Seeing fewer stars? LEDs might be increasing light pollution

Subject: Environment

Section : Pollution

Context:

The sky has been brightening by nearly 10 per cent annually in the last decade, dramatically reducing star visibility across the globe.

Details:

Consequently, 30 per cent of the global stargazers have been robbed of a good view of stellar bodies.
At this rate of change, a child born in a location where 250 stars were once visible would be able to see only around 100 by the time they turned 18.

What is light pollution?

Light pollution, also known as photo pollution, is the presence of anthropogenic light in the night environment.
It is exacerbated by excessive, misdirected or obtrusive uses of light, but even carefully used light fundamentally alters natural conditions.
As a major side-effect of urbanization, it is blamed for compromising health, disrupting ecosystems and spoiling aesthetic environments.

Causes of increased light pollution:

Increased light pollution is due to the growing population, expanding settlements and the use of new lighting technologies such as light-emitting diodes (LED).
- Global LED market share rose to 47 per cent in 2019 from under 1 per cent in 2011.
The transition from traditional light to LED has led to the use of more light for longer durations.
The sky brightness increased by 9.6 per cent yearly. This is much higher than satellite-based estimates, which show that the sky brightness has increased by 2 per cent a year between 2012-2016.

What are the consequences of Light pollution?

Light pollution has ecological consequences, with natural light cycles disrupted by artificial light introduced into the nighttime environment.
Increased sky glow can affect human sleep.
In addition to threatening 30 per cent of vertebrates that are nocturnal and over 60 per cent of invertebrates that are nocturnal, artificial light also affects plants and microorganisms.
It threatens biodiversity through changed night habits, such as reproduction or migration patterns, of many different species: insects, amphibians, fish, birds, bats and other animals.

Recommendation:

Using lights only when, where and in the amount needed and avoiding lights that have ultraviolet or very cold white (shades of blue) could help.