Light Pollution

“Light Pollution” is a form of environmental pollution in which excessive artificial outdoor lightings affect the natural environment. Light pollution in Hong Kong is very serious. The main reason behind that are the artificial outdoor lightings. As there are many buildings scattered in Hong Kong, artificial lighting is omnipresent. The severe light pollution reduces the number of stars that are visible in the sky. The HKSAR Electrical and Mechanical Services Department, 20% of the total electrical consumption in Hong Kong was spent on lighting. Since electrical production is widely regarded as one of the major source of air pollutants, any misuse of electric lighting not serving its originally intended purposes means a huge waste of energy, and indirectly, generating air pollution. It is not uncommon to find poorly designed outdoor security light not using a lamp shade so that only a small fraction of light generated is directed to the ground, with a majority of light directed upwards towards the sky. Not only does this light provide no useful illumination, it also becomes a source of pollution to our night sky. IDA estimated that about US$2 billion, or equivalent to six million tons of coal, was spent in the US each year on wasteful lightings. Therefore light pollution not only means wasting energy and money, but also enhancing air pollution and global warming.

Outdoor lighting is an indispensable element of modern civilized societies for safety, recreation, and decorating purposes. However, if the lightening system is poorly designed and reached a excessive level, it will lead to a huge waste of energy and money. It as well robs us of our beautiful night sky.

Light pollution is quickly becoming a severe environmental problem worldwide.

The reduction in the number of star visible severely affects stargazing activities. With the subject of Astronomy soon to be included as part of the New Secondary School curriculum of Physics, we need our night sky now