Light pollution might be tolerated in Hong Kong if it is caused by technology that reduces the amount of electricity used and, as a result, improves air quality. But the term has been redefined by a new energy-efficient product that has created another environmental problem - too much artificial light.
Light-emitting diodes that use less power to produce brighter and more elaborate advertising billboards, giving advertisers a bigger bang for their buck, enhance the city of light for tourists and sightseers, but not the quality of life for many residents.
The latest LED display to upset nearby residents and green activists with its directional, concentrated light stands atop the new The One mall in Tsim Sha Tsui, close to others on iSquare and Star House. One advertising agent predicts that all illuminated signs in the city will be LEDs within a decade, compared with 1 per cent a year ago and 3 to 4 per cent now.
They are not the only culprits. Complaints about intrusive commercial lighting, that can turn patches of night into day and illuminate an apartment like a disco, rose from 87 in 2007 to 377 last year - or more than 400 per cent, and are still rising.
The government has responded by ordering a public consultation on external light pollution, followed by a study commissioned by the Environment Bureau, the findings of which it is still digesting. Given that LEDs can only make the problem rapidly worse, some practical ideas are needed to balance legitimate competing interests, so that a renowned symbol of the city's vibrancy - a spectacular nighttime skyline - is not dimmed, nor the rhythms of people's lives unduly disrupted.
That resonates with the mixed feelings of green activists who welcome LED lights for saving power, but are concerned about the potential for severe light pollution in a city already blighted by poor urban planning. If LEDs prompt some effective action on light pollution, that will enhance their environmental credentials.