The Standard – Monday, August 18, 2008 – Grace Tsoi
Hong Kong has become 1,000 times brighter than countries such as the United States, a problem which stargazers say may rob the full moon of some of its magic during the Mid-Autumn Festival.
According to research by the Hong Kong Astronomical Society, light pollution in the territory is so serious that only the brightest objects such as Venus can be seen. But not only light pollution is lowering Hong Kongers’ chances of enjoying a bright full moon – there is also the matter of air pollution.
Instead of a clear dazzling full moon, what may be seen is a “yellow” moon, according to astronomy consultant Ricky Tsui Lik-to. It is not a “normal moon,” he said, adding the moon’s natural color as seen from Earth is white, but pollutants in the air act like a filter, giving it a yellow tinge.
His advise for people wanting to watch a dazzling white moon is to switch off unnecessary lights. Stargazers also said switching off the lights can lower emissions of greenhouse gases, which are the culprits behind global warming.
The Tai Po Environmental Association and Kadoorie Farm and Botanical Garden have started a “Lights-off Moon-on” drive in which people are encouraged to switch off decorative lights. The association said people can contribute toward reducing emissions by switching to fluorescent lights. It said a household using five compact fluorescent lamps can reduce emissions by 0.1 tonnes a year. The commercial sector, according to the association, can also do more by switching off lights, especially on billboards when they are not in use.
The group said a 3,000-watt bulb switched off for three hours each day over a year can reduce carbon dioxide emission by one tonne.