Hong Kong has seen some of the city's worst ever air pollution over the past few days. Readings for various pollutants have been extremely high, and some parts of the Pearl River Delta on Monday recorded the highest pollution levels (Grade V) even by mainland standards. These were well above the air quality guidelines set by the World Health Organisation.
The government blamed light winds for the poor air quality. In other words, if there had been more wind, the pollution would have been blown away, rather than enveloping us.
The truth is that the region's air quality has become extremely poor. Day in, day out, emissions are so high that, without stronger winds to dissipate the pollution, we suffer acute conditions. Indeed, most of the time, we are already breathing chronically bad air. The problem is not the wind, it's the pollution.
The reality of extremely bad air pollution becomes undeniable when the winds are light; the bad stuff just hangs around in the air. So, just to repeat: the reason for our extremely bad air is not the light winds, it's the high pollution levels.
In 1998, the government acknowledged that air pollution was a major and pressing problem. It said that 'we should be satisfied with nothing less than a world-class environment'. The administration concluded that it needed to focus on two key areas: first, reducing roadside air pollution - something that is within Hong Kong's control; and, second, working with Guangdong to reduce regional air pollution.
Over the next few years, the government had taxis switch from using diesel to liquid petroleum gas, and minibuses have also started to use LPG. It has offered a concessionary duty rate on ultra-low-sulfur diesel, for diesel vehicles - mostly buses and trucks. Owners have been encouraged, through subsidy schemes, to add particulate traps; and any new vehicles purchased have to meet the latest Euro environmental standards. The latest scheme involves providing subsidies to replace old trucks.