What is light pollution?

Light pollution is the inappropriate use of artificial light at night.

“Light pollution is an environmental pollutant that harms our planet and robs us of the opportunity to experience the wonder of a natural night sky.” (IDA, 2020)

Photo above – Light pollution is visible from space.

Sources of light pollution

Its sources include building exterior and interior lighting, advertising, commercial properties, offices, factories, streetlights, and illuminated sporting venues. Much outdoor lighting used at night is inefficient, overly bright, poorly targeted, improperly shielded, and, in many cases, completely unnecessary. This light, and the electricity used to create it, is being wasted by spilling it into the sky, rather than focusing it on to the actual objects and areas that people want illuminated. 

The inappropriate or excessive use of artificial light – known as light pollution – can have serious environmental consequences for humans, wildlife, and our climate.  

Components of light pollution include: 

  • Clutter – bright, confusing and excessive groupings of light sources.
  • Light trespass – light falling where it is not intended or needed.
  • Skyglow – brightening of the night sky over inhabited areas. 
  • Glare – excessive brightness that causes visual discomfort.