Types of Light Pollution
Glare
Glare from unshielded lighting is a public-health hazard—especially the older you become. Glare light scattering in the eye causes loss of contrast, sometimes blinds you temporarily and leads to unsafe driving conditions.
Light Trespass
Light trespass occurs when unwanted light enters one’s property, for example, by shining unwanted light into a bedroom window of a person trying to sleep.
Skyglow
Skyglow refers to the glow effect that can be seen in populated areas. Skyglow is the combination of all the reflected light and upward-directed by unshielded lighting escaping up into the sky (and for the most part, unused). Shielding lights significantly reduces all three of these types of light pollution.
Ecological Impacts
Nesting Birds
Biologists have found that light pollution causes birds to begin nesting up to 18 days earlier in forested environments. The consequence could be a mismatch in timing -- hungry chicks may hatch before their food is available, which is extremely dangerous.
Bird Collisions
Light pollution can also cause bird collisions. The bright lights at night on large buildings attract birds in the same way that bright porch lights attract moths, which can result in fatal collisions. A recent study in 2014 estimates that between 100 million and one billion birds are killed in the United States each year as a result of collisions with buildings.
Baby Sea Turtles
Baby sea turtles, much like birds, use night from the night sky to guide them to sea and artificial lighting can cause them to wander inland which can lead them to be eaten or run over.
Plants
Light pollution can also hurt plants. Artificial lighting can cause the delay of leaf falling for a tree because it causes the tree to still think it's summer. This is dangerous to the tree since when winter comes, the snow will catch onto the leaves and break the branches.
Human Health
Light pollution also damages human health. Humanity evolved on this planet with reliable cycles of light and dark. The addition of light into what has always been darkness disrupts our natural circadian rhythm, or the internal cycle synchronized with our biological clock with the day-night cycle. Our circadian rhythm is controlled by the hormone melatonin. Secretion of this hormone is suppressed when we are exposed to light at night, specifically blue and white light that mimics what we experience under the daytime sun. This disrupts our health, exemplified by the fact that exposure to artificial light at night has been linked with an increased risk for all types of cancer.
What You Can Do
Change to low power and efficient light bulbs.
Change to low power and efficient light bulbs.
Change to low power and efficient light bulbs.
Changing any incandescent light bulbs you have at home for LED light bulbs can reduce the amount of light pollution and reduce the energy used. However, when choosing LEDs, make sure to use ones that produce warm-colors, like red, orange, or yellow. Blue light can cause glares and affect your eyes.
Shield lights and point them down.
Change to low power and efficient light bulbs.
Change to low power and efficient light bulbs.
Using a cover to shield the light down also reduces light pollution. This concentrates the light and prevents it from spreading to unnecessary places.
Turn off lights when not needed.
Change to low power and efficient light bulbs.
Turn off lights when not needed.
Last but not least, turning off lights when you’re not using it also helps. It reduces the amount of light thats exposed and also reduces energy use.