix. All it really takes is awareness.
If you have a telescope, set it up in your neighborhood at times, and let your neighbors look through it. Use the event to ask them to turn off the outdoor lights, and talk about the importance of dark skies with them.
If you are a member of an astronomy club, you are already helping during every star party, so Thank you! If you are interested, you can find an astronomy club for amateurs in every city to join.
Stay Overnight at an International Dark Sky Park or Sanctuary and Enjoy Stargazing
For the fun part, find a dark sky park or other dark sky place, away from city lights, camp out and watch an incredible show after the sun – and the moon sets. Enjoy watching the Milky Way and all the celestial objects as you can probably never see it in your own back yard (unless you live far from any communities).
