Tackling air pollution overhanging an area must be based on detailed knowledge of the sources and formation of the air pollutants. Only an air quality modelling system (i.e. a set of inter-linked mathematical equations solved on a high-speed computer) is up to the task of putting together all the information relevant to air pollution in a coherent framework.
Since 1993, Christopher Fung has been working for the Environmental Protection Department, guiding the development of numerical air quality modelling systems and their applications in support of environmental impact assessment and air quality policy formulation, resulting in realistic emission reduction targets.
Over the last two decades, our awareness of Hong Kong’s air pollution problems has grown, from that of a local issue concerning one or two non-interacting pollutants to that of a regional or a continent-wide issue involving complex transport patterns and many chemically reacting pollutants. Growing together with this awareness are the tools needed to dissect and understand the air pollution pattern.
The Hong Kong Government has introduced and developed a number of tools to simulate the air pollution phenomenon on various scales with a view to seeking effective solutions to problems. A simulation system called Pollutants in the Atmosphere and their Transport over Hongkong (PATH) was developed and used in various studies, notably the Pearl River Delta Air Quality study completed in 2002 which set the emission reduction targets to be achieved by 2010. The further study involves determining what measures or combinations of measures are required to bring our air quality in line with more stringent air quality standards.
Given that new air quality simulation tools are being developed, the Hong Kong Government is also upgrading its own set of tools so that some important pollutants like particulates can be simulated more accurately. It has also planned to bring all assessments – be it local like building a small road, setting up a process that will emit some pollutant or works on a large scale like building cross-border road networks – under one consistent simulation framework. This would ensure that all projects with air quality implications would be assessed under the same comprehensive framework, making overall planning for better air quality possible.
There are plans to work together with our Chinese counterpart to further develop models and databases and to compare model results with a view to gaining a more nuanced understanding of the causes of air pollution in the region. This will lay the foundation for and prompt further action within the region.
When it comes to making a change for the better, we need moral courage. In many cases, this moral decision has to be informed by knowledge – detailed technical information. When courage and intellect join hands, a solution is possible for many of the inter-related problems (e.g. environmental degradation and poverty) that we face.