Clouding the issue

PUBLISHED : Thursday, 21 December, 1995, 12:00am
UPDATED : Thursday, 21 December, 1995, 12:00am

LEGISLATORS voted against the proposal based on the wrong premise. They wanted evidence that petrol is more 'environmentally friendly' than diesel. Neither are environmental-friendly because both emit harmful pollutants. Also, the exhaust emissions of the two types of vehicles are inherently different. Comparing their relative environmental-friendliness is misguided.

A more useful way to assess the public health benefits of the scheme is to start by examining Hong Kong's air quality objectives. These are the air quality standards which should be met.

The one standard which Hong Kong consistently fails to meet by a substantial margin is the level of respiratory suspended particulates (RSP). Its adverse effect on health includes serious respiratory and cardiovascular illnesses, with the elderly and children being most susceptible.

It is accepted that the biggest culprit for the emission of RSP in Hong Kong right now is the diesel fleet. It is for this reason that we need to address RSP quickly and efficiently.

The administration's proposed scheme targets diesel vehicles below four tonnes. This includes taxis, public light buses, school buses and light goods vehicles. There is enough available data to assess reasonably accurately how much RSP levels would be reduced.

Opponents argue that while RSP can be brought down, other pollutants such as carbon monoxide and dioxide, plus benzene levels would increase. This is true, but the expected increases are relatively small and, most importantly, the air quality objectives for them can still be met comfortably.

For some reason, many legislators prefer to ignore this and instead argue that they do not trust the Environmental Protection Department's (EPD) data. Having said that, it was frustrating that officials were not more aggressive in countering many groundless arguments. Perhaps technocrats are not trained for such combat, when they need to be in such an assertive political environment.

The other argument is that Hong Kong does not need the scheme to lower RSP; better maintenance and cleaner fuels can do the job just as well. The problem is that diesel vehicles, even brand new ones, emit much more RSP than petrol using models. Coupled with the estimated increase in the number of these vehicles on the road, better maintenance will help, but it is unlikely to ensure that Hong Kong can meet its RSP objective in the foreseeable future.

Cleaner fuel will also help, but we still need to reduce RSP to lower the health threat.

As for diesel vehicles over four tonnes, there are no petrol driven alternatives on the market. Thus, to reduce RSP levels, we must rely on better maintenance and engine standards, plus cleaner fuel.

Adopting the scheme does not mean we ignore developing technology, such as electric cars. Any new law could require a review of the available technology every five years. As well as reducing the number of diesel vehicles, the administration must do more to reduce the total number of vehicles on our roads. This will require improving and expanding public transport. For example, more subways and ferries, and giving priority to buses on the roads during rush hours. The Government must also act to further reduce other pollutant levels. Hong Kong consistently fails the nitrogen dioxide air objective.

Finally, whether the scheme is voluntary or mandatory, it will fail if the livelihood of diesel vehicle owners is not properly taken into account. Operators are concerned that the cost of maintaining a petrol vehicle is much higher than the EPD estimates. As such, they would have to raise fares to a level which would badly effect their business.

The administration's calculations are unconvincing. But what needs to be done is not to throw the scheme out, but for the trade and officials to get together to agree on the basis for various financial incentives for diesel owners to switch to petrol.

Let this process begin now. Harping on about the comparative environmental-friendliness of diesel and petrol is barking up the wrong tree.