Hong Kong's nighttime skyline is iconic, a megawatt cacophony of billboards, neon signs and video walls. Visitors find views of Victoria Harbour from The Peak breathtaking, but the dazzle and blitz of light from bustling streets after dark are what they most remember of our city. There is another side to the story, though, one lived by residents of crowded urban areas and people yearning to connect with nature. To them, the brilliance can be a nightmare, a fact borne out by a study showing that there is perhaps no worse place on earth for light pollution.
University of Hong Kong researchers were shocked by findings that showed brightness levels so excessive that health and wildlife could be harmed. Above the premier shopping district of Tsim Sha Tsui, brightness levels were 1,200 times more than the night sky, while they were 130 times higher at the Wetland Park in Tin Shui Wai. Nowhere in the world has there been so extensive a study of light pollution and it is good that the work has been carried out in our city. The findings are reason for public debate on whether it is time to replace voluntary technical guidelines with tougher measures.
Earth Hour tonight will give a taste of what less lighting means. Participants in the annual international event organised by the WWF will turn out non-essential lights for an hour from 8.30pm to highlight climate change and the need to use less fossil-fuel-produced electricity. A good response is unlikely to dim the golden glow above Hong Kong enough to see the stars, but will certainly put a dent in power usage. It will also send a message to retailers, advertising companies and building owners and managers of the need to better handle lighting.
Stargazers see that need. Beyond a scientific interest, there are those with a desire to be reminded of our place in the universe. Research shows excessive light also harms wildlife. But it is the effect on human health that is most worrying. Light pollution can get in the way of a good night's sleep and that could lead to depression, heart disease and cancer.
Hong Kong has no restrictions on excessive use of light, only voluntary guidelines. A government task force on light pollution has made limited headway after 20 months of work, due, according to one member, to resistance by vested interests in the advertising, property and tourism sectors. Laws have to be a last resort. With complaints and concern rising, authorities have to do more to educate and encourage self-regulation.