Have you ever seen our galaxy? Milky Way, right? Few might have seen. Many of you will say, 'Ohh, how could we see that?" Well, it is easily visible in rural areas or star gazing centres (becoming popular nowadays) because of clear night sky with the least interference of artificial light. Are we able to experience such clear nights these days? No. The reason is excessive Light Pollution. So what is this Artificial Light Pollution?
Highly illuminated and disoriented lights used by us for various purposes have created light pollution. According to an article published, in Mumbai city, residents in buildings near to street have started increasing the thickness of window curtains to resist the intense light emitted by billboards, vehicles, and many other sources. Yes, it's creating havoc all over the world and increasing day by day. In cities nowadays we don't feel like its clear night.
Major Components of light pollution include:
Glare: Excessive and uncontrolled light causes glare, which is a visual experience. It might be debilitating or merely inconvenient.
Skyglow: Dust and gas molecules in the atmosphere scatter light that is either emitted straight upward by luminaires or reflected from the ground, creating a bright backdrop. It has the effect of making it more difficult to see the stars.
Light trespass: Unwanted light invading a person's property or an area of concern is known as light trespass.
Clutter: Excessive groups of lights are referred to as light clutter. Light clusters can cause confusion, divert attention away from possible hazards, and even result in accidents. Clutter is especially visible on highways with poorly placed street lights or brightly illuminated advertisements around the lanes.
The above picture shows skyglow above a Pune city (photo was shot during a trek to Torna fort, it stands at an altitude of 1403 m above mean sea level and 70 km far from Pune city). Light oriented upwards in the sky from the ground collide with the particles in air and this glow occurs. Highly illuminated billboards, disoriented led lamps, advertising signs, skyscrapers, highly illuminated sporting venues are few major sources of light pollution.
This blog published in Times of India describes about ill-effects of light pollution.
Effects on birds and animals:
Excessive light pollution is causing harm to humans as well as nocturnal birds and animals, infact its affecting the whole environment. Numerous moths, butterflies, fireflies are rarely sighted in cities. Sleep cycles of all natural beings are disturbed. Reports suggest that every year light pollution is increasing by 2.2%. Can you imagine how intense it could be after 10 – 20 years if it increases at this rate? You may know few birds and animals travel and wander during night time. Nocturnal birds use the pattern of stars for their navigation during dark nights (Franz and Eleanore Saver, 1960). This excessive glow of artificial light is highly confusing to them. They are losing the sense of actual night. Numerous researches are done on this topic and proved the ill effects of light pollution. According to Herbert(1970) “when a bird flies into lights at night it loses its visual cues to the horizon and bird uses the lights as a visual reference, resulting in spatial disorientation.” This causes alteration of a straight flight path and results in halting of birds near the light longer than if the flight path was straight. Many contexts report that death or injury from collisions is very obvious. These delays and altered migration routes result in a non-uniform cycle of their arrival at breeding ground.
What we can do?
We can opt for few simple things that can be done to reduce light pollution, like;
· The easiest step is to switch off unwanted lights in homes and backyard during night times.
· Use lights of standard luminance.
· Cover the outdoor lights such that they don’t luminate upside sky.
· Try to use warm lights wherever possible.
· Awareness is very important, you can make your friends and family aware of this rarely explored phenomena and solutions to it.
These are few things a common man like us can start with. Why wait for a change to happen, if you can start it with yourself.
Written by:
Omkar Nagawade,
Research Scholar at IARI.
Worth saying, need more awareness