What is Light Pollution?

See below for a list of common terms regarding light pollution. In short, light pollution is any improper use of exterior lighting that can degrade the quality of the surrounding environment.

What is Light Pollution caused by?

The cause of light pollution is artificial light at night, be it from street lights, parking lot lights, front porch lights and countless other outdoor light sources. See ‘What is Light Pollution?’

What are the common forms of Light Pollution?

The four types of light pollution include glare, skyglow, light trespass, and clutter. See ‘What is Light Pollution?‘

What are the effects of light pollution?

Recent research indicates that light pollution can adversely affect human health and ecosystems while also wasting energy, interfering with astronomical research, and artificially brightens the night sky to create a condition known as sky glow.

How far does light pollution reach?

Light pollution travels quite a bit. It’s what makes light pollution so ubiquitous. Light pollution commonly can extend upwards of 20-30 miles from the source.

What is the biggest source of light pollution?

Any light that emits light upwards or sideways can create light pollution, this includes any light fixture angled below 90 degrees to its mounting.

How can we get rid of light pollution?

Light pollution may be the easiest pollution to fix, as it simply requires the user to operate the light in a responsible manner. However, like water pollution, which suffers from multiple nonpoint sources of contamination, light pollution often suffers from multiple irresponsibly and over powered lighting sources.

To help reduce lighting, use light only when and where it’s needed. Use motion sensors or timers. Utilize shielding or aim your lights directly downward (not outward). See ‘What is Light Pollution?‘

How does light pollution affect sleep?

Light pollution disrupts circadian rhythms and the production of melatonin, which can produce health related concerns. Light pollution affects sleep by decreasing the amount of time spent during the REM (rapid eye movement) phase of sleep which is the most restful and restorative phase of sleep. See ‘What is Light Pollution?‘

Common Definitions

Light Trespass: When unshielded lighting shines where it is not wanted or needed. Light trespass can result in neighbor disputes. Sometimes called nuisance lighting.

Light Pollution: The improper use of exterior lighting that negatively affects the surrounding environment. Light pollution may artificially brighten the night time sky, reducing star visibility and creating exceedingly bright cloudy nights. Such impacts can alter wildlife breeding and hunting habits, and potentially negatively affect human health.

Glare: Any excessively bright light source that causes visual discomfort or temporary blinding to the surrounding environment.

Sky Glow: The brightening of the nighttime sky due to artificial light sources.