Reduce Light Pollution: Top 9 Strategies

What is Light Pollution?

We’ve all heard about different kinds of pollution-air pollution from carbon monoxide, water pollution from industrial waste, and soil pollution from pesticides. But one often overlooked type relates to artificial light, called light pollution.

Light pollution is unnecessary, misdirected, or improper artificial outdoor lighting that:

• Generates light spillover into unwanted areas like nearby properties
• Produces unnecessary glare that makes it difficult to see at night
• Creates the inability to see the night sky properly and generates skyglow in populated areas
• Wastes energy and increases operating costs

What Can We Do to Reduce Light Pollution?

Fortunately, there are many practical strategies to reduce light pollution. Here are nine effective approaches:

1. Use LED Lights

LED light technology has advanced significantly in recent years. They are typically the best type of light to help reduce light pollution because they have more focused light beams than other types of lighting, such as fluorescent or metal halide.

This helps prevent spillover into unwanted areas. Other typical benefits of LEDs over traditional lighting types include:

• Longer operational lifespan
• Lower energy consumption
• Better light quality and control
• Superior dimming capabilities

2. Use Shades or Covers That Direct Light Downward

Shades or covers help light focus on the intended lighting area, producing less spillover. They can be part of the original light fixture or purchased separately. LED lighting is typically very directional, making it easier to aim light where needed compared to traditional light sources like metal halide or high-pressure sodium lighting.

3. Minimize Your Light Use in General

One straightforward way to reduce light pollution is to use less lighting overall:

• Use fewer lights: Only install what is necessary for safety and function
• Create smaller targeted areas: Focus illumination precisely where needed
• Reduce duration: Outdoor lights don’t need to operate all night except for security requirements

4. Reduce Decorative Lighting Usage

Decorative lighting adds ambiance to outdoor spaces, especially during holidays or celebrations. However, it’s easy to overuse. Show restraint with decorative lighting, and avoid leaving it on continuously day and night.

5. Use Lighting Controls

Modern lighting controls can automatically limit light usage. Common options include:

• Dimmers: Reduce light intensity based on needs
• Motion sensors: Activate lights only when someone is present
• Timers: Control when lights turn on and off automatically

6. Direct Light Away from Neighbors Using Shields

Light shields are accessories that attach to light fixtures to focus light downward or inward, preventing spread in unwanted directions. They are also known as light shrouds or glare shields, providing benefits including glare reduction and improved night vision.

Standard Wall Pack Light Shields

LED semi-cutoff wall packs or LED full-cutoff wall packs already feature designs that focus light downward, typically requiring no additional shielding. However, if you have a standard wall pack, you can further reduce light pollution by adding a shield attached to the top of the fixture.

Shoebox / Parking Lot Light Shields

For LED shoebox lights or LED parking lot lights, back shields can be installed to stop the light from spreading backward. This prevents light trespass onto neighboring properties and keeps light focused on the parking lot or intended illumination area.

Stadium / Sports Field Light Shields

For LED stadium lights, shields can reduce both upward light pollution and sideways glare for players and spectators. This helps prevent lights from affecting players’ ability to track balls hit or kicked in the air. Most sports field lighting uses tight optics, so properly designed glare shields typically won’t affect the illumination of the playing field.

Flood Light Shields

LED flood light shields can be installed on the top and/or sides of fixtures to prevent light from going upward or sideways. This ensures only the intended target area receives illumination while limiting upward light trespass.

Should You Use Light Shields with LED Lights?

LED lights are typically more directional than other lighting types, such as fluorescent or metal halide. Street lights, LED parking lot lights, and flood/spot fixtures each have defined beam angles. However, they may still benefit from shields in some applications, particularly in densely populated areas.

Illustrated Guide to Properly Shielded Light Fixtures

The graphic below shows examples of shielded and unshielded light fixtures. When a light source is not properly shielded, two issues commonly occur:

• Light spreads in multiple directions, causing spillover into unwanted areas
• Light is not properly focused downward, creating glare issues

7. Avoid Using Lights in the Blue Spectrum

Light color is measured in Kelvins (K), with values expressed as correlated color temperature (CCT). “Warm” colors appear red or yellow with lower CCT values, while “cool” colors appear white or blue with higher CCT values, typically starting around 6000K.

The most effective colors for reducing light pollution outdoors are yellow, red, and amber, which typically produce less glare and have minimal impact on nighttime vision. For outdoor lighting, use warmer color temperatures with CCT values of 5000K or lower. Avoid the blue light spectrum associated with LEDs having CCT above 5000K, as blue light typically has greater geographic reach and creates more glare.

8. Use Blinds or Curtains to Control Indoor Light

LED indoor lighting can also contribute to area light pollution when windows are uncovered, allowing light to spread outside buildings. This can be addressed by using blackout curtains or blinds to contain indoor lighting.

9. For Coastal Areas, Use Wildlife-Friendly Lighting

Some coastal communities require amber lights in outdoor areas for wildlife protection. For example, certain Florida areas mandate these lights to protect sea turtles. When baby turtles hatch near the ocean, they instinctively move toward water to begin life at sea. Artificial light from coastal structures can disorient them, causing them to head in the wrong directions and face danger from predators or vehicle traffic.

Note: Always check local wildlife protection ordinances and building codes, as requirements vary by location. Consider consulting with local environmental agencies for specific wildlife-friendly lighting requirements in your area.

The International Dark-Sky Association (IDA)

The IDA is a non-profit organization that promotes Dark Sky Compliance initiatives, providing resources to help reduce light pollution through:

• Educational programs and resources
• Lighting design guidance
• A Dark Sky Friendly list of IDA-approved products

Learn more at: https://www.darksky.org

For additional information about Dark Sky Compliance, see our detailed blog post: Dark Sky Compliance Guide

Professional Installation Note: Lighting modifications may involve electrical work. Always follow manufacturer guidelines and consult qualified professionals for installation to ensure safety and code compliance.