Light pollution is growing with the growing population. As a result the sky looks different at night, and less light comes from the stars. Country sky looks a lot different than city sky does. Light pollution is affecting the whole world. Light pollution is caused by artificial light that is used in excess. Light trespass, over-illumination, glare, light clutter, and skyglow are all examples of light pollution. Light pollution affects habitats, people, and animals. It is also a cause and effect of global warming. In the United States, billions of dollars are wasted annually on light pollution. Light pollution has become a major problem in the United States over the years.

Light trespass occurs when unwanted light enters one’s property (Light Pollution). Light trespass causes problems like sleep deprivation. Some cities in the United States have developed standards for outdoor lighting. The Dark-Sky Association was started to reduce light that was going up into the sky that was reducing the visibility of stars. Two million barrels of oil are wasted per day in energy because of over-illumination, or excessive use of light. There are several factors that cause over-illumination: improper design of high levels of light, incorrect choice of light bulbs or fixtures, and inadequate lighting maintenance. Most of those causes can be corrected quickly and inexpensively. Glare can be put into three different categories: blinding, disability, and discomfort glare. Blinding glare has effects like staring into the sun, blinding, temporary or permanent vision deficiencies. Disability glare has effects like being blinding by car lights, causing sight capabilities to be reduced. Discomfort glare does not cause a dangerous situation, but it is annoying. Glare can cause fatigue if it is experienced over long periods of time. Excessive groups of lights are categorized as light clutter. They may cause confusion, cause accidents, and distract people from obstacles. Clutter is mostly noticed on roads that have badly designed street lights or brightly lit advertising. Clutter presents hazards in aviation safety also. Safety lighting must compete with the light clutter so pilots know where the runway is. Skyglow refers to “the ‘glow’ effect that can be seen over populated areas” (Light Pollution). The glow is the combination of all light reflected from the earth into the sky. It is scattered in the atmosphere. Skyglow can be reduced by using lighting fixtures that limit the amount of light emitted.

Light pollution disrupts ecosystems. Light pollution is harmful to nocturnal wildlife. Some species will stop reproducing because of habitat destruction caused by light pollution. Light pollution is threatening Florida Sea Turtles (Light Pollution Information). Lights can confuse birds when they are migrating at night. Light is used by many animals to understand and become familiar with the environment they are being born and raised in. Because of artificial light, mating and reproduction is becoming harder for some animals. In the case of fireflies, they use lights to attract mates, but artificial light is making them harder to see. Light pollution can increase or decrease competition between species just by changing the lighting.

Light pollution is a “symptom” of global warming. Lighting uses electricity; electricity is generated by burning fossil fuels, which increases carbon dioxide in the atmosphere, which adds to global warming and climate change (Green Living Tips). Changing lighting and light pollution can decrease the effect on global warming. By changing to LED lights, the usage of electricity decreases so coal does not need to be burned as much. Changing traffic lights in Los Angeles decreased the wattage the city used. The city now uses only ten Watts per light instead of the one hundred fifty Watts they previously used (Waltarrrr).

Light pollution has become a major problem in the United States. Excess light has disrupted our vision of the night sky. People living in the city do not see how the sky looks anymore. Light and air pollution “cover” the beauty the sky has at night. Excess artificial light causes light pollution. Light trespass, over-illumination, glare, light clutter, and skyglow are all examples of light pollution that are easily fixable. Light pollution affects habitats, animals, and people all over the world.