Light Pollution Kinds, Consequences, & Solutions

May 2014

There are 4 Kinds of Light Pollution

• Glare

• Over-illumination

• Light Trespass

• Skyglow

GlareA bright light in your field of view can make it impossible for your eye to adapt to see in your otherwise dark surroundings

Over-illuminationThe excessive use of light

Light TrespassUnwanted light originating from beyond your property.

SkyglowLight that made it up to the atmosphere to be scattered back

down to earth. A sky affected by skyglow never really gets dark.

Light Pollution has Consequences

• Wastes Energy

• Affects human and animal health

• Changes Ecosystems

Wastes EnergyLight that is not directed down toward the ground where it

can be used is completely wasted—no one uses it.

Harmful to Life• Artificial light at night was

introduced to life on Earth relatively recently. Life had adapted to bright days and dark nights.

• After hatching sea turtles use moonlight to find their way to the ocean. Additional lights hinder their ability to get to the ocean.

• Many insects are thought to use moonlight to navigate. Additional lights make it impossible for them to function at night.

Changes EcosystemsBats are known to avoid foraging in heavily light polluted areas. An ecosystem can change drastically when bats abruptly stop foraging and dispersing seeds.

Solutions to Light Pollution Problems are Surprisingly Simple

• Shield lights

• Only use light where and when needed

Shielded lightsA properly shielded light allows no light to go upwards where

it can’t be used, yet still amply lights the area around it.

Use light only where and when neededTurn off lights when they’re not in use. Don’t use more light

than you need in an area.

Enjoy the starsHelp stop the loss of the night sky by doing your part to fight

light pollution.