The 10th Earth Hour, WWF's annual global campaign to switch off all non-essential lighting, will begin on Saturday, at 8.30pm.

It could not come a moment too soon.

Hong Kong, with its dazzling skyline and streets buzzing with brightly lit billboards, has the worst light pollution in the world, according to a three-year study titled "Night Sky Brightness Monitoring Network", released in 2013 by the University of Hong Kong.

The report found parts of the sky above Tsim Sha Tsui were 1,200 times brighter than normal. Even remote areas of the Sai Kung countryside were found to be excessively bright.

That excessive amounts of light can disrupt our biological clock and affect brain and hormone function has been well documented, so supporting the Earth Hour campaign makes particular sense to Hongkongers. What doesn't make sense, however, is the government's reluctance to introduce legislation to control external lighting, following in the footsteps of major cities such as London, New York, Sydney and Shanghai.

Instead of tackling the issue head on, the powers that be have tiptoed around it by setting up the toothless Task Force on External Lighting, which, after years of study, in 2015 opted for the soft approach of voluntary compliance instead of legislation.

It's time the government stopped pandering to the tourism and advertising industries, which say they rely on lighting for business, and take a long hard look at the bigger picture: the damage light pollution is having on Hong Kong's environment and on people's health.

"The lights are on but nobody's home" could not be a more fitting idiom.