Officially, Hong Kong will not get a long-awaited set of new air-quality targets until next year. But the government has already unveiled a plan to meet them by 2020. That it will take seven years to make a real difference to the city's unhealthy roadside pollution reflects inaction in the past. Critics have said the plan mainly rehashes old ideas. But at least it promises action according to a timetable for which Leung Chun-ying's administration can be held accountable. In his maiden policy address the chief executive declared the quality of the air we breathe to be a core livelihood issue. He got off on the right foot by promising to legislate next year to require all ocean-going vessels to use low-sulphur fuel when berthed in the city, and pledging HK$10 billion in cash incentives for operators to replace or remove the dirtiest commercial vehicles on our streets by 2019. The new plan says that if all the measures now planned are fully introduced, roadside pollution will begin to drop in the next two to three years, and improve significantly in four or five. It includes more clean-fuel measures for shipping; retrofitting 1,400 franchised buses with diesel emission controls; low- emission zones for buses; and strengthened emission controls for petrol and LPG vessels. Announcing the plan, Environment Secretary Wong Kam-sing was joined by top transport, development, and food and health bureau officials, in a gesture of co-operation and commitment across government. But Friends of the Earth was right to point out the lack of a mechanism for co-operation and each bureau's responsibility for meeting targets. Leung needs to ensure that bureaucratic turf wars do not frustrate his agenda. After all, officials admit that some targets will be hard to meet in any event, and that the level of nitrogen dioxide, the dominant pollutant, will still be almost double the new standards despite a 40 per cent drop. Environment undersecretary Christine Loh Kung-wai said the city's population and building density made it difficult to tackle nitrogen dioxide and that more pedestrian-only areas or traffic diversions might be necessary. Elsewhere, strategies such as electronic road pricing have proved effective in easing congestion and reducing emissions. The latter idea was shelved here because of lack of consensus. Sooner or later, cleaning up Hong Kong's air will call for Leung to show strong political will.