Script: Listening Plus - The heat island effect

Script: Listening Plus - The heat island effect

Kit: Hello, this is listening plus and you are with Young Post reporter Lai Ying-kit. This week we will be discussing a hot environmental topic, the wall-like high buildings in the city and the heat island effect that they cause. Joining me to discuss is senior reporter Olga Wong. She reports on environment and development issues for the South China Morning Post. So, Olga, can you tell us what the heat island effect is?

Olga: Ok, heat island effect describes the occurrence of build up areas being hotter than nearby rural areas. So temperatures are much higher in the down town area, compared to the countryside. Unfortunately, most of Hong Kong Island and Kowloon is very built up so this effect has a special importance to our city.

Kit: I understand that the government has released the city's first climatic map. Can you tell us more about that?

Olga: Sure. The Planning Department commissioned a climatic map study in 2006. In the map you can read different temperatures of various urban areas in Hong Kong. So you will find a dozen densely populated urban areas which are very hot. For example, if you look at Sheung Wan, Central, Causeway Bay, Wan Chai, North Point. On the Kowloon side, you will see Tsim Sha Tsui, Tsuen Wan, Kwun Tong, Sham Shui Po, Mong Kok, Lai Chi Kok, and Tseung Kwan O in the New Territories. These areas are a bit hotter areas in rural side. So these areas are five degrees Celsius higher compared with an environment offering people thermal comfort. This kind of temperature is not just about the air temperature. The map has taken into account the development density, topography, wind velocity, humidity, radiation and human activity of each area to calculate the actual temperature of that district. So people can get to know how hot that area is.

Kit: Does the study point out any new developments that are likely to make our urban area even hotter?

Olga: The professor of the study mentions that there are two developments in Tsim Sha Tsui that can add one or two degrees to the district. The first one is the Masterpiece, the recently completed high rise in Tsim Sha Tsui where you can find a lot luxurious apartments. It makes the district much hotter because of its large podium which blocks the air flow of the district. The other one is the newly refurbished monument in Tsim Sha Tsui which was the former Marine Headquarters. The reason for that development enhancing the district's temperatures is that the developer has removed one of the largest green slopes in the district and replaced it with a three-storey shopping mall and that new development is now named Heritage 1881.

Kit: So what are the study's team suggestions?

Olga: The study team suggested that developers should mitigate for what they have done. The developers are being urged to undo the damage they have done to the residents' quality of life by implementing a few mitigating measures to protect a few breezeways in Hong Kong. A few examples are Kowloon City, Ma Tau Kok, West Kowloon, Shek Kip Mei, etc. And another suggestion is that the developers should add greening to their developments at about 30 per cent of that development site's area and they should use building materials that absorb less heat and therefore make the area cooler. And, last but not least, they should provide shading areas in the district. The government should reserve some building-free zone in hot spots, which means some areas should be protected from dense developments.

Kit: So there are in fact quite a number of suggestions given by the study team. And what has been the government reaction to the heat effects of high buildings?

Olga: In fact the government pledged in May this year that all newly built government building with a floor area of more than 10,000 sq metres should be certified through the green labelling scheme. The government building should be certified with a green label showing that the development is environment friendly and will not block the air flow of the district. However, little drastic measures have been done so far.

Kit: Can you talk about how overseas cities have dealt with this problem?

Olga: This climatic map is not new in Europe and some developed countries in Asia. In Germany, the further road building law states that developments must not worsen the environment. The country has actually drawn up a climatic map, as early as in the 1980s. And a team of experts have been hired to advise planners on development scales and designs. In Toyko, the Tokyo government already launched a similar initiative in 2002 and they are now discussing with the developers and drawing up a plan that could demolish over-packed building blocks along a road called Kanni Road so that sea breezes could be brought back to the city.

Kit: There is a council for promoting sustainable development in Hong Kong. How about their reaction to the heat island effect in the city

Olga: The council launched a public consultation on some building regulations a few months ago. During the consultation, the council will gauge public views on whether developers should be asked to leave wider pedestrian streets and whether they should be banned from building podium structures. But whether to implement it by law or with incentives it is still subject to heated debate among interested parties. So no timetable has been set so far.

Kit: What does the Professional Green Building Council have to say?

Olga: I talked to the chairman of the Professional Green Building Council, Wong Kam-sing. Mr Wong told me that a new green building council will be set up next month and that it will revamp the existing labelling scheme for green buildings. Under the new proposal, the labelling scheme will force developers to conduct air ventilation studies if the developers want to get certification from that labelling scheme. The reason why they have to conduct an air ventilation study is because they have to demonstrate that their developments will have no or little impact on the wind environment of that district. Mr Wong said the result of the air ventilation study will become an influential factor in the new scheme of assessment.

Kit: Ok. Thank you, Olga. Thank you for giving us a comprehensive wrap-up on one of the key environmental issues that affect many Hong Kong people's life.

Olga: Thanks.


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