Sustainable growth in Hong Kong and the adjoining Pearl River Delta region will not be possible unless we collaborate more to clean up our air. Frequent occurrence of smog in the PRD region in recent years has caused deepening concern among the general public as well as the business community and our respective governments.

You are no doubt aware of the collaboration between the Hong Kong SAR and Guangdong Provincial Governments to slash emissions of four major air pollutants - namely, sulphur dioxide, nitrogen oxides, respirable suspended particulates and volatile organic compounds - in the region by 20% to 55% by 2010.

These are ambitious emission-reduction targets that require commitment in both resources and collaborative efforts in spearheading joint programmes to tackle the regional air-pollution problem.

Over the past few years, Hong Kong has launched extensive initiatives to reduce emissions from power plants, vehicular sources, and to tighten up the emission of volatile organic compounds. As a result, the local emissions of these four major pollutants decreased by 32% to 53% between 1990 and 2006.

In parallel, the Guangdong authorities have taken enhanced measures to improve energy-supply structure, retrofit power plants, tighten emissions from motor vehicles and phase out small power generating units.

As you can see, both governments are making the best endeavours to deliver the emission-reduction targets. But government efforts alone will not be enough. We need the support of different sectors of the community.

Firstly, the industrial sector. We recognise that many factories in the PRD cities while bringing economic prosperity, also contribute to the air pollution problem in the region. Most of them are in fact owned by Hong Kong companies. Working with the industries and the Guangdong authorities, we completed a Cleaner Production Technical Support Pilot Project in 2007.

The project has successfully demonstrated that cleaner production could be practicable and, in many cases, would also bring about economic benefits. To ride on the success, we commenced a five-year Cleaner Production Partnership Programme in early 2008 to engage more Hong Kong-owned factories in the PRD region in adopting cleaner production technologies.

By devoting $93 million and engaging the Hong Kong Productivity Council as the technological partner, we aim to help 1,500 factories to reduce pollution emissions and enhance energy efficiency, thereby joining the efforts of both the Hong Kong and Guangdong governments in improving the regional air quality.

Secondly, the energy sector. Power generation is another major air-pollutant emission source in the PRD region. Since 1997, we have banned the construction of new coal-fired power stations in Hong Kong in favour of cleaner gas-fired units. We have capped the amount of pollutants that power plants are allowed to emit. We are also tightening this in the years ahead. And, we have linked the two power companies' rates of return to their environmental performance.

We are also working hand in hand with the public to promote energy conservation. This will help alleviate air pollution and reduce greenhouse gas emissions.

We are working on legislation to implement a mandatory Energy Efficiency Labelling Scheme covering air-conditioners, refrigerators and compact fluorescent lamps in the first phase.

In parallel, we are preparing to mandate buildings to follow a set of energy-efficiency guidelines with a view to bringing down electricity consumption in buildings.

On the regional co-operation front, the Hong Kong SAR and Guangdong Provincial Government jointly introduced an emissions trading pilot scheme in January, 2007. The scheme provides a platform for thermal power plants in the PRD region to work together by way of trading excess emission quota to achieve the emission-reduction requirements in a more cost-effective manner.

Thirdly, the transport sector. Our strategy is to build up an efficient public transport system and reduce vehicle emissions. In a city of almost 7 million people, Hong Kong's clean and efficient public transport system carries more than 90% of the 12 million passenger trips daily.

We have the lowest car ownership rate of only 80 vehicles for every 1,000 citizens, when compared with 180 in Singapore, 550 in UK and 840 in the US. But still, we are pressing ahead with upgrading and expanding our railway network to further reduce reliance on motor vehicles.

We have announced plans to push ahead with 10 large scale infrastructure projects within the next five years, which include cross-boundary rail and road links. Implementation of these projects will not only expand the room for Hong Kong's further development, but will also link up our socio-cultural and business activities with more efficient transportation systems.

In addition, with closer and more efficient rail and transport links between Hong Kong and the neighbouring regions on the Mainland, we are looking forward to opportunities to foster greener modes of transportation in the PRD Region.

Looking into the future, we are conducting a major review of Hong Kong's Air Quality Objectives - or AQOs - with reference to the latest guidelines published by the World Health Organisation.

The review will recommend a comprehensive long-term action plan for achieving the new AQOs for Hong Kong. On the basis of the review findings, there might be scope for exploring a set of regional AQOs with our neighbours in the region.

