Light pollution is the excessive light that is created by us. It poses a threat to the eyes, disturbs the ecosystem apart from interfering with astronomical observations. It is high time that we take corrective measures to control it as each year the problem of light pollution is getting worse. We will take a look at the causes of light pollution and know some light pollution facts, but before that let us know the different types of light pollution.
Types of Light Pollution
Light Trespass: Light trespass is caused due to undesirable illumination of an area which causes light to spill to places where it is not required. An example of light trespass can be the illumination caused inside an apartment due to streetlights.
Sky Glow: If you live in an area where the levels of light pollution are relatively high, then you must have noticed an orange 'smog' in the night. This 'smog' is called sky glow and it is caused both due to man-made and natural sources.
Glare: Glare can be defined as the increase in contrast in a given field of view. While driving at night, we have to shield our eyes with our hands as the glare makes it difficult for us to see things clearly. Glare causes discomfort to the eye and can lead to road accidents.
Causes and Effects of Light Pollution
Light pollution is caused by uncontrolled emissions and reflections. The design of most of the light emitting sources allows a significant fraction of light to go up in the sky. Excessive use of light emitting sources also causes significant loss of light energy and increases the production of greenhouse gases. Careless outdoor lighting is also responsible for light pollution. Estimates point out that about one-third of the energy used for outdoor lighting is sent to outer space where it doesn't serve any useful purpose and causes light pollution. The rate at which the urban areas are expanding is contributing to the increase in the levels of light pollution.
The range of new outdoor lighting products has also led to an increase in the light pollution levels. Three decades ago, the outdoor lighting products that were available to the public were limited to incandescent lights, mercury vapor lamps, etc. but today more powerful fixtures are available. These products are more powerful than needed and are poorly shielded causing light to spill in areas where it is not needed.
Continuous exposure to bright light can cause neurological disorders such as insomnia, migraine and depression. It has far reaching effects on nature and animals. It interferes with the biological cycle of nocturnal animals, altering their feeding, migration and reproduction activities. Light pollution confuses birds and animals as can be seen from the way sea turtles turn towards the road instead of the ocean after hatching their eggs on the beach. Light pollution causes waste of energy and puts a strain on the already depleting resources on earth. The streetlights in US alone generate around 2.3 million tons of carbon dioxide in a year.
Preventing Light Pollution
One of the first steps that we need to take to fight light pollution is to ensure that all outdoor lighting equipment are manufactured in such a way that light is only pointing to the areas where it is needed. This will require manufacturers to design the lighting products with proper shielding materials. The government agencies have to also ensure that they install streetlights in such a way that light is not shining horizontally into the eyes of people.
We all will need to do our bit to control light pollution. People are not yet fully aware about this form of pollution and there is a common misconception that light pollution hampers only astronomical observations and therefore, it is an issue for only those associated with astronomy. We all have a part to play in controlling light pollution and it is important that we start educating ourselves, our neighbors and those who are at the helm of the affairs about the severity of this issue before it is too late. We hope that this article would have helped you in getting an insight into the causes of light pollution and the threat that it poses to us.