What’s Light pollution?
What Is Light Pollution?
Light pollution occurs when we over-light our surroundings, fail to use timers or sensors, or use the wrong color of light. These practices create unnatural lighting conditions that disrupt ecosystems and affect many species, including migratory birds, pollinators, sea turtles, mammals, and humans.
While most of us are familiar with pollutants like chemicals in our air and water, it may come as a surprise that light can also act as a pollutant. Excessive artificial light disrupts the natural darkness of the night, which many species rely on for survival.
The Components of Light Pollution
Light pollution can be broken into several distinct components:
Glare: Excessive brightness that causes visual discomfort, often making it difficult to see at night.
Sky Glow: The brightening of the night sky over populated areas, which obscures stars and celestial objects.
Light Trespass: Light that falls where it is neither intended nor needed, such as a streetlight illuminating your bedroom window.
Clutter: Bright, confusing, and excessive groupings of light sources, such as in commercial districts or sports venues.
What Causes Light Pollution?
Light pollution is a byproduct of industrial civilization. Its primary sources include:
Building exterior and interior lighting
Advertising and illuminated signage
Commercial and industrial properties
Offices and factories
Streetlights
Sports and entertainment venues
The widespread use of artificial lighting, while beneficial in some contexts, often comes without consideration for its environmental and health impacts.
Photo taken in the Everglades National Park from 30 miles away from the closest city.
How Bad Is Light Pollution?
Light pollution is an international concern, with much of the Earth’s population living under light-polluted skies. If you live in an urban or suburban area, you can observe this pollution firsthand by looking up at the night sky. How many stars can you see?
According to the 2016 groundbreaking “World Atlas of Artificial Night Sky Brightness,” 80 percent of the world’s population lives under sky glow. In the United States and Europe, 99 percent of the public can no longer experience a natural night sky.
To assess light pollution in your area, you can use interactive tools like the Globe at Night map or the NASA Blue Marble Navigator to view artificial lighting from a global perspective.
The Effects of Light Pollution
A growing body of evidence links the brightening night sky directly to measurable negative impacts in several areas:
Wildlife and Ecosystems: Many species depend on natural darkness for navigation, reproduction, and predator avoidance. For example, sea turtles rely on moonlight to guide hatchlings to the ocean, but artificial lights can lead them astray.
Human Health: Exposure to artificial light at night can disrupt circadian rhythms, contributing to sleep disorders and other health issues.
Energy and Climate Change: Inefficient lighting wastes energy and contributes to unnecessary greenhouse gas emissions.
Crime and Safety: Contrary to popular belief, excessive lighting does not always enhance safety and can create areas of glare that obscure vision.
Night Sky Heritage: Light pollution robs us of the ability to see the stars, diminishing a natural heritage that has inspired humanity for millennia.
What Can Be Done to Combat Light Pollution?
The good news is that light pollution is reversible. Unlike many other forms of pollution, we can take immediate steps to mitigate its effects. Here are some actionable solutions:
Use Shielded Lighting: Install fixtures that direct light downward rather than outward or upward.
Choose Warmer Colors: Opt for lights with warmer color temperatures to minimize blue light emissions.
Install Timers and Sensors: Use technology to ensure lights are only on when needed.
Advocate for Responsible Lighting: Support policies and initiatives that aim to reduce unnecessary lighting.
Raise Awareness: Educate others about the impacts of light pollution and encourage them to make changes in their lighting habits.
Check Dark Sky International to learn more about light pollution and what can be done.
