THE ENVIRONMENT
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Energy Efficiency and Conservation
The growth of Hong Kong's economy has led to a substantial demand for energy. A major proportion of the territory's energy comes from fossil fuels and is non-renewable. The government recognises the need to use energy efficiently to conserve energy resources, reduce pollution and prevent global warming. An energy efficiency office was set up in the Electrical and Mechanical Services Department in August 1994. Current measures to promote energy efficiency and conservation include education and publicity, the planned introduction of a voluntary energy efficiency labelling scheme, production of a compre- hensive set of building energy codes, promotion of energy audit and compilation of energy consumption data for various sectors of the economy. Control over the maximum overall thermal transfer value of new commercial and hotel buildings is expected to be introduced in early 1995. This will be complemented by energy codes for other aspects of building services design, including lighting and air-conditioning, which are now being developed.
Climate
Hong Kong's climate is sub-tropical, tending towards the temperate for nearly half the year. During November and December, there are pleasant breezes, plenty of sunshine and comfortable temperatures. Many people regard these as the best months of the year. January and February are more cloudy, with occasional cold fronts followed by dry northerly winds. It is not uncommon for temperatures to drop below 10°C in urban areas. The - lowest temperature ever recorded at the Royal Observatory was 0°C, although sub-zero
temperatures and frost occur at times on high ground and in the New Territories.
March and April can also be very pleasant although there are occasional spells of high humidity. Fog and drizzle can be particularly troublesome on high ground exposed to the southeast, and air traffic and ferry services are occasionally disrupted because of reduced visibility.
May to August are hot and humid with occasional showers and thunderstorms, particularly during the mornings. Afternoon temperatures often exceed 31°C, but at night temperatures generally remain around 26°C with high humidity. There is usually a fine dry spell in July which may last for one to two weeks, or even longer in some years. (See The Year's Weather entry for July in Appendix 50.)
September is the month during which Hong Kong is most likely to be affected by typhoons, although tropical cyclones of varying strength are not unusual at any time between May and November. On average, about 31 tropical cyclones form over the western North Pacific and China seas every year, and about half of them reach typhoon strength with maximum winds of 118 kilometres per hour or more.
When a tropical cyclone is about 700 to 1 000 kilometres southeast of Hong Kong, the weather is usually fine and exceptionally hot, but isolated thunderstorms sometimes occur in the evenings. If the cyclone's centre comes closer to the territory, winds will increase and rain can become heavy and widespread. The heavy rain may last for a few days, and subsequent landslips and flooding sometimes cause considerably more damage than the winds.
The mean annual rainfall ranges from around 1 300 millimetres at Waglan Island to more than 3 000 millimetres in the vicinity of Tai Mo Shan. About 80 per cent of the rain falls between May and September. The wettest month is August, when rain occurs about four