dark sky lighting

Artificial light disrupts the world’s ecosystems. Dark Sky Lighting can help.

Light pollution is a serious issue. To refresh your memory, reread ASE’s 2011 article. Were you anywhere this summer where the sky was really dark and the moon and stars clearly visible? If so, you were in an increasingly rare place, removed from light pollution.

Light pollution is the excessive use of artificial light that is having dangerous environmental consequences for humans, wildlife and our climate. Would you believe that there are millions of children who will never be able to see the Milky Way where they live? For three billion years, life on Earth had an uninterrupted rhythm of light and dark created by the sun’s orbit. The rhythm is encoded in the DNA of all plants and animals. It governs behaviors like reproduction, feeding, sleep and safety from predators. The light pollution that is canceling out the darkness is shifting our environmental balance.

Some examples of the harm being done by light pollution:

  • Sea turtles hatch their babies at night on beaches. Artificial lights draw them away from the ocean. In Florida alone, millions of hatchlings die every year because of this.
  • Birds that hunt or migrate at night navigate by moon and starlight. Artificial light can interfere with that navigation and get them off course. Millions of birds die every year by colliding with buildings and towers that are lit up. Artificial light also causes birds to migrate too early or too late.
  • Nocturnal animals that sleep during the day and are active at night are having their habits confused by the illumination of the night.
  • Artificial light at night can throw off the ability of plants and trees to adjust to seasonal changes. This in turn (because everything is connected) upsets the wildlife that depends on the trees for their habitats.
  • Many humans are developing sleep disruption because the night never gets truly dark due to artificial light. Blue-rich light at night is the most harmful for humans. Blue-rich light comes from our TVs, LEDs used for outdoor lighting, computer screens and other electronic devices.
  • Coral reef spawning is dependent on moonlight and artificial light is interfering with moonlight and preventing the spawning.

Much of the outdoor lighting in use today is inefficient, overly bright, unnecessary and poorly placed. This light is often wasted by being directed into the sky instead of being focused on the actual objects and areas that people need illuminated.

A 2016 world-wide study by the journal Science Advances found that over 80% of the world’s population lives under light polluted skies. The U.S. and Europe have the most nightly ‘skyglow’ with 99% of their residents living with it.

The good news is that light pollution is reversible, unlike many other forms of pollution. There are ways we can still use outdoor light, but in a way that is safer for our environment. Use of night lighting for increased safety and visibility is necessary and encouraged. There is a type of outdoor lighting which is much safer for our environment and is being supported by environmental groups. It is called Dark Sky Lighting. It is outdoor lighting that casts light downward, giving more light to what you need to see and not wasting light into the night. Dark sky lighting also leaks little or no light from the fixtures.

Here are some steps we all can take to reduce light pollution:

  • Using motion sensors around your house is the most environmentally friendly option – your path lighters come on when they sense motion and turn off again when the area is still.
  • Turn off your porch light when you go to bed.
  • Use light timers that come on when it gets dark and turn off when you go to bed.
  • Use low-glare outdoor light fixtures. A company called Starry Lights specializes in low-pollution lighting.
  • Use energy efficient LED light bulbs. They provide more direct light and use fewer lumens to get emitted into the night sky.
  • Use lighting fixtures with the International Dark Sky Association’s Fixture Seal of Approval.
  • Check out this chart of acceptable and unacceptable lighting fixtures – see below or click here.
  • Home Depot carries many brands of Dark Sky lighting.


Check out this interactive map that allows you to look up your address and see the grades for light pollution. Scroll down to ‘view map legend’. I found the results difficult to understand, but that’s probably just me!

Note:  In 2001 the International Dark Sky Association (IDA) established its Dark Sky Places program to encourage different regions around the world to find ways to protect areas from light pollution. The IDA receives proposals for particular sites worldwide, and works with local representatives to assist the areas in protecting their night skies, and then gaining official status.  Since 2001 there are now 67 Dark Sky Places around the world.  Asia is the most recent area to enter the program.

*2017 – This year’s International Dark Sky’s Week celebrations begin Saturday, April 22 Earth Day!), and run through Friday, April 28 (click here for resources to use during the week).