In recent years, the brightness of Skyglow has increased significantly due to the prevalence of non-natural light. This phenomenon, which sees an all-encompassing sheet of light cast across the night sky in urban areas, is resulting in notable environmental, health and cultural implications. A recent study delves into the increase in Skyglow and the associated effects and potential solutions.
Understanding Skyglow
Skyglow refers to the brightening of the night sky over populated areas due to artificial lighting such as streetlights, security floodlights, and outdoor ornamental lights. This pervasive light affects nocturnal creatures by flooding into their eyes and misleading their path. Regarded as a primary component of light pollution, the impact of Skyglow goes beyond the ecological realm, causing considerable health and cultural repercussions.
Global and Indian Scenario of Skyglow
Around the globe, Skyglow has brightened by approximately 6.5% over Europe, 10.4% over North America, and 7.7% over the rest of the world. These findings contradict satellite-based data that suggested an increase rate of around 2% per year, a discrepancy likely due to satellites’ inability to sense LEDs’ blue light and to study light emitted parallel to the ground.
Specifically looking at India, studies show significant effects of Skyglow. In 2016, research showed 19.5% of India’s population, the lowest among G20 countries, experiences a level of Skyglow that obscures the Milky Way’s visibility and makes it impossible for human eyes to adapt to the dark. Between 2012 and 2016, India’s lit area expanded by 1.07-1.09%, and the average radiance of consistently lit areas increased by 1.05-1.07%.
The Implications of Skyglow
The impacts of Skyglow are multi-fold, spanning wasted energy and money, disrupted ecosystems and wildlife, and human health issues. Beyond causing unnecessary economic and environmental strain, the influence of Skyglow extends to plants and animals, disrupting their life-sustaining behaviors. Examples include deterring sea turtles from nesting on lit beaches and preventing clownfish eggs from hatching. It also impedes tree’s ability to sense seasonal variations.
From a human health perspective, exposure to artificial light at night can disrupt our circadian rhythm – the sleep-wake pattern governed by the day-night cycle. A 2009 review concluded that circadian disruption could increase night-shift workers’ risk of breast cancer by 40%. Additionally, Skyglow’s continual removal of clear night skies severs indigenous communities’ connection to the stars, equating to a form of ongoing cultural and ecological genocide.
Suggested Solutions to Mitigate Skyglow
Research suggests several remedial measures to counter Skyglow. Recommendations include directing light sources below the skyline, capping emission levels, and adjusting output according to total brightness at the spot being illuminated. When lights cannot be turned off, they should be shielded to prevent unnecessary light spill into the surrounding environment and sky.
The International Dark-Skies Association has certified over 130 ‘International Dark Sky Places’, where artificial lighting has been modulated to reduce Skyglow and prevent light trespass. However, almost all these areas are in developed Northern Hemisphere countries. Therefore, less-developed, species-rich regions currently experiencing less light pollution present an opportunity to invest in suitable lighting solutions before local fauna are severely affected.
Last Modified: February 19, 2024