What is Light Pollution?

Light pollution is the excessive, misdirected, or obtrusive artificial light that brightens the night sky and disrupts the natural darkness.

Types of Light Pollution

1. Sky Glow

The brightening of the night sky over inhabited areas, caused by artificial lights scattering in the atmosphere.

2. Glare

Excessive brightness that causes visual discomfort and can reduce visibility.

3. Light Trespass

When unwanted light enters properties, such as streetlights shining into bedroom windows.

4. Clutter

Excessive grouping of bright, confusing light sources, commonly found in urban areas.

Why Does It Matter?

Impact on Wildlife

• Birds migrate at wrong times due to artificial lights
• Sea turtles cannot find their way to the ocean
• Insects are attracted to lights, disrupting ecosystems
• Nocturnal animals have their hunting patterns disrupted

Impact on Human Health

• Disruption of circadian rhythms
• Sleep disorders
• Increased risk of obesity, depression, and certain cancers
• Eye strain and fatigue

Energy Waste

• 30% of outdoor lighting in the US is wasted
• Costs $3.3 billion annually
• Generates 21 million tons of CO2 per year

What Can We Do?

1. Use shielded lighting that directs light downward
2. Install motion sensors to reduce unnecessary lighting
3. Choose warm-colored LEDs (2700K or lower)
4. Turn off lights when not needed
5. Support dark sky initiatives in your community
6. Measure and report light pollution using SkyQI

Conclusion

Light pollution is a growing environmental problem, but unlike many environmental issues, it can be reversed quickly with proper lighting practices and community awareness.

Take action today: Upload your first sky reading to SkyQI and help us map light pollution in your area!