The event should instead be classified as a natural/technological disaster.

In a study last year by Leong Wai-siu and Melissa A. Hart ("Quantifying urban heat island intensity in Hong Kong SAR, China"), the most representative urban and non-urban station was found to be the Observatory's headquarters station and the Pak Tam Chung station respectively. If global warming is indeed taking place to generate more climatic disasters, why should annual mean temperatures between the two stations differ by as much as 3.8 degrees Celsius?

An important step in raising extreme weather awareness is to learn from past climatic disasters. One challenge is to be able to separate whether they were naturally or technologically driven.

Heat generation through population growth and lifestyle changes falls clearly into the technological category.

When I read all the comments about the behaviour of mainlanders in Hong Kong, I cannot help thinking about what I see when driving through Fenwick Street, Wan Chai, in the morning.

There are substantial quantities of litter, especially on a Thursday morning, with blatant disrespect for the old lady street cleaners. Wednesday night being ladies' night in bars makes me conclude that expatriate ladies are especially messy. You see all kinds of litter, including broken beer bottles.

Somebody is not doing their job here, be it the government or the bar owners (I could mention the names). Some of them are owned by large companies and it is scandalous.

One group of people obviously does not have the monopoly of bad behaviour.

M. Liedts, Wan Chai

Since the group of planners announced their vision of Des Voeux Road Central, correspondents and columnists have given their enthusiastic thumbs up, but all express pessimism that any positive action will be taken by government.

Why must we now wait until 2020 for such a good idea to materialise?

Prior to 1997, our government was proactive, decisive and could take action. US president Theodore Roosevelt said, "In any moment of decision, the best thing you can do is the right thing, the next best thing is the wrong thing, and the worst thing you can do is nothing."

Our present civil service has turned this upside down and seems to follow the dictum of "why make a decision when you can procrastinate or have another public consultation".

Our bureaucrats urgently need a change of mindset, as it appears that they have taken the mainland authorities' statement of "no change for 50 years" much too literally. Where there is a will, there is a way.

If getting buses off Des Voeux Road is so difficult, then allow some routes to still use this thoroughfare, but in procession with the trams.

Such a tandem method would not create delays, once private cars, vans and trucks are prohibited.

It is not just Central that would benefit from putting pedestrians first. All districts offer opportunities for such precincts. The district councils should be much more proactive.

In Wan Chai, there have been long-standing plans to consider such zones at Johnston Road, Spring Garden Lane, and parts of Lockhart Road, but nothing gets done.

No wonder Singapore is leaving us behind in environmental planning, architecture and cityscapes.

Earlier this month, three parcels apparently containing human excrement were sent to the office and home of commerce minister Greg So Kam-leung.

Whoever sent these parcels was obviously angry with what Mr So said.

I have to admit that I was unhappy with what Mr So said and believe he was irresponsible.

I agree we should show tolerance towards other people. However, when a problem clearly exists which is of concern to residents, the government should be dealing with it.

That said, sending such parcels is not the right way to make your voice heard. It is a very immature act and I would assume that those who did so were breaking the law.

Such actions will not sway officials in any way and this kind of insulting behaviour should always be condemned. Also, an act like this could actually increase tensions that already exist between mainlanders and Hongkongers and this undermines a harmonious society.

What Hongkongers do want is for the government to tackle the social problems created by large numbers of mainland visitors.

Any comments that people wish to make on this issue should be done in a peaceful way and we should always be willing to listen to opposing views, even if we think they are wrong.

There are options available to Hong Kong citizens to express their opinions regarding government policies and officials in a peaceful and legal way, such as through the media and joining protests.

These are tactics which are morally sound and far more effective than sending such offensive parcels.

Shirley Sham Wing-yin, Kowloon Tong

My blood boils when I hear legislative councillors calling for Legco's Powers and Privileges Ordinance to be invoked to set up a select committee to probe the delay in finishing the high-speed railway link to the mainland.

Calls for a probe by lawmakers came within days of the delay being announced by the head of the MTR Corporation.

However, it is a completely different story when it comes to the Airport Authority.

For years there have been reports alleging waste by the authority, such as the sums spent on the white elephant known as Terminal 2.

Then we have the proposed third runway, estimated to cost HK$130 billion. With skyrocketing construction costs over the last few years, the bill for a runway that many doubt Hong Kong needs could be well over HK$500 billion.

Writing to these columns last August, Dora Li called for an independent consultant study to see if Hong Kong really needed the runway rather than relying on studies financed and sponsored by the authority.

She also asked for details to be given of the costs of these sponsored studies.

Secretary for Transport and Housing Professor Anthony Cheung Bing-leung has had to take a lot of flak in the Legislative Council over the high-speed-rail fiasco. He should prepare himself for the same thing happening in the future with regard to the airport.

Flora Wong, Mong Kok

So many Hong Kong parents want their children to be competitive and successful.

Because of this, they are often pushed into activities such as piano lessons. The city produces many children who have passed piano exams but none emerge as internationally renowned pianists. As they are forced into these activities, their passion for a subject and their creativity are often extinguished.

Some young children may have been playing piano since kindergarten to help them get into a good school and may even have a grade eight ranking, but they are unable to appreciate the beauty of music. In a sense, they have become like machines.

These pushy parents see such lessons as a means to an end. If the children actually said they wanted to become professional pianists, the parents would discourage them from doing so.

This shows the intolerant and narrow side of our society.

In our education system we should be encouraging youngsters to show their creativity. Hong Kong cannot remain competitive if it does not have young people who are creative.