Hong Kong people love to talk big about environmental concerns, but are doing little in environmental protection.

There is, of course, a lot to be said about air pollution, dirty streets, refuse in the harbor and beaches, dying trees and shrinking green spaces. All these are genuine complaints that Hong Kong people, especially the young elite, harp on all the time.

Undoubtedly, the greatest environmental concern among Hong Kong people is worsening air pollution on the streets caused by vehicle emissions. Government efforts to enforce wider use of vehicles running on clean engines have produced mixed results. Results of the latest survey by the Environmental Protection Department show a marked drop in roadside pollutants, resulting from a 90-percent decline in the number of so-called "smoky" vehicles since 1999.

But nitrogen dioxide (NO2), which poses a serious health hazard, actually increased by 3 percent during the same period. To further improve roadside air quality and tackle the NO2 problem, the government has introduced incentives to promote the use of clean diesel commercial vehicles in compliance with Euro IV standards.

Despite hikes in car registration fees, the number of private cars on Hong Kong's roads has reached more than half a million. Proposals to further raise the relevant taxes and adopt other measures, such as road tolls, to discourage car ownership have been vigorously resisted by motorists, many of whom have been the most vocal in speaking out against air pollution. To them, it is somebody else's business when it comes to environmental protection, while they flaunt their fancy sports cars and gas-guzzling SUVs.

The answer to the air-pollution problem, it seems, lies not so much in punitive measures against car ownership, but rather in promoting the use of clean cars through sufficiently attractive incentives. The government's program to speed up the adoption of clean diesel commercial vehicles may need to be revised in the light of the Volkswagen scandal, in which diesel engines were found to be fitted with devices that could detect when they were being tested for emissions. This deception, suspected to be a widespread practice across the car industry, shows the shortcomings of diesel technology and may be why NO2 in Hong Kong has been rising while the levels of other pollutants are falling.

It is still too early to conclude that diesel is a dead-end technology in motoring. But the disclosure of cheating at Volkswagen and allegations against some other automakers shows that the costs of making diesel engines which comply with the new emission standards set by the United States and Europe may be too high.

The alternative is going electric. Great strides have been made in the development of electric vehicles (EVs) in recent years. Nearly all the major automakers in the US, Europe and Japan are selling their own EV brands which guarantee zero emissions.

EVs are particularly suitable for Hong Kong due to their limited range - a major disadvantage in most places. But that is not much of an issue in this compact city where the distance of an average trip is never too long. Advanced battery technology has greatly lengthened the range of an average EV, which matches cars with conventional engines both in terms of performance and comfort.

The Hong Kong government has introduced a host of measures to promote the use of EVs, including scrapping the registration tax on them by March 2017 and allowing businesses to claim full tax cuts for the cost of EVs in the first year of purchase. The government has also built more than 1,200 EV chargers for the public.

But the rate of adoption has been lackluster. By the end of August this year, there were 2,650 electric cars on the roads, or about 0.5 percent of the city's total number of private cars.

Apparently, the government needs to do more to encourage the use of electric cars by widening its incentive scheme to include private car owners. Instead of just deferring payment of first registration fees by two years, it should consider cutting the fees further to offset the higher average prices of electric cars. This will be a fair reward for those who do care about the environment and opt for clean vehicles.

There is also a need to enforce road tolls in busy commercial districts to ease traffic congestion that exacerbates air pollution. It makes great sense to make polluters pay for their transgressions.

Car ownership in Hong Kong, which boasts one of the world's most efficient public transport systems, is a luxury most people can do without.

The author is a veteran current affairs commentator.

(HK Edition 10/12/2015 page9)