Light Pollution
- On December 14, 2022, the district administration of Ladakh designated six hamlets within the Changthang Wildlife Sanctuary as a “dark-sky reserve” — an area whose sky is free of light pollution.
- The increasing use of artificial light has led to the phenomenon of skyglow, which is when the night sky appears to be brighter than it should be. This has significant ecological, health and cultural consequences.
- A new study titled ‘Citizen scientists report global rapid reductions in the visibility of stars from 2011 to 2022’ found that non-natural light had increased the brightness of the artificial glow of the night sky, or skyglow, by 9.2-10% every year between 2011 and 2022.
- The study found that skyglow had brightened around 6.5% over Europe, 10.4% over North America, and 7.7% over the rest of the world.
- The study recommends using light sources that cast light at an angle below the plane of the horizon, capping the emissions of these sources and calibrating their output according to the total brightness at the spot being lit.
The Light Pollution Situation in India:
- The study had only a few observations from Asia, South America, and Africa. There were no entries from China or Brazil.
- A 2016 study reported that 19.5% of India’s population experiences a level of skyglow that would at least keep the Milky Way galaxy out of sight and at most render “dark adaptation for human eyes” impossible.
- A 2017 study reported that between 2012 and 2016, India’s lit area increased by 1.07-1.09% and the average radiance of “stably lit areas” increased by 1.05-1.07%.
Consequences & Negative Effects of skyglow:
- The increasing use of artificial light has led to carbon emissions due to the production and use of LEDs not decreasing.
- Artificial light at night affects both people and wildlife in significant ways, including deterring sea turtles from nesting, keeping trees from sensing seasonal variations, preventing young burrow-nesting seabirds from taking flight, killing clownfish offspring, allowing insect predators to hunt for longer, and disrupting the circadian rhythm.
- Circadian disruption can lead to an increased risk of breast cancer among night-shift workers, and can hamper the production of melatonin, which affects sleep, moods, and cognition.
- The erasure of the night sky also acts as a form of ongoing cultural and ecological genocide, erasing Indigenous connections to the stars.
