Reducing Light Pollution in Urban Centers

The word “pollution” often makes people think of contaminated water, unclean air, or simply piles of trash in landfills and oceans. However, there’s another type of pollution that often goes overlooked, yet has harmful impacts on the environment as well as human health – light pollution. This type of pollution is so common in urban dwellings that most people don’t even notice it; but if you’ve ever walked outside and looked up at the night sky only to see a pervasive faint glow instead of countless stars, you’ve experienced light pollution.

3 Categories of Light Pollution

Light pollution is an unwanted consequence of outdoor lighting and is divided into three categories: sky glow, light trespass, and glare.

  1. Sky Glow: Artificial lights that are pointed upwards or misplaced cause the sky to “glow” unnaturally, blocking star visibility.
  2. Light Trespass: Light escaping into areas where it’s not wanted or needed.
  3. Glare: Bright, glaring light that reflects off of poorly built lamps.

Research into the health and environmental effects of light pollution is still in its early stages, but we already know enough to prove that light pollution needs to be mitigated. It interferes with the migratory and breeding patterns of wildlife, as well as with nighttime ecosystems. Unnecessary outdoor lighting wastes a lot of energy and contributes to greenhouse gas emissions.

Glare from bad lighting can be harmful to drivers because it causes disability glare. Constant exposure to artificial lighting has adverse effects on human health, such as reducing the production of melatonin, a hormone which affects sleep.

Light pollution comparison of streetlights. Image via Penny4NASA.

Light pollution comparison of streetlights. Image via Penny4NASA.

How to Reduce Light Pollution

On the other hand, well-planned lighting can actually decrease crime, cut energy costs, and most importantly, lessen light pollution. It’s both beneficial and important to show support for well-planned lighting on the city, state, and federal level. While you’re waiting for corporations and governments to get on board, however, here are some ways you can reduce light pollution as an individual.

1. Install Motion Sensor Lights

With these in place, lights would only come on as people and moving objects approach, therefore reducing the amount of wasted light or “light trespass” emitted from the street on average. If motion sensor lights were deployed across an entire city, the results would be remarkable.

2. Lower Bulb Wattage

Switching to low-wattage bulbs is a direct way of reducing light pollution. Look for lights that have a warm white illumination.

3. Replace Outdoor Lights with Smart Design, Low-Glare Fixtures

The International Dark-Sky Association assesses light fixtures for their glare and efficiency. Also, companies such as Starry Night Lights, specializes in lighting that cuts down on light pollution.

4. Ensure Bulbs are Covered and Light Emitted Faces Down

Street lights should feature a bulb with a hood, which enables light to be channeled down, reducing wasted light.

Working with communities and local governments to make changes like these would do a world of good, and could bring a city one step closer to clearing the skies of unwanted light pollution. Let’s give way to the great stars of the night sky that lie beyond.

Featured Image: Light Pollution over the Rooftops of Toronto, Canada. Image via Freaktography.

Copyediting by Daniel Cordero

About The Author

is an undergraduate at Scripps College and working towards a bachelor’s degree in Environmental Analysis with a focus on sustainable urban development. In her spare time, she enjoys, camping and hiking throughout her home state of California. She plans on pursuing a career in sustainable development and consulting.