Apart from the cooperation with Guangdong on air pollution, Hong Kong joins hands with other provinces along the Pearl River to promote environmental protection under the Pan-Pearl River Delta Regional Environmental Protection Co-operation.

In the past few years, we have shared our experiences on cleaner production, environmental monitoring, wetland protection and public participation in environmental impact assessment process.

This year, Hong Kong and Macau will jointly organise a technical workshop on the policy formulation, management and control of solid waste disposal and sewage treatment for the Pan-Pearl River Delta representatives.

Guangdong and Hong Kong have created an economic role model that has helped shape China's course of economic development. There is no reason why we cannot repeat such success in sharing the same vision to become the cleanest, greenest region in China. And we hope to pave the way with our actions for other regions and cities across China to follow in our quest for a more sustainable form of development for our country.

To take forward our collaborative efforts with Guangdong to a broader perspective, we propose to map out in conjunction with the Guangdong authorities a strategy that could strive to make Hong Kong and PRD one of the greenest regions in China.

Building on our success in the 2010 bilateral agreement, we see prospect for taking our collaborations to the next stage. Key areas for collaboration may include: formulating common air quality objectives; enhancing regional air monitoring network; joint development of renewable energy; deepening collaboration in respect of cleaner production, greening and afforestation, emissions trading and research and development. All these could bring fruitful discussions and eventually tangible results.

We envisage that actions taken to improve regional air would provide complementary reduction in greenhouse gas emissions.

We have maintained good dialogue through the Guangdong-Hong Kong liaison mechanism and we will continue to explore ways and means of how best we can climb new height in our cross-boundary collaborations.

Let me now turn to international co-operation. Global warming is one of the most important challenges facing our planet. We have seen a rapid build-up of momentum and determination worldwide in recent years to deal with this crucial issue. Hong Kong is facing up to the challenge.

International figures show that Hong Kong's greenhouse gas emissions, accounting for less than 0.2% of total global emissions, are among the lowest in the world in per capita terms. In 2005, that translated to about 6.5 tonnes per capita, compared to 24 tonnes for the US, 11 tonnes for the UK and Japan, and 9 tonnes for Singapore.

Between 1990 and 2005, our emissions intensity - the amount of greenhouse gases produced relative to the size of economy - actually fell by 41% in spite of the growth of our population and GDP.

This is a clear indication of a more efficient economy, and a more efficient use of energy. That said, as a responsible member of the international community, there is no excuse for us to hide in this comfort zone. We have been supporting international efforts to tackle climate change. We have pledged to meet the recent APEC agreement to cut our energy intensity by 25% between 2005 and 2030.

We also joined the C40 Large Cities Climate Leadership Group in October, 2007. London, Tokyo, New York, Beijing, Shanghai and Sydney are among the participating cities. We look forward to having useful exchanges and collaboration with these and other cities of the Group to collectively tackle climate change issues.

On the control of trans-boundary movement of persistent organic pollutants, we have taken specific actions under the Stockholm Convention to control the import, export, manufacture and use of these hazardous pollutants that are harmful to human health. The Convention was officially implemented in Hong Kong and the Mainland in July, 2007, when China's National Implementation Plan for the Stockholm Convention, including the HKSAR Implementation Plan, was launched.

With the purpose of also regulating the import and export of non-pesticide hazardous chemicals under the Rotterdam Convention, we are making a request to the Central People's Government for extending the Convention to Hong Kong after we enacted a new Hazardous Chemicals Control Ordinance on April 1 this year.

Hong Kong prides itself on being a world city, and being at the unique location in the PRD region as a gateway to the Mainland. Hong Kong and the adjoining PRD region contribute to and flourish on the growing Mainland economy. Hong Kong, Macau, Guangdong and the Pan PRD are brothers and sisters of a youthful, vibrant and fast growing regional economic family. We treasure our common success and we strive to make it a better home for our children.

Today, on top of the deep and long-standing economic ties, we have to build greater environmental interactivity in the PRD region that will support a long-term conversion to a sustainable green economy. All of us here, I believe, will continue to work toward this goal with strong determination and our utmost commitment.

Secretary for the Environment Edward Yau gave this address at the 2008 Macau International Environmental Co-operation Forum & Exhibition on "Regional & International Co-operation in Tackling Environmental Issues".