What is light Pollution?

"Light Pollution" is a form of environmental degradation in which excessive artificial outdoor lighting, such as street lamps, neon signs, and illuminated signboards, affect the natural environment and the ecosystem. The wasteful light emitted directly upwards or reflected upwards from poorly-designed artificial light sources can be scattered by clouds, fog, and pollutants like suspended particulates in the atmosphere. The night sky is thus brightened, leading to a reduced number of stars visible in the sky due to a decrease of the light contrast. From the composite picture of the Earth at night taken by satellite imagers, we can see that artificial lighting from human activities all around the world is illuminating our night sky wastefully. Most of them are caused by excessive and improper use of artificial outdoor lighting including:
  • poor/no shielding
  • directing light upward
  • unnecessary light during late night,etc.

Losing the Dark

To help raise public awareness of some of the issues pertaining to light pollution, the International Dark-Sky Association in collaboration with Loch Ness Productions created “Losing the Dark”, a 6.5-minute documentary, introducing the abuse usage of urban lighting and its influences on social, health, ecology and astronomy. The video also suggests some simple actions people can take to help mitigate the light pollution problem.

Multilingual flatscreen version

Multilingual fulldome version

Cantonese narration version