What you can do to reduce light pollution

As the old saying goes, multiple hands can do light work. They can also work together to make the light disappear.

Urban light pollution is a large-scale problem, but individual households can help their communities dim the lumens while ensuring safety.

Nancy Clanton, managing director of lighting engineering firm Clanton & Associates in Boulder, Colorado, is passionate about sustainable lighting. She is a technical committee member of the International Dark-Sky Assn., and she offered this advice for reducing light pollution in your neighborhood:

Install time and motion sensors

The best way to reduce light pollution is to turn off lights completely when they are not needed. It will also save you money on your energy bill.

Motion sensors are a great way to control lights so they only come on when there’s action nearby. Go to sleep? Set a night timer. The birds and your neighbors will both appreciate it.

Use dimmable bulbs

Dimmable light bulbs have switches that control the intensity of the light they emit. This way you can only use them at their brightest setting when necessary.

Make sure your dimmer and bulb are compatible to avoid flickering, which can be a nuisance to humans and animals.

Choose warmer colors

Light bulbs with warmer or more yellow tones are more suited to our circadian rhythm than more blue light, which is why the “night” mode of your smartphone uses them.

Tone is measured by the color temperature of a lamp. Avoid “daylight” light and blue tones that have temperatures above 6000 degrees Kelvin. Choose bulbs with temperatures below 3000K instead.

Shield all external lights

A security light by the door does not need to illuminate a tree. Install a screen nearby that blocks any light escaping to the sky and redirects the beam entirely to the ground.

The shielding also allows the use of lamps that consume less energy to provide the same amount of light where it is needed